
[Federal Register: May 28, 2010 (Volume 75, Number 103)]
[Rules and Regulations]               
[Page 30159-30195]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr28my10-16]                         


[[Page 30159]]

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Part III





Department of Transportation





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Federal Aviation Administration



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14 CFR Part 91



Automatic Dependent Surveillance--Broadcast (ADS-B) Out Performance 
Requirements To Support Air Traffic Control (ATC) Service; Final Rule


[[Page 30160]]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 91

[Docket No. FAA-2007-29305; Amdt. No. 91-314]
RIN 2120-AI92

 
Automatic Dependent Surveillance--Broadcast (ADS-B) Out 
Performance Requirements To Support Air Traffic Control (ATC) Service

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: This final rule amends FAA regulations by adding equipage 
requirements and performance standards for Automatic Dependent 
Surveillance--Broadcast (ADS-B) Out avionics on aircraft operating in 
Classes A, B, and C airspace, as well as certain other specified 
classes of airspace within the U.S. National Airspace System (NAS). 
ADS-B Out broadcasts information about an aircraft through an onboard 
transmitter to a ground receiver. Use of ADS-B Out will move air 
traffic control from a radar-based system to a satellite-derived 
aircraft location system. This action facilitates the use of ADS-B for 
aircraft surveillance by FAA and Department of Defense (DOD) air 
traffic controllers to safely and efficiently accommodate aircraft 
operations and the expected increase in demand for air transportation. 
This rule also provides aircraft operators with a platform for 
additional flight applications and services.

DATES: This final rule is effective on August 11, 2010. The compliance 
date for this final rule is January 1, 2020. Affected parties, however, 
do not have to comply with the information collection requirement in 
Sec.  91.225 until the FAA publishes in the Federal Register the 
control number assigned by the Office of Management and Budget (OMB) 
for this information collection requirement. Publication of the control 
number notifies the public that OMB has approved this information 
collection requirement under the Paperwork Reduction Act of 1995. The 
incorporation by reference of certain publications listed in the rule 
is approved by the Director of the Federal Register as of August 11, 
2010.

FOR FURTHER INFORMATION CONTACT: For technical questions concerning 
this final rule, contact Vincent Capezzuto, Surveillance and Broadcast 
Services, AJE-6, Air Traffic Organization, Federal Aviation 
Administration, 800 Independence Avenue, SW., Washington, DC 20591; 
telephone (202) 385-8637; e-mail vincent.capezzuto@faa.gov.
    For legal questions concerning this final rule, contact Lorelei 
Peter, Office of the Chief Counsel, AGC-220, Federal Aviation 
Administration, 800 Independence Avenue, SW., Washington, DC 20591; 
telephone 202-267-3134; e-mail lorelei.peter@faa.gov.

SUPPLEMENTARY INFORMATION:

Authority for This Rulemaking

    The FAA's authority to issue rules on aviation safety is found in 
Title 49 of the United States Code (49 U.S.C.). Subtitle I, Section 
106, describes the authority of the FAA Administrator. Subtitle VII, 
Aviation Programs, describes in more detail the scope of the agency's 
authority.
    This rulemaking is promulgated under the authority described in 
Subtitle VII, Part A, Subpart I, Section 40103, Sovereignty and use of 
airspace, and Subpart III, Section 44701, General requirements. Under 
section 40103, the FAA is charged with prescribing regulations on the 
flight of aircraft (including regulations on safe altitudes) for 
navigating, protecting, and identifying aircraft, and the efficient use 
of the navigable airspace. Under section 44701, the FAA is charged with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce.
    This regulation is within the scope of sections 40103 and 44701 
because it prescribes aircraft performance requirements to meet 
advanced surveillance needs to accommodate increases in NAS operations. 
As more aircraft operate within the U.S. airspace, improved 
surveillance performance is necessary to continue to balance the growth 
in air transportation with the agency's mandate for a safe and 
efficient air transportation system.

Guide to Terms and Acronyms Frequently Used in This Document

ACI-NA--Airports Council International-North America
ACSS--Aviation Communication and Surveillance Systems
ADIZ--Air Defense Identification Zone
ADS-B--Automatic Dependent Surveillance-Broadcast
ADS-C--Automatic Dependent Surveillance-Contract
ADS-R--Automatic Dependent Surveillance-Rebroadcast
AGL--Above Ground Level
AIA--Aerospace Industries Association of America
ALPA--Air Line Pilots Association, International
AOPA--Aircraft Owners and Pilots Association
ARC--Aviation Rulemaking Committee
ASA--Aircraft Surveillance Applications
ASAS--Aircraft Surveillance Applications System
ASDE-X--Airport Surface Detection Equipment, Model X
ASSA--Airport Surface Situational Awareness
ATC--Air Traffic Control
CAA--Cargo Airline Association
CDTI--Cockpit Display of Traffic Information
CNS--Communication, Navigation, and Surveillance
EAA--Experimental Aircraft Association
ELT--Emergency Locator Transmitter
ES--Extended Squitter
EUROCAE--European Organisation for Civil Aviation Equipment
EUROCONTROL--European Organisation for the Safety of Air Navigation
FAROA--Final Approach Runway Occupancy Awareness
FedEx--Federal Express
FIS-B--Flight Information Service-Broadcast
FL--Flight Level
GA--General Aviation
GAMA--General Aviation Manufacturers Association
GNSS--Global Navigation Satellite System
GPS--Global Positioning System
HAI--Helicopter Association International
IATA--International Air Transport Association
ICAO--International Civil Aviation Organization
MHz--Megahertz
MOPS--Minimum Operational Performance Standards
MSL--Mean Sea Level
NACP--Navigation Accuracy Category For Position
NACV--Navigation Accuracy Category for Velocity
NAS--National Airspace System
NBAA--National Business Aviation Association
NextGen--Next Generation Air Transportation System
NIC--Navigation Integrity Category
NM--Nautical Mile
NPRM--Notice of Proposed Rulemaking
NTSB--National Transportation Safety Board
OPD--Optimized Profile Descent
OMB--Office of Management and Budget
RAA--Regional Airline Association
RAIM--Receiver Autonomous Integrity Monitoring
RFA--Regulatory Flexibility Act
RNP--Required Navigation Performance
SANDIA--Sandia National Laboratories
SARPs--Standards and Recommended Practices
SCAP--Security Certification and Accreditation Procedures
SDA--System Design Assurance
SIL--Source Integrity Level
SSR--Secondary Surveillance Radar
TCAS--Traffic Alert and Collision and Avoidance System
TIS-B--Traffic Information Service-Broadcast
TMA--Traffic Management Advisor

[[Page 30161]]

TSO--Technical Standard Order
UAT--Universal Access Transceiver
UPS--United Parcel Service
URET--User Request Evaluation Tool
VFR--Visual Flight Rules
WAAS--Wide Area Augmentation System

Table of Contents

I. Background
    A. Notice of Proposed Rulemaking
    B. ADS-B Aviation Rulemaking Committee
    C. Summary of the Final Rule
    1. Airspace
    2. Datalink Requirements
    3. System Performance Requirements
    4. Antenna Diversity and Transmit Power Requirements
    5. Latency of the ADS-B Out Message Elements
    6. Conforming Amendments and Editorial Changes
    D. Differences Between the Proposed Rule and The Final Rule
    E. Separation Standards Working Group
II. Discussion of the Final Rule
    A. Airspace
    1. 2,500 Feet Above Ground Level Exclusion in Class E Airspace
    2. Airspace for Which ADS-B is Required
    3. Requests for Deviations From ADS-B Out Requirements
    B. Dual-Link Strategy
    1. Altitude To Require the 1090 MHz ES Datalink
    2. Automatic Dependent Surveillance-Rebroadcast (ADS-R)
    3. 1090 MHz Frequency Congestion
    C. Performance Requirements--System
    1. Performance Requirements Tailored to Operator, Airspace, or 
Procedure
    2. Navigation Accuracy Category for Position (NACP)
    3. Navigation Accuracy Category for Velocity (NACV)
    4. Navigation Integrity Category (NIC)
    5. Surveillance Integrity Level
    6. Source Integrity Level (SIL) and System Design Assurance 
(SDA)
    7. Secondary Position Sources
    D. Performance Requirements--Antenna Diversity
    E. Performance Requirements--Transmit Power
    F. Performance Requirements--Total and Uncompensated Latency
    G. Performance Requirements--Time To Indicate Accuracy and 
Integrity Changes
    H. Performance Requirements--Availability
    1. Preflight Determination of Availability
    2. System Availability
    I. Performance Requirements--Continuity
    J. Performance Requirements--Traffic Information Service--
Broadcast Integrity (TIS-B)
    K. Broadcast Message Elements
    1. NACP/NACV/NIC/SDA/SIL
    2. Receiving ATC Services
    3. Length and Width of the Aircraft
    4. Indication of the Aircraft's Barometric Pressure Altitude
    5. Indication of the Aircraft's Velocity
    6. Indication if Traffic Alert and Collision Avoidance System II 
or Airborne Collision Avoidance System is Installed and Operating in 
a Mode That May Generate Resolution Advisory Alerts
    7. For Aircraft With an Operable Traffic Alert and Collision 
Avoidance System II or Airborne Collision Avoidance System, 
Indication If a Resolution Advisory Is in Progress
    8. Indication of the Mode 3/A Transponder Code Specified by ATC 
(Requires Flightcrew Entry)
    9. Indication of the Aircraft's Call Sign That Is Submitted on 
the Flight Plan, or the Aircraft's Registration Number (Aircraft 
Call Sign Requires Flight Crew Entry)
    10. Indication if the Flight Crew Has Identified an Emergency, 
Radio Communication Failure, or Unlawful Interference (Requires 
Flightcrew Entry)
    11. Indication of the Aircraft's ``IDENT'' to ATC (Requires 
Flightcrew Entry)
    12. Indication of the Emitter Category
    13. Indication Whether an ADS-B in Capability Is Installed
    14. Indication of the Aircraft's Geometric Altitude
    L. Ability To Turn Off ADS-B Out Transmissions
    M. Existing Equipment Requirements
    1. Transponder Requirement
    2. Emergency Locator Transmitter Requirement
    N. Program Implementation
    1. Timeline
    2. Financial and Operational Incentives
    3. Decommissioning Traffic Information Service-Broadcast (TIS-B)
    O. Safety
    P. Efficiency
    1. Improved Position Reporting
    2. Optimized Profile Descents (OPDs)
    3. Reduced Aircraft Separation
    4. Expanded Surveillance Coverage
    Q. ADS-B In
    R. ADS-B In Applications
    1. Surface Situational Awareness With Indications and Alerting
    2. In-Trail Procedures
    3. Interval Management
    4. Airport Surface Situational Awareness and Final Approach 
Runway Occupancy Awareness
    S. International Harmonization
    T. Backup ATC Surveillance
    U. Privacy
    V. Security
    W. Alternatives to ADS-B
    X. ADS-B Equipment Scheduled Maintenance
    Y. Specific Design Parameters
    Z. Economic Issues
    1. ADS-B Out Equipage Cost
    2. FAA Cost Savings With ADS-B Out Compared To Radar
    3. Business Case for ADS-B Out and In
    4. Improved En Route Conflict Probe Benefit Performance
    5. Capacity Enhancements, Airspace Efficiency, and Fuel Savings 
Benefits
    6. Deriving Benefits From Capstone Implementation in Alaska
    7. Regional Airline Benefits
    8. General Aviation: High Equipage Costs With Little Benefit
    AA. Revisions to Other Regulations
III. Regulatory Notices and Analyses
    A. Paperwork Reduction Act
    B. International Compatibility
    C. Regulatory Impact Analysis, Regulatory Flexibility 
Determination, International Trade Impact Analysis, and Unfunded 
Mandates Assessment
VI. Executive Order 13132, Federalism
VII. Regulations Affecting Intrastate Aviation in Alaska
VIII. Environmental Analysis
IX. Regulations That Significantly Affect Energy Supply, 
Distribution, or Use
X. Availability of Rulemaking Documents

I. Background

    While there is currently a drop in air travel due to a general 
economic downturn, delay and congestion continue to build in the 
nation's busiest airports and the surrounding airspace. The FAA must 
not only address current congestion, but also be poised to handle 
future demand that will surely return as the nation's economy improves. 
The FAA has been developing the Next Generation Air Transportation 
System (NextGen) for the purpose of changing the way the National 
Airspace System (NAS) operates. NextGen will allow the NAS to expand to 
meet future demand and support the economic viability of the system. In 
addition, NextGen will improve safety and support environmental 
initiatives such as reducing congestion, noise, emissions and fuel 
consumption through increased energy efficiency. for more information 
on NextGen, go to http://www.faa.gov/about/initiatives/nextgen/.
    As part of NextGen development, the FAA has determined that it is 
essential to move from ground-based surveillance and navigation to more 
dynamic and accurate airborne-based systems and procedures if the 
agency is to enhance capacity, reduce delay, and improve environmental 
performance. Automatic Dependent Surveillance-Broadcast (ADS-B) 
equipment is an advanced surveillance technology that combines an 
aircraft's positioning source, aircraft avionics, and a ground 
infrastructure to create an accurate surveillance interface between 
aircraft and ATC. It is a key component of NextGen that will move air 
traffic control (ATC) from a radar-based system to a satellite-derived 
aircraft location system. ADS-B is a performance-based surveillance 
technology that is more precise than radar. ADS-B is expected to 
provide air traffic controllers and pilots with more accurate 
information to help keep aircraft safely separated in the sky and on 
runways. The technology combines a positioning capability, aircraft 
avionics, and ground infrastructure to enable more accurate 
transmission of information from aircraft to ATC.
    ADS-B consists of two different services: ADS-B Out and ADS-B In. 
ADS-B Out, which is the subject of this

[[Page 30162]]

rulemaking, periodically broadcasts information about each aircraft, 
such as identification, current position, altitude, and velocity, 
through an onboard transmitter. ADS-B Out provides air traffic 
controllers with real-time position information that is, in most cases, 
more accurate than the information available with current radar-based 
systems. With more accurate information, ATC will be able to position 
and separate aircraft with improved precision and timing.
    ADS-B In refers to an appropriately equipped aircraft's ability to 
receive and display another aircraft's ADS-B Out information as well as 
the ADS-B In services provided by ground systems, including Automatic 
Dependent Surveillance-Rebroadcast (ADS-R),\1\ Traffic Information 
Service-Broadcast (TIS-B),\2\ and, if so equipped, Flight Information 
Service-Broadcast (FIS-B).\3\ When displayed in the cockpit, this 
information greatly improves the pilot's situational awareness in 
aircraft not equipped with a traffic alert and collision avoidance 
system (TCAS)/airborne collision avoidance system (ACAS). Benefits from 
universal equipage for ADS-B In currently are not substantiated, and 
standards for ADS-B In air-to-air applications are still in their 
infancy. Thus it is premature to require operators to equip with ADS-B 
In at this time. This rule, however, imposes certain requirements that 
will support some ADS-B In applications.
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    \1\ ADS-R collects traffic information from each broadcast link 
and rebroadcasts it to ADS-B In-equipped operators on the other 
broadcast link. This is further explained in section B.2., Automatic 
Dependent Surveillance-Rebroadcast.
    \2\ TIS-B uses primary and secondary surveillance radars and 
multilateration systems to provide proximate traffic situational 
awareness, including position reports from aircraft not equipped 
with ADS-B. TIS-B data may not provide as much information as could 
be received directly from an aircraft's ADS-B Out broadcast, because 
of the required data processing. The TIS-B signal is an advisory 
service that is not designed for aircraft surveillance or 
separation, and cannot be used for either purpose.
    \3\ With FIS-B, aircraft equipped with 978 megahertz (MHz) 
Universal Access Transceiver (UAT) ADS-B In avionics can receive 
weather information, notices to airmen, temporary flight 
restrictions, and other relevant flight information, at no 
additional cost.
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    As noted in the preamble of the Notice of Proposed Rulemaking 
(NPRM) associated with this rule, published in the Federal Register on 
October 5, 2007 (72 FR 56947), Congress enacted the ``Century of 
Aviation Reauthorization Act'' in 2003. That Act mandated that the 
Secretary of Transportation establish a Joint Planning and Development 
Office (JPDO) to manage NextGen-related work, including coordinating 
the development and use of new technologies for aircraft in the air 
traffic control system. Since 2006, Congress has appropriated over $500 
million to the FAA for implementing ADS-B and developing air-to-air 
capabilities. The FAA remains committed to implementing NextGen and 
adopts this final rule, with some modifications, as discussed in 
further detail below.

A. Notice of Proposed Rulemaking

    The FAA published the NPRM for ADS-B Out in the Federal Register on 
October 5, 2007 (72 FR 56947). The comment period for the NPRM was 
scheduled to close on January 3, 2008. In response to several 
commenters, the FAA subsequently extended the comment period to March 
3, 2008 (72 FR 64966, Nov. 19, 2007). The FAA received approximately 
190 comments to the docket on the NPRM. Commenters included air 
carriers, manufacturers, associations, Government agencies, and 
individuals.

B. ADS-B Aviation Rulemaking Committee

    As part of the rulemaking effort, the FAA chartered an aviation 
rulemaking committee (ARC) on July 15, 2007, to provide a forum for the 
U.S. aviation community to make recommendations on presenting and 
structuring an ADS-B Out mandate, and to consider additional actions 
that may be necessary to implement its recommendations. The ADS-B ARC 
submitted its first report, ``Optimizing the Benefits of Automatic 
Dependent Surveillance-Broadcast,'' \4\ on October 3, 2007.
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    \4\ A copy of this report is available from the Web site http://
www.regulations.gov. To find the report, enter FAA-2007-29305-0009.1 
in the search field.
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    The FAA also tasked the ARC to make specific recommendations 
concerning the proposed rule based on the comments submitted to the 
docket. The ARC submitted its second report, ``Recommendations on 
Federal Aviation Administration Notice No. 7-15, Automatic Dependent 
Surveillance-Broadcast (ADS-B) Out Performance Requirements to Support 
Air Traffic Control (ATC) Service; Notice of Proposed Rulemaking,'' \5\ 
to the FAA on September 26, 2008.
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    \5\ A copy of this report is available from the Web site http://
www.regulations.gov. To find the report, enter FAA-2007-29305-0221.1 
in the search field
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    To give the public an opportunity to comment on the recommendations 
received from the ARC, the FAA published a notice in the Federal 
Register on October 2, 2008 (73 FR 57270), reopening the comment period 
of the ADS-B Out NPRM docket for an additional 30 days. The purpose of 
reopening the comment period was to receive public comments on the ARC 
recommendations only. This comment period closed November 3, 2008, with 
the FAA receiving approximately 50 comments to the ARC's 
recommendations. Commenters included air carriers, manufacturers, 
associations, and individuals.

C. Summary of the Final Rule

    This final rule will add equipage requirements and performance 
standards for ADS-B Out avionics. ADS-B Out broadcasts information 
about an aircraft through an onboard transmitter to a ground receiver. 
Use of ADS-B Out will move air traffic control from a radar-based 
system to a satellite-derived aircraft location system. As discussed 
more fully in the sections of this preamble describing equipage 
requirements and performance standards, operators will have two options 
for equipage under this rule--the 1090 megahertz (MHz) extended 
squitter \6\ (ES) broadcast link or the Universal Access Transceiver 
(UAT) broadcast link. \7\ Generally, this equipment will be required 
for aircraft operating in Classes A, B, and C airspace, certain Class E 
airspace, and other specified airspace. See section C.1. ``Airspace'' 
below for additional details.
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    \6\ An extended squitter is a long message that Mode S 
Transponders transmit automatically, without needing to be 
interrogated by radar, to announce the own-ship aircraft's presence 
to nearby ADS-B equipped aircraft or ground based Air Traffic 
Control.
    \7\ The 1090 MHz ES broadcast link uses the 1090 MHz frequency. 
The UAT broadcast link uses the 978 MHz frequency.
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    The NPRM proposed performance requirements for ADS-B Out to be used 
for ATC surveillance. In addition, several aspects of the proposal 
would be necessary for future ADS-B In applications. The comments to 
the NPRM and the ARC recommendations raised significant concerns about 
the operational needs and costs of the proposed performance 
requirements, as well as the proposed antenna diversity requirement.
    The FAA specifically proposed higher ADS-B Out and antenna 
diversity requirements than what is needed for ATC surveillance to 
enable certain ADS-B In applications. As discussed in further detail in 
this document, the FAA has reconsidered these elements in view of the 
comments and has changed the implementation plan for ADS-B.
    The FAA has concluded that this rule will require only the 
performance requirements necessary for ADS-B Out. While certain 
requirements adopted in this rule will support some ADS-B In 
applications, the agency is not adopting

[[Page 30163]]

the higher performance standards that would enable all of the initial 
ADS-B In applications. The agency is mindful, and operators are 
advised, that in accepting the commenters' and the ARC's positions 
regarding antenna diversity and position source accuracy, compliance 
with this rule alone may not enable operators to take full advantage of 
certain ADS-B In applications. Operators may voluntarily choose 
equipment that meets the higher performance standards in order to 
enable the use of these applications.
    The following table provides an overview of the costs and benefits 
of this final rule.

                      Summary of Costs and Benefits
------------------------------------------------------------------------

------------------------------------------------------------------------
3% Discount Rate:

  Low Costs.................................................      $2.74
  High Benefits.............................................       5.03
                                                             -----------
    Net Benefits-High Benefit/Low Cost......................       2.29
                                                             ===========
  High Costs................................................       5.47
  Low Benefits..............................................       3.98
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    Net Benefits-Low Benefits/High Costs....................      (1.49)
                                                             ===========

7% Discount Rate:

  Low Costs.................................................       2.15
  High Benefits.............................................       2.74
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    Net Benefits-High Benefit/Low Cost......................       0.59
                                                             ===========
  High Costs................................................       4.11
  Low Benefits..............................................       2.09
    Net Benefits-Low Benefits/High Costs....................      (2.02)
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1. Airspace
    This final rule prescribes ADS-B Out performance requirements for 
all aircraft operating in Class A, B, and C airspace within the NAS; 
above the ceiling and within the lateral boundaries of a Class B or 
Class C airspace area up to 10,000 feet mean sea level (MSL); and Class 
E airspace areas at or above 10,000 feet MSL over the 48 contiguous 
United States and the District of Columbia, excluding the airspace at 
and below 2,500 feet above the surface.
    The rule also requires that aircraft meet these performance 
requirements in the airspace within 30 nautical miles (NM) of certain 
identified airports \8\ that are among the nation's busiest (based on 
annual passenger enplanements, annual airport operations count, and 
operational complexity) from the surface up to 10,000 feet MSL. In 
addition, the rule requires that aircraft meet ADS-B Out performance 
requirements to operate in Class E airspace over the Gulf of Mexico at 
and above 3,000 feet MSL within 12 NM of the coastline of the United 
States.
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    \8\ These airports are listed in appendix D to part 91.
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2. Datalink Requirements
    ADS-B requires a broadcast link for aircraft surveillance and to 
support ADS-B In applications. Operators have two options for equipage 
under this rule-- the 1090 MHz ES broadcast link or the UAT broadcast 
link. The 1090 MHz ES broadcast link is the internationally agreed upon 
link for ADS-B and is intended to support ADS-B In applications used by 
air carriers and other high-performance aircraft. The 1090 MHz ES 
broadcast link does not support FIS-B (weather and related flight 
information) because the bandwidth limitations of this link cannot 
transmit the large message structures required by FIS-B. The UAT 
broadcast link supports ADS-B In applications \9\ and FIS-B, which are 
important for the general aviation (GA) community.
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    \9\ These applications include enhanced visual acquisition, 
conflict detection, enhanced visual approach, Airport Surface 
Situational Awareness (ASSA), and Final Approach Runway Occupancy 
Awareness (FAROA).
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    This final rule requires aircraft flying at and above 18,000 feet 
MSL (flight level (FL) 180) (Class A airspace) to have ADS-B Out 
performance capabilities using the 1090 MHz ES broadcast link. This 
rule also specifies that aircraft flying in the designated airspace 
below 18,000 feet MSL may use either the 1090 MHz ES or UAT broadcast 
link.
3. System Performance Requirements
    When activated, ADS-B Out continuously transmits aircraft 
information through the 1090 MHz ES or UAT broadcast link. The accuracy 
and integrity of the position information transmitted by ADS-B avionics 
are represented by the navigation accuracy category for position 
(NACP), the navigation accuracy category for velocity 
(NACV), the navigation integrity category (NIC), the system 
design assurance (SDA), and the source integrity level (SIL).
    In the proposed rule, the FAA referenced the accuracy and integrity 
requirements to the appropriate NACP, NACV, NIC, 
and SIL values defined in Technical Standard Order (TSO)-C166a \10\ 
(for operators using the 1090 MHz ES broadcast link), and TSO-C154b 
\11\ (for operators using the UAT broadcast link) as the baseline 
requirements for ADS-B Out equipment. TSO-C166a adopted the standards 
in RTCA, Inc.\12\ (RTCA) DO-260A.\13\ TSO-C154b adopted the standards 
in RTCA DO-282A.\14\
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    \10\ Extended Squitter Automatic Dependent Surveillance-
Broadcast (ADS-B) and Traffic Information Service--Broadcast (TIS-B) 
Equipment Operating on the Radio Frequency of 1090 Megahertz (MHz).
    \11\ Universal Access Transceiver (UAT) Automatic Dependent 
Surveillance--Broadcast (ADS-B) Equipment Operating on the Frequency 
of 978 MHz.
    \12\ RTCA, Inc. is a not-for-profit corporation formed to 
advance the art and science of aviation and aviation electronic 
systems for the benefit of the public. The organization functions as 
a Federal Advisory Committee and develops consensus-based 
recommendations on contemporary aviation issues. The organization's 
recommendations are often used as the basis for government and 
private sector decisions as well as the foundation for many FAA 
TSOs. For more information, see http://www.rtca.org.
    \13\ Minimum Operational Performance Standards for 1090 MHz 
Extended Squitter Automatic Dependent Surveillance--Broadcast (ADS-
B) and Traffic Information Services--Broadcast (TIS-B).
    \14\ Minimum Operational Performance Standards for Universal 
Access Transceiver (UAT) Automatic Dependent Surveillance--
Broadcast.
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    After the NPRM was published, the ADS-B ARC issued numerous 
recommendations in response to public comments on the TSOs referenced 
in the proposal. Based on the ARC recommendations and broad industry 
input, RTCA revised DO-260A to become DO-260B \15\ and revised DO-282A 
to become DO-282B.\16\ The new RTCA revisions include: (1) An allowance 
for transmitting a NIC of 7 on the surface, (2) procedures for 
correctly setting the NACV, (3) clarifying the latency 
requirements, (4) removing the vertical component of NACP, 
NACV, NIC, and SIL, (5) revising the definition of SIL to 
correspond to the definition in the FAA NPRM, (6) clarifying the 
definition of SIL by dividing it into SIL and SDA message elements, (7) 
creating a medium power single antenna class, and (8) redefining the 
bit for the ``ADS-B In capability installed'' message element.\17\ DO-
260B and DO-282B are more mature standards and fully support domestic 
and international ADS-B air traffic control surveillance. The updated 
standards do not increase performance requirements.
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    \15\ Minimum Operational Performance Standards for 1090 MHz 
Extended Squitter Automatic Dependent Surveillance-Broadcast (ADS-B) 
and Traffic Information Services-Broadcast (TIS-B).
    \16\ Minimum Operational Performance Standards for Universal 
Access Transceiver Automatic Dependent Surveillance-Broadcast.
    \17\ A number of these items address issues with the current 
TSOs.
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    The FAA updated the TSOs in accordance with these new RTCA 
standards. In addition, the FAA has

[[Page 30164]]

decided that it is necessary to require the new standards contained in 
TSO-C166b \18\ (1090 MHz ES) and TSO-C154c \19\ (UAT) as the minimum 
performance standards in this final rule.\20\ The updated standards 
incorporate multiple changes that address public comments and the ARC's 
recommendations on the proposal. On September 11, 2009, the FAA 
announced in the Federal Register the availability of draft TSO-C166b 
and TSO-C154c for comment (74 FR 46831). The FAA issued final versions 
of the above TSOs on December 2, 2009. The FAA also added additional 
language in Sec. Sec.  91.225 and 91.227 stating that equipment with an 
approved deviation under Sec.  21.618 also meet the requirements of the 
rule.
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    \18\ Extended Squitter Automatic Dependent Surveillance-
Broadcast (ADS-B) and Traffic Information Service-Broadcast (TIS-B) 
Equipment Operating on the Radio Frequency of 1090 Megahertz (MHz).
    \19\ Universal Access Transceiver (UAT) Automatic Dependent 
Surveillance-Broadcast (ADS-B) Equipment Operating on the Frequency 
of 978 MHz.
    \20\ Operators with equipment installed that meets a later 
version of TSO-C166b or TSO-C154c, as applicable, are in compliance 
with this rule.
---------------------------------------------------------------------------

    In addition, this final rule specifies the performance requirements 
for accuracy and integrity (NACP, NACV, and NIC) 
in meters and nautical miles rather than referencing the numerical 
values used in DO-260B, DO-282B, or the NPRM. This change translates 
the values but does not alter the actual performance requirements. The 
FAA wants to avoid any misinterpretations of the performance 
requirements for this rule, if in the future, RTCA revises 
NACP, NACV, and NIC.
    Table 1 summarizes the NACP, NACV, NIC, and 
SIL values proposed in the NPRM and their equivalent measurements, as 
noted in DO-260A and DO-282A. Table 2 summarizes NACP, 
NACV, NIC, SDA, and SIL values as defined in DO-260B and DO-
282B. These two tables contain only the values applicable to the NPRM 
and the final rule. See DO-260B paragraph 2.2.3 or DO-282B paragraph 
2.2.4 for complete information on all values.
[GRAPHIC] [TIFF OMITTED] TR28MY10.000


[[Page 30165]]


[GRAPHIC] [TIFF OMITTED] TR28MY10.001

    In this final rule, the NACP must be less than 0.05 NM. 
The NACV and NIC values are adopted as proposed. The 
NACV must be less than 10 meters per second. The NIC must be 
less than 0.2 NM. The SIL parameter from the NPRM has been divided into 
two separate parameters and is discussed in detail later in this 
document.\21\ In this final rule, the SDA parameter must be less than 
or equal to 1x10 -5 per hour, which is equivalent to an SDA 
of 2, and the SIL parameter must be less than or equal to 1x10 
-7 per hour or per sample, which is equivalent to a SIL of 
3. Global navigation satellite system (GNSS) systems \22\ will set 
their SILs based on a 1x10 -7 per-hour probability. 
Operators must meet these performance requirements to operate in the 
airspace where ADS-B is required. Any ADS-B position source that meets 
the specified performance standards is acceptable and complies with the 
requirements in the final rule.
---------------------------------------------------------------------------

    \21\ In the NPRM, SIL was defined as surveillance integrity 
level and represented the maximum probability of exceeding the NIC 
containment radius and a maximum probability of a failure causing 
false or misleading data to be transmitted. In this final rule, SIL 
is referred to as source integrity level and defines the probability 
of exceeding the NIC containment radius; SDA represents the 
probability of transmitting false or misleading position 
information.
    \22\ Global navigation satellite system (GNSS) is a generic term 
for a satellite navigation system, such as the Global Positioning 
System (GPS), that provides autonomous worldwide geo-spatial 
positioning and may include local or regional augmentations.
---------------------------------------------------------------------------

4. Antenna Diversity and Transmit Power Requirements
    The aircraft antenna is a major contributor to ADS-B system link 
performance and an important part of the overall ADS-B Out system. In 
the NPRM, the FAA proposed an antenna diversity requirement that would 
support ADS-B In applications, such as Airport Surface Situational 
Awareness (ASSA) and Final Approach Runway Occupancy Awareness (FAROA).
    The FAA has reconsidered the need for antenna diversity in view of 
the comments submitted. The agency has determined that a single bottom-
mounted antenna is the minimum requirement for ATC surveillance. 
Furthermore, the analysis of ASSA and FAROA does not conclude that 
antenna diversity is required for these applications. As discussed 
later, the FAA decision to require a NACP less than 0.05 NM 
signifies that certain ADS-B In applications, including ASSA and FAROA, 
will not be fully supported.
    If future analysis indicates that antenna diversity is required for 
ASSA and FAROA, a higher NACP than that required in this 
rule also would be necessary to support these applications. The FAA 
does not adopt antenna diversity as a requirement for ADS-B Out under 
this rule because it is not required to support ATC surveillance. 
Operators must note that this rule does not remove or modify any 
existing antenna diversity requirements for transponders or TCAS/ACAS.
    Aircraft must transmit signals at a certain level of power to 
ensure ground stations and ADS-B In-equipped aircraft and vehicles can 
receive the transmitted signals. As proposed, the final rule requires 
UAT systems to broadcast at a 16-watt minimum-transmit power, and 1090 
MHz ES systems to broadcast at a 125-watt minimum-transmit power.
5. Latency of the ADS-B Out Message Elements
    When using an ADS-B system, aircraft receive information from a 
position source and process it with onboard avionics. The aircraft's 
ADS-B system then transmits position and other information to the 
ground stations through antenna(s) using either the UAT or 1090 MHz ES 
broadcast link. Generally, latency is the time lag between the time 
that position measurements are taken to determine the aircraft's 
position, and the time that the position information is transmitted by 
the aircraft's ADS-B transmitter. The latency requirements in this 
final rule, although different from the proposal, represent a more 
appropriate way to address latency. The proposal created ambiguities 
that are addressed in these modifications and are supported by the 
commenters. Under this rule, total

[[Page 30166]]

latency cannot exceed 2.0 seconds. Within those 2.0 seconds, 
uncompensated latency cannot exceed 0.6 seconds. Total and 
uncompensated latency are explained in further detail in section II F. 
``Performance Requirements--Total And Uncompensated Latency.''
6. Conforming Amendments and Editorial Changes
    Section 91.225 requires ADS-B Out for operations in Class A, B, and 
C airspace. In the NPRM, the FAA inadvertently left out the proposed 
conforming amendments to Sec. Sec.  91.130, 91.131, and 91.135, which 
address Class A, B, and C airspace. This rule amends these sections to 
include the ADS-B Out performance requirements for the appropriate 
airspace.
    In addition, the regulatory text for Sec.  91.225 has been 
reorganized from the proposed rule language. The restructuring of the 
text should make this section clearer and more reader-friendly.
    Lastly, the proposed regulatory text has been moved from Appendix H 
to new Sec.  91.227.
    All substantive changes to this rule are fully discussed in Section 
II, Discussion of the Final Rule.

D. Differences Between the Proposed Rule and the Final Rule

    Table 3 summarizes the substantive changes between the proposed 
rule and this final rule. Editorial changes and clarifications are 
explained elsewhere in this preamble.

  Table 3.-- Substantive Differences Between the Proposed Rule and the
                               Final Rule
------------------------------------------------------------------------
         Issue area                The NPRM--         The final rule--
------------------------------------------------------------------------
Technical Standard Order....  Proposed performance  Requires performance
                               standards as          standards as
                               defined in TSO-       defined in TSO-
                               C166a (1090 MHz ES)   C166b (1090 MHz ES)
                               or TSO-C154b (UAT).   or TSO-C154c (UAT).
Airspace....................  Proposed requiring    Requires all
                               all aircraft above    aircraft in Class A
                               FL 240 to transmit    airspace (FL 180
                               on the 1090 MHz ES    and above) to
                               broadcast link.       transmit on the
                                                     1090 MHz ES
                                                     broadcast link.
                              Proposed ADS-B        Requires ADS-B
                               performance           performance
                               standards for         standards for
                               operations in all     operations in Class
                               Class E airspace at   E airspace at and
                               and above 10,000      above 10,000 feet
                               feet MSL.             MSL, excluding the
                                                     airspace at and
                                                     below 2,500 feet
                                                     AGL.
NACP........................  Proposed a NACP >=    Requires NACP < 0.05
                               9, which provides     NM.
                               navigation accuracy   (NACP >= 8)
                               < 30 meters.
NIC.........................  Proposed changes in   Requires changes in
                               NIC be broadcast      NIC be broadcast
                               within 10 seconds.    within 12 seconds.
SIL.........................  Proposed a SIL of 2   Requires an SDA of
                               or 3.                 2.
                                                     Requires a SIL of
                                                     3.
Antenna Diversity...........  Proposed antenna      Does not require
                               diversity in all      antenna diversity.
                               airspace specified
                               in the rule.
Total Latency...............  Proposed latency in   Requires
                               the position source   uncompensated
                               < 0.5 seconds and     latency <= 0.6
                               latency in the ADS-   seconds and maximum
                               B source < 1 second.  total latency <=
                                                     2.0 seconds.
Message Elements............  Proposed a broadcast  Does not require a
                               message element for   broadcast message
                               ``receiving ATC       element for
                               services''.           ``receiving ATC
                                                     services.''
An ability to turn off ADS-B  Proposed that the     Does not require the
 Out.                          pilot be able to      pilot be able to
                               turn off ADS-B        disable or turn off
                               transmissions if      ADS-B
                               directed by ATC.      transmissions.
------------------------------------------------------------------------

E. Separation Standards Working Group

    The FAA established an internal Surveillance and Broadcast Systems 
Separation Standards Working group (SSWG) to develop methodologies and 
define metrics as appropriate that evaluate the end-to-end performance 
of ADS-B and wide area multilateration surveillance systems. These 
evaluations include investigating the integration of these technologies 
in conjunction with legacy surveillance technologies, that is, 
separation between target positions that are derived from ADS-B, radar, 
and wide area multilateration on ATC displays.
    This SSWG was tasked to perform: (1) Analyses of performance using 
system models and simulations, including the identification of key 
performance drivers and the development of test scenarios; (2) 
preliminary evaluations with prototype system components to enable 
verification and validation of the models and as early evidence of 
system performance; and (3) analyses of test results, operational 
testing and dedicated separation standards flight tests for each key-
site with fully functional end-to-end systems. Also included is a test 
period for each system where performance data is collected on aircraft 
operating in the surveillance service volume.
    The SSWG analyses and evaluations are the basis for most of the 
performance requirements specified in this rule.\23\
---------------------------------------------------------------------------

    \23\ The SSWG findings are available from the Web site http://
www.regulations.gov. The docket number for this rulemaking is FAA -
2007-29305.
---------------------------------------------------------------------------

II. Discussion of the Final Rule

    Below is a more detailed discussion of the final rule relative to 
the comments received on the proposal:

A. Airspace

1. 2,500 Feet Above Ground Level Exclusion in Class E Airspace
    The NPRM proposed that aircraft meet ADS-B Out performance 
requirements to operate in Class E airspace at and above 10,000 feet 
MSL over the 48 contiguous states and the District of Columbia.
    Several commenters, including the DOD and the Experimental Aircraft 
Association (EAA), stated that the proposed ceiling of 10,000 feet MSL 
for aircraft without ADS-B would be a major hardship and safety issue 
for aircraft operators flying in mountainous terrain. Commenters and 
the ARC suggested that the final rule exclude Class E airspace at and 
below 2,500 feet above ground level (AGL), similar to the exclusion in 
Sec.  91.215, ATC Transponder and Altitude Reporting Equipment and Use.
    The FAA recognizes the benefit of excluding this airspace in the 
rule, particularly for visual flight rules (VFR) pilots flying in 
mountainous areas. This modification addresses airspace that is not 
affected by the agency's efforts to maximize NAS efficiency and 
capacity. Excluding this airspace from the rule minimizes any 
unnecessary financial and operational burdens being placed on aircraft 
operators who fly in mountainous areas that encroach on

[[Page 30167]]

Class E airspace at and above 10,000 feet MSL, but choose not to equip 
for the ADS-B Out performance standards in this rule. Consequently, the 
final rule does not require ADS-B performance standards for operations 
2,500 feet AGL and below in Class E airspace at and above 10,000 feet 
MSL.
2. Airspace for Which ADS-B Is Required
    The NPRM proposed requiring ADS-B performance standards for 
operations in most classes of airspace where operators currently are 
required to carry a transponder.
    Numerous commenters recommended that the FAA limit ADS-B 
performance requirements to aircraft operating in Class A airspace 
only, or Class A and B airspace only. Several commenters questioned the 
proposed ADS-B performance requirements in Class E airspace above 
10,000 feet MSL. Many of these commenters made varying requests to the 
FAA concerning the proposed altitude for which ADS-B Out would be 
required, including 12,000 feet MSL, 15,000 feet MSL, FL 180, and FL 
250. The United States Parachute Association noted that skydiving 
operations are typically conducted above 10,000 feet MSL and sometimes 
conducted in Class A, B, and C airspace.
    ADS-B cannot be used for ATC surveillance if all aircraft are not 
appropriately equipped. Moreover, it is unreasonable to set up a 
regulatory framework and performance standards that are based on using 
two primary systems for surveillance; nor is it feasible to fund and 
maintain two such systems. The airspace requirements specified in this 
rule for ADS-B Out meet ATC surveillance needs.
    Class B and C airspace have the highest volume of air carrier and 
GA traffic. They also experience the most complex transitions of 
aircraft from the en route environment to the terminal area. With the 
intricate nature of the airspace, current regulations dictate more 
stringent operational requirements to operate within Class B and C 
airspace areas.
    In addition, ATC must have surveillance data for all aircraft 
operating in these areas to ensure appropriate situational awareness 
and to maximize the use of the NAS. ADS-B Out will enhance surveillance 
in controlled airspace areas where secondary surveillance radar (SSR) 
currently exists.
    One commenter stated that the FAA should expand the airspace in 
which ADS-B is required and specifically recommended including Air 
Defense Identification Zones (ADIZ) \24\ and Offshore Control Area 
Extensions.
---------------------------------------------------------------------------

    \24\ An Air Defense Identification Zone (ADIZ) is an area of 
airspace over land or water in which the ready identification, 
location, and control of civil aircraft is required in the interest 
of national security.
---------------------------------------------------------------------------

    This rule applies to aircraft operating within U.S. airspace, which 
extends 12 NM from the U.S. coast. (The airspace also includes the 
Washington, DC, Special Flight Rules Area (SFRA), referred to as an 
``ADIZ'' prior to 2009.) Most of the airspace in the ADIZ falls outside 
the 12 NM boundaries.
3. Requests for Deviations From ADS-B Out Requirements
    This rule requires operators to broadcast ADS-B Out information 
when operating in specified airspace. If an aircraft is not capable of 
meeting the performance requirements, the operator may request a 
deviation from the ATC facility responsible for that airspace. However, 
as noted in the NPRM, ATC authorizations may contain conditions 
necessary to provide the appropriate level of safety for all operators 
in the airspace. ATC may not be able to grant authorizations in all 
cases for a variety of reasons, including workload, runway 
configurations, air traffic flows, and weather conditions.

B. Dual-Link Strategy

    The NPRM proposed a dual-link strategy for ADS-B Out broadcasts. 
Under the proposal, aircraft operating above FL 240 would be required 
to use the 1090 MHz ES broadcast link. Aircraft operating below FL 240 
and in airspace where ADS-B Out performance requirements were proposed 
could use either the 1090 MHz ES or UAT broadcast link.
    Many commenters suggested that a single-link system would reduce 
operational complexity. The commenters noted that the installation and 
maintenance costs of a dual-link system exceed those of a single-link 
system. Some of the commenters proposed a single-link solution but 
disagreed over which link should be chosen. Commenters supporting a 
single-link UAT system noted that 1090 MHz ES does not support FIS-B 
and is at risk for frequency congestion in a future air traffic 
management environment. Commenters supporting a single-link 1090 MHz ES 
system explained that UAT is not internationally interoperable and 
opposed a system that requires international operators to equip with 
both links.
    Boeing noted that most of the NAS system delays are associated with 
arrivals and departures. Therefore, Boeing recommended that the 
airborne surveillance functions should provide benefits at all 
altitudes and on the ground. Ultimately, Boeing commented that a single 
1090 MHz ES broadcast link would advance future ADS-B In applications 
at low altitudes.
    In mandating ADS-B, the FAA is mindful that some members of the 
international air transport community and the GA community have already 
purchased ADS-B Out equipment, which use either the 1090 MHz ES or UAT 
broadcast link. The FAA finds that a dual-link system is necessary for 
the United States to meet the operational needs of all NAS operators. 
Moreover, if the FAA were to require one segment of the aviation 
community to equip to meet the needs of another segment of the 
community, this would present additional costs for some operators to 
equip.
1. Altitude To Require the 1090 MHz ES Datalink
    Under the proposal, aircraft operating above FL 240 would be 
required to use the 1090 MHz ES broadcast link. Operators using only 
the UAT broadcast link would be limited to operations below FL 240.
    The Air Line Pilots Association, International (ALPA) recommended 
that the FAA require operators to use 1090 MHz ES above 18,000 feet MSL 
to be consistent with the Class A airspace lower boundary (rather than 
introduce a new subclassification of established airspace). In 
addition, several GA commenters requested limiting ADS-B performance 
requirements to only Class A airspace. The EAA and some individuals 
stated that UAT would work just as well as 1090 MHz ES above FL 240 and 
that aircraft should be permitted to use exclusively UAT for operations 
above FL 240.
    The final rule specifies FL 180 (the lower boundary of Class A 
airspace) as the ceiling for operating an aircraft equipped only with 
UAT. Using 1090 MHz ES at or above FL 180 provides a clear operational 
boundary for controllers and pilots, and does not create conditions of 
mixed equipage for existing or future applications. The FAA recognizes 
that this modification will affect certain operators that want to 
operate above FL 180 and equip only with UAT. However, the agency 
concludes that requiring 1090 MHz ES performance standards for 
operations in all of Class A airspace is not only reasonable for 
surveillance, but also establishes a baseline for ADS-B In.
    The requirement to broadcast 1090 MHz ES at and above FL 180 does 
not

[[Page 30168]]

preclude UAT reception of FIS-B services up to FL 240 for aircraft with 
a dual-link reception capability.
2. Automatic Dependent Surveillance-Rebroadcast (ADS-R)
    Under a dual-link strategy, the FAA will use ADS-R to allow ADS-B 
In-equipped aircraft using one type of broadcast link to receive 
messages about aircraft transmitting on the other broadcast link.
    Various commenters, including the Air Transport Association of 
America, Inc. (ATA), Airservices Australia, the Australia Civil 
Aviation Safety Authority, the Aircraft Owners and Pilots Association 
(AOPA), Boeing, British Airways, and the International Air Transport 
Association (IATA), expressed concern about a dual-link system. Some of 
these commenters asserted that the need for ADS-R introduces additional 
system-wide latency into the ADS-B system and poses a single point of 
failure for the degradation or loss of surveillance data. In their 
view, this could limit potential separation and efficiency improvements 
and affect the air-to-air surveillance element of future ADS-B In 
applications. In addition, some commenters expressed concern about the 
additional risk of faults or failures that could result from 
translating, merging, and rebroadcasting data from the 1090 and 978 MHz 
frequencies.
    Some commenters, including Boeing, contended that ADS-R may not 
have sufficient growth capability to support future ADS-B In air-to-air 
applications. Such applications include merging and spacing, self 
separation, or using ADS-B data to supplement or replace TCAS because 
of potential of latency or loop delays. Rockwell-Collins stated that 
ADS-R should be able to support many ADS-B In air-to-air applications, 
including closely spaced parallel approaches and enhanced visual 
approach. It recommended developing ADS-R to support more demanding 
aircraft surveillance applications (ASA).\25\
---------------------------------------------------------------------------

    \25\ ASA comprises a number of flight-deck-based aircraft 
surveillance and separation assurance capabilities that may directly 
provide flight crews with surveillance information and alerts.
---------------------------------------------------------------------------

    Several commenters, including AOPA, asserted that the dual-link 
system presents a safety hazard because aircraft equipped with 
different links cannot ``see'' each other on ADS-B In displays in areas 
without ADS-R coverage. The commenters suggested providing ADS-R at all 
public airports where a mix of both systems will be encountered.
    The FAA is deploying ADS-R in all areas where ADS-B ATC 
surveillance exists.\26\ ADS-R collects traffic information broadcast 
on the 978 MHz UAT broadcast link and rebroadcasts the information to 
1090 MHz ES users. Similarly, ADS-R collects traffic information 
provided on the 1090 MHz ES broadcast link and rebroadcasts the 
information to UAT users. ADS-R permits aircraft equipped with either 
1090 MHz ES or UAT to take advantage of ADS-B In applications.
---------------------------------------------------------------------------

    \26\ The service coverage volume for ADS-B In applications is 
explained in greater detail at http://www.adsb.gov.
---------------------------------------------------------------------------

    The FAA disagrees with the comments suggesting that ADS-R 
introduces safety issues because of the added latencies attributed to 
ADS-R processing. ATC automation systems do not require or use ADS-R to 
provide surveillance. The added latency in the rebroadcast of the 
original ADS-B message are measurably small and do not degrade the 
reported NACP, NACV, and NIC values. The ARC 
agreed in its report that the latency in ADS-R processing does not 
degrade the reporting of the position quality parameters.\27\ Latency 
attributed to ADS-R does not compromise the safety of the initial ADS-B 
In applications.
---------------------------------------------------------------------------

    \27\ ADS-B ARC Task II Report to the FAA Appendix N, ADS-R 
Latency and Reliability Expectations (September 26, 2008), available 
on the Web site, http:///www.regulations.gov, FAA-2007-29305-0221.1.
---------------------------------------------------------------------------

    The intended functions of ADS-B, as identified in the NPRM, are not 
compromised by the latency introduced with rebroadcasting the messages. 
However, future ADS-B In applications necessarily may be limited 
becauseof the latency associated with ADS-R.\28\ The FAA has a strong 
interest in providing the option for operators to equip with UAT, so 
they may benefit from FIS-B service. In making the decision to use a 
dual-link strategy, the FAA acknowledged and weighed the fact that 
potential benefits of future applications may not be fully realized 
based on this decision. In situations where an airport is not within 
the planned ADS-B coverage area, the airport will not have ADS-R 
coverage. Consequently, an aircraft with ADS-B In will not have the 
benefit of ADS-R, and ADS-B In will not provide awareness of aircraft 
that are broadcasting on a different broadcast link.
---------------------------------------------------------------------------

    \28\ To date, the requirements for using ADS-B for advanced 
iterations of merging and spacing, and self separation have yet to 
be defined.
---------------------------------------------------------------------------

    If an aircraft leaves the ADS-B coverage area, there will be an 
indication to the pilot that the aircraft is no longer within range of 
ADS-R service. In this case, the pilot needs to maintain separation in 
the same manner done today, which is relying on visual scanning and 
directions from ATC. The FAA will ensure that the dual-link strategy 
does not impact safety as future applications are developed.
3. 1090 MHz Frequency Congestion
    Boeing, Federal Express (FedEx), and IATA suggested that the FAA 
assess future 1090 MHz frequency congestion. The ARC supported the 
dual-link strategy, but recommended that the FAA study the necessary 
mitigations of 1090 MHz frequency congestion. The ARC specifically 
recommended that these mitigations ensure 1090 MHz ES is interoperable 
with ACAS and SSR, while providing sufficient air-to-air range to 
support NextGen ADS-B In applications.
    Congestion on the 1090 MHz frequency is a risk shared by TCAS/ACAS 
and SSR systems using the Mode S transponder. The FAA conducted a study 
to assess 1090 MHz frequency congestion in the future air traffic 
environment.\29\ The FAA is analyzing alternatives and will enact the 
necessary mitigations to reduce the 1090 MHz frequency congestion risk 
for ADS-B, TCAS, and SSR, while enabling ranges appropriate for many 
ADS-B In applications through 2035.
---------------------------------------------------------------------------

    \29\ A copy of this report is available from the Web site http:/
/www.regulations.gov. The docket number for this rulemaking is FAA-
2007-29305.
---------------------------------------------------------------------------

C. Performance Requirements--System

    While some commenters supported the proposed performance 
requirements, numerous organizations and individuals commented that the 
performance requirements generally were too stringent, unnecessary, and 
would entail an undue economic burden on operators.
1. Performance Requirements Tailored to Operator, Airspace, or 
Procedure
    The NPRM proposed specific performance requirements for ADS-B Out. 
Several commenters, including the Aerospace Industries Association of 
America (AIA), Boeing, the DOD, EAA, Honeywell, Lockheed Martin, and 
the ARC, asked the FAA to tailor the ADS-B performance requirements 
based on specific application requirements or airspace.
    Lockheed Martin and the DOD noted that some military aircraft may 
not meet the proposed equipage requirements and would need 
accommodations to operate in ADS-B Out-designated airspace. One 
commenter was concerned that the DOD was exempt from the proposed 
requirements.

[[Page 30169]]

    The FAA has determined that it is not operationally feasible to 
assign different performance requirements dependent on the nature of 
the operation. It would not be effective to require both pilots and 
controllers to verify specific performance parameters before any given 
operation or change of airspace. Therefore, the FAA is specifying 
minimum performance requirements for all ADS-B Out-equipped aircraft to 
operate in certain designated airspace.
    No special allowance is made in this rule to relieve the military 
from the same performance requirements as the civilian aviation 
community. The FAA recognizes that the DOD and other Federal agencies 
are NAS users, and need access to all areas of the NAS today and in the 
future. This rule provides procedures for an aircraft that does not 
meet the ADS-B Out performance requirements, i.e., to obtain an ATC 
authorized deviation to operate in the airspace for which ADS-B is 
required. The FAA will collaborate with the appropriate U.S. Government 
departments or agencies (including but not limited to DOD, and the 
Department of Homeland Security) to develop Memorandums of Agreement to 
accommodate their National defense mission requirements while 
supporting the needs of all other NAS users.
2. Navigation Accuracy Category for Position (NACP)
    The NPRM proposed requiring a NACP greater than or equal 
to 9. This is equivalent to horizontal position accuracy of less than 
30 meters and vertical position accuracy of less than 45 meters. A 
NACP of less than 30 meters horizontal would support ATC 
surveillance, ASSA, FAROA, and other future ADS-B In applications.
    Airbus, ATA, Aviation Communication and Surveillance Systems 
(ACSS), Boeing, Rockwell-Collins, United Airlines, and United Parcel 
Service (UPS) questioned the necessity of a NACP greater 
than or equal to 9. The ARC recommended that the FAA institute 
NACP requirements based on domains of airspace defined by 
different types of operations, with minimum NACP values 
ranging from 5 through 9.\30\ The ARC also recommended that when a 
NACP greater than or equal to 9 is necessary, operators 
should only be required to equip with a position source that could meet 
a NACP greater than or equal to 9 for 95 percent of an hour 
and meet a NACP greater than or equal to 8 for 99.9 percent 
of an hour.
---------------------------------------------------------------------------

    \30\  ADS-B ARC Task II Report to the FAA 6 (September 26, 
2008), available on the Web site, http://www.regulations.gov, FAA-
2007-29305-0221.1.
---------------------------------------------------------------------------

    Boeing commented that there is no need for vertical accuracy 
because neither ATC nor any of the initial ADS-B In applications 
require it. The ARC recommended that the FAA not apply the vertical 
position accuracy requirement associated with a NACP of 9 
for surface operations. The ARC also recommended that the FAA modify 
the definition of a NACP of 9 in DO-260A and DO-282A. This 
modification would remove the vertical accuracy requirement if the 
aircraft is on the surface.
    The FAA reviewed these comments and the necessary requirements for 
the ADS-B Out and ADS-B In applications that are contemplated today. A 
NACP of less than 0.05 NM is required for ATC surveillance. 
A NACP of less than 30 meters is required only for ASSA and 
FAROA. Because surface surveillance benefits enabled by ADS-B will only 
be fully available where Airport Surface Detection Equipment, Model X 
(ASDE-X) systems,\31\ and ADS-R and TIS-B are in use, the FAA has 
reconsidered the universal requirement of a NACP of less 
than 30 meters.
---------------------------------------------------------------------------

    \31\ ASDE-X is a traffic management system for the airport 
surface that provides seamless coverage and aircraft identification 
to air traffic controllers. The system uses a combination of surface 
movement radar and transponder multilateration sensors to display 
aircraft position.
---------------------------------------------------------------------------

    While the higher NACP would support a limited number of 
ADS-B In applications, it could also increase costs \32\ to all 
operators required to meet the ADS-B performance standards. Therefore, 
this final rule reduces the position accuracy reporting requirement and 
adopts a NACP of less than 0.05 NM. This NACP 
requirement applies to all aircraft operating in the airspace 
identified in this rule.
---------------------------------------------------------------------------

    \32\ ADS-B ARC Report to the FAA Appendix P, Programmatic 
Decision Analysis (September 26, 2008), available at http://
www.regulations.gov, FAA-2007-29305-0221.1.
---------------------------------------------------------------------------

    In addition, the FAA considered the comments regarding the vertical 
accuracy component of NACP. As there are no ATC separation 
services requirements for vertical accuracy or integrity, the FAA has 
removed the vertical accuracy and integrity requirement from 
NACP, NACV, NIC, and SIL in TSO-C154c and TSO-
C166b.
3. Navigation Accuracy Category for Velocity (NACV)
    The NPRM proposed requiring a NACV greater than or equal 
to 1, which is equivalent to velocity accuracy of less than 10 meters 
per second.
    The European Organisation for the Safety of Air Navigation 
(EUROCONTROL) commented that a NACV of 1 is not sufficient 
for ATC services or advanced ADS-B In applications. The ARC recommended 
that NACV should not be required.
    Different air navigation service providers may need different 
performance requirements depending on the airspace in which they 
implement ADS-B separation services. The FAA reviewed this requirement 
and concludes that a NACV is required for separation 
services in the United States. The agency modeled and calculated the 
NACV requirements for aircraft separation, using assumptions 
unique to the U.S. environment. Based on this analysis, the FAA 
determined that a horizontal velocity accuracy of less than 10 meters 
per second, as proposed in the NPRM, is required for ATC surveillance 
within the NAS.\33\ Therefore, this requirement is adopted as proposed.
---------------------------------------------------------------------------

    \33\ A copy of the Separation Standards Working Group report is 
available from the Web site http://www.regulations.gov. The docket 
number for this rulemaking is FAA-2007-29305.
---------------------------------------------------------------------------

4. Navigation Integrity Category (NIC)
    The NPRM proposed requiring a NIC greater than or equal to 7, which 
provides navigation integrity of less than 0.2 NM. Boeing questioned 
the necessity of this requirement. The ARC recommended that the FAA 
adopt NIC requirements based on airspace, with minimum NIC values 
ranging from 0 to 7.
    The FAA reviewed this requirement and determined that a NIC of less 
than 0.2 NM is necessary for ATC separation services, particularly in 
the approach environment. Similar to the NACP, it is not 
practical to assign different NIC values based on types of airspace. 
Therefore, this rule requires a NIC of less than 0.2 NM.
5. Surveillance Integrity Level
    The FAA's proposal for surveillance integrity level stated that the 
surveillance integrity level is based on both the design assurance 
level of the ADS-B Out avionics and the position source. Several 
commenters, including Rockwell-Collins, pointed out that the proposed 
definition was inconsistent with the surveillance integrity level 
definition provided in DO-260A. Commenters stated that DO-260A Change 2 
defined surveillance integrity level as including only the position 
source. The ARC recommended that the FAA use the definition of 
surveillance integrity level found in RTCA DO-

[[Page 30170]]

289,\34\ which also limited the design assurance to the position 
source.
---------------------------------------------------------------------------

    \34\ Minimum Aviation System Performance Standards (MASPS) for 
Aircraft Surveillance Applications (ASA).
---------------------------------------------------------------------------

    The FAA asserts that the design assurance of the ADS-B system needs 
to represent the complete system, and not a single piece of that 
system, to provide air traffic separation services. The FAA agrees that 
the inconsistency between the proposed rule and the RTCA standard is 
unworkable; however, RTCA has updated the design assurance requirements 
in DO-260B and DO-282B to include the entire ADS-B avionics system, 
rather than just the position source. The ADS-B system includes ADS-B 
transmission equipment, ADS-B processing equipment, position source, 
and any other equipment that processes the position data transmitted by 
the ADS-B system. The DO-260B change is consistent with the rule.
6. Source Integrity Level (SIL) and System Design Assurance (SDA)
    In DO-260A (TSO-C166a) and DO-282A (TSO-C154b), SIL was defined as 
surveillance integrity level and represented two separate components: 
(1) The maximum probability of exceeding the NIC containment radius and 
(2) a maximum probability of a failure causing false or misleading data 
to be transmitted. DO-260B (TSO-C166b) and DO-282B (TSO-C154c) separate 
these two components into two distinct parameters. SIL is now referred 
to as source integrity level and defines the maximum probability of 
exceeding the NIC containment radius; SDA now defines the maximum 
probability of a failure causing false or misleading data to be 
transmitted.
    The FAA proposed a SIL value of 2 or 3. A SIL of 2, as stated in 
TSO-C166a and TSO-C154b, represented: (1) A maximum probability of 
exceeding the NIC containment radius of 1x10-5 per hour or 
per sample; and (2) a maximum probability of a failure causing false or 
misleading data to be transmitted of 1x10-5 per hour.
    A SIL of 3 represented: (1) A maximum probability of exceeding the 
NIC containment radius of 1x10-7 per hour or per sample and 
(2) a maximum probability of a failure causing false or misleading data 
to be transmitted of 1x10-7 per hour.
    The FAA proposed these two values for SIL because its separation 
standards modeling determined that the probability of exceeding the NIC 
containment radius must be less than 1x10-7 per hour or per 
sample and the probability of a failure causing false or misleading 
data must be less than 1x10-5 per hour. The FAA's TSOs and 
the corresponding RTCA documents did not allow for this combination.
    Therefore, in developing and issuing the NPRM, the FAA assumed that 
most operators, in upgrading their equipment for ADS-B, would equip 
with a global positioning system (GPS) \35\ that would provide a NIC 
containment radius of 1x10-7 per hour (a SIL of 3). However, 
to require the associated maximum probability of failure causing false 
or misleading data to be transmitted at 1x10-7 per hour was 
not only unreasonable but also unnecessary. Therefore, the FAA proposed 
that a SIL of 2 was also acceptable.
---------------------------------------------------------------------------

    \35\ GPS is a U.S. satellite-based radio navigation system that 
provides a global-positioning service.
---------------------------------------------------------------------------

    With the separate SIL and SDA values available under DO-260B and 
DO-282B, the rule requires a maximum probability of exceeding the NIC 
containment radius of 1x10-7 per hour or per sample (which 
equates to a SIL of 3), and a maximum probability of 1x10-5 
per hour of a failure causing false or misleading data to be 
transmitted (which equates to an SDA of 2).
    Changing the proposed probability of exceeding the NIC containment 
radius from 1x10-5 per hour or per sample to 
1x10-7 per hour or per sample should not impact NAS users. 
This is because currently available ADS-B Out systems using GNSS will 
provide an integrity metric based on 1x10-7 per hour.
7. Secondary Position Sources
    The General Aviation Manufacturers Association (GAMA), IATA, and 
Rockwell-Collins commented that the final rule should specify separate 
performance requirements for secondary position sources in the event 
that their primary position source is unavailable.
    The FAA disagrees that a separate set of requirements is necessary 
for secondary position sources because the rule does not require a 
secondary source. The NACP, NACV, NIC, SDA and 
SIL requirements in this rule apply regardless of the position source 
in use.

D. Performance Requirements--Antenna Diversity

    The NPRM proposed that aircraft meet optimum system performance by 
equipping with both a top and a bottom antenna to support ADS-B In 
applications.
    Several commenters, including AOPA, did not support this aspect of 
the proposal because antenna diversity significantly increases the cost 
of ADS-B. AOPA also noted that historical TCAS and transponder use does 
not indicate that dual antennas are necessary.
    Airservices Australia and the Australia Civil Aviation Safety 
Authority noted that Australia is not requiring antenna diversity for 
GA aircraft. The ARC recommended allowing non-diversity antenna 
installations for VFR aircraft flying through Class B and C airspace 
and below 15,000 feet MSL (1090 MHz ES) or below 18,000 feet MSL (UAT), 
but not landing at a primary airport. The ARC also recommended that the 
FAA undertake further studies to assess and validate the need for 
antenna diversity in low-altitude airspace.
    The FAA proposed dual antennas to support ADS-B Out and ADS-B In 
air-to-air applications. For ATC surveillance, only a single bottom-
mounted antenna is necessary. The commenters and the ARC identified 
this element of the proposal as requiring significant costs for the GA 
operators.\36\
---------------------------------------------------------------------------

    \36\ ADS-B ARC Task II Report to the FAA Appendix T, Antenna 
Diversity Comments on Cost, (September 26, 2008), available at 
http://www.regulations.gov, FAA-2007-29305-0221.1.
---------------------------------------------------------------------------

    The FAA has reconsidered its initial strategy for launching the 
ADS-B requirements and is adopting the performance standards necessary 
for ATC surveillance. Therefore, this rule does not require antenna 
diversity for ADS-B to operate in any airspace. This change does not 
alter or affect antenna diversity requirements for other aircraft 
systems, such as transponders or TCAS II.
    Operators should be aware that a dual antenna installation could 
provide additional benefits that are not included in the scope of this 
rule. Airport surface situational awareness or alerting applications 
may be compromised by a single-antenna installation. Operators who 
equip with a single antenna may not be able to accrue all available 
benefits from some or all future ADS-B In applications.
    While requirements for these applications have not yet been fully 
defined, modeling performed by both the ARC and the FAA has indicated 
that a single antenna may not be able to perform adequately for surface 
applications. If the FAA, for example, issues a future mandate 
requiring surface performance capability, operators of single-antenna-
equipped aircraft may need to upgrade the avionics installed on their 
aircraft.
    Operators should also be aware that single-antenna installations 
are not as capable as dual-antenna installations of receiving ADS-B 
messages in an

[[Page 30171]]

environment with a highly congested spectrum. Because of increasing 
congestion on the 1090 MHz frequency over time, single-antenna 
installations of ADS-B may not be able to achieve the same range for 
ADS-B In applications as aircraft with two antennas.
    This limitation on the upper bound of ADS-B In application range 
for single-antenna installations does not impact any of the application 
benefits cited in this rule. The FAA is actively pursuing strategies to 
mitigate spectrum congestion concerns of the 1090 MHz frequency. 
However, operators employing the 1090 MHz ES broadcast link should be 
aware that future air-to-air applications that require longer range 
reception may require dual antennas or a UAT system.

E. Performance Requirements--Transmit Power

    The NPRM proposed that aircraft equipped with UAT would have a 
minimum 16-watt transmit power performance and aircraft equipped with 
1090 MHz ES would have a minimum 125-watt transmit power performance. 
Some commenters, particularly AOPA, argued that the proposal was not 
warranted and imposed unnecessary expense. The ARC commented that using 
the existing power level without antenna diversity may provide the 
performance needed to make broader use of non-diversity antenna 
installations.
    The FAA has determined that reducing the transmit power requirement 
would significantly impact the ground infrastructure. The FAA will rely 
on a series of approximately 800 ground stations to provide ATC 
separation services throughout the United States. The ground stations 
will be placed 150 to 200 miles apart and will require the minimum 
aircraft output power specified in the rule to ensure coverage. 
Lowering the aircraft output power requirements, as suggested by the 
commenters, would require the FAA to expand and redesign the ADS-B 
ground infrastructure. Consequently, the power levels remain unchanged 
in the final rule.

F. Performance Requirements--Total and Uncompensated Latency

    In the NPRM, the FAA proposed to define latency as the time 
information enters the aircraft through the aircraft antenna(s) until 
the time it is transmitted from the aircraft. The FAA further proposed 
that the navigation sensor should process information received by the 
aircraft's antenna(s) and forward this information to the ADS-B 
broadcast link avionics in less than 0.5 seconds. The processed 
information then would be transmitted in the ADS-B message from the 
ADS-B Out broadcast link avionics in less than 1.0 second from the time 
it was received from the navigation sensor.
    Several commenters, including Airbus, Boeing, EUROCONTROL, GAMA, 
and Honeywell, commented that the latency requirements are not well 
defined, are too stringent, and are not consistent with other 
standards.\37\ United Airlines and UPS recommended that the FAA specify 
the accuracy of position information at the time of transmission. 
Boeing and Honeywell recommended that the FAA specify latency, based on 
the time of applicability of the position source.
---------------------------------------------------------------------------

    \37\ The commenters specifically referenced the RTCA Airborne 
Surveillance Applications Minimum Aviation System Performance 
Standards and DO-303 Safety ``Safety, Performance and Inoperability 
Requirements Document of the ADS-B Non-Radar-Airspace (NRA) 
Application.''
---------------------------------------------------------------------------

    The ARC stated that the FAA should: (1) Specify latency 
requirements at the aircraft level, not the equipment level; (2) 
specify the maximum uncompensated latency to minimize or eliminate 
installation wiring changes of existing ADS-B Out implementations, 
while meeting ATC surveillance requirements; (3) specify total latency 
and uncompensated latency; and (4) reference latency to the time of 
applicability of the position provided by the position sensor, rather 
than the time of measurement.
    The FAA adopts three of the four ARC recommendations. First, the 
FAA agrees that latency must be defined at the aircraft level and not 
the equipment level. Second, the latency requirements are set at the 
maximum value that will allow ATC surveillance. Although the latency 
requirements will drive wiring changes in some aircraft, the 
requirements will minimize the number of aircraft affected to the 
maximum extent possible. Third, the FAA has defined the latency 
requirements as total latency and uncompensated latency. The FAA does 
not agree with the fourth recommendation to measure latency at the time 
of applicability. To do so would place latency requirements only on 
part of the overall system and specifically exclude the position source 
latency. Since the entire system's latency, including the position 
source, must be limited to ensure accuracy of the transmitted position 
the rule requires latency to be measured from the position source time 
of measurement and not the time of applicability.
    This rule specifies two separate latency requirements: Total 
latency and uncompensated latency. Total latency is defined as the time 
between when measurements are taken to determine the aircraft's 
geometric position (latitude, longitude, and geometric altitude) and 
when the ADS-B transmitter broadcasts the aircraft's position. Under 
this rule, the total latency cannot exceed 2.0 seconds. Latency is 
compensated to account for the movement of the aircraft while the unit 
is processing the position information. The avionics usually compensate 
latency based on velocity but may also compensate based on 
acceleration.
    Uncompensated latency is defined as the time the avionics does not 
compensate for latency. Under this rule, within the 2.0 second total 
latency allocation, a maximum of 0.6 seconds may be uncompensated 
latency. The avionics must compensate for any latency above 0.6 seconds 
up to the maximum of 2.0 seconds by extrapolating the position to the 
time of transmission.
    Aircraft velocity, as well as position accuracy and integrity 
metrics (NACP, NACV, NIC, SDA, and SIL), must be 
transmitted with their associated position measurement, but are not 
required to be compensated.

G. Performance Requirements--Time To Indicate Accuracy and Integrity 
Changes

    The NPRM proposed that changes in NIC and NACP must be 
broadcast within 10 seconds. This proposed requirement would bind the 
latency of the NIC and NACP, however this requirement would 
also bind the maximum amount of time an integrity fault can exist 
without an indication, as an integrity fault is indicated by changing 
the NIC and NACP to zero.
    The ARC, GAMA, and Rockwell-Collins commented that 10.0 seconds is 
not enough time to indicate a change in the NIC. They specifically 
noted that GNSS position sources use the entire 10-second allocation, 
which does not allow time for the ADS-B equipment to actually transmit 
the change. Rockwell-Collins, GAMA, and the ARC recommended instead 
that changes in NIC and SIL be broadcast within 12.1 seconds.
    Position sources typically provide an accuracy and integrity metric 
with each position that is output. To allow GNSS-based position sources 
time to detect and eliminate possible satellite faults, GNSS systems 
allow the integrity metric associated with a position to actually lag 
behind the output of the position. TSO-C145/146 and TSO-C196 GNSS 
systems have up to 8.0 seconds to alert to an

[[Page 30172]]

integrity fault. TSO-C129 systems do not have an overarching integrity 
fault time-to-alert requirement, but they do have navigation mode 
specific integrity fault time-to-alert requirements. Specifically, TSO-
C129 systems must indicate an integrity fault within 10 seconds in 
terminal and approach modes.
    The requirement to indicate a change in NIC applies to the time 
between when a fault-free NIC is transmitted with a faulted position 
and when the NIC is updated to indicate the fault. Thus, the clock to 
indicate the change in NIC does not start at the onset of the fault, 
but rather at the broadcast of the faulted position from the ADS-B 
system. Thus, the total time to update the NIC is based on the 
cumulative effect of--(1) the position source fault detection and 
exclusion time, and (2) the worst-case asynchronous transmission 
difference between when the fault-free NIC with faulted position is 
transmitted and when the faulted NIC is transmitted.
    The FAA reviewed the separation standards work to determine if a 
12.0 second delay in the broadcast of an integrity fault would impact 
separation standards. The FAA found that no existing terminal and en 
route surveillance standards would be impacted with a 12.0 second 
delay, and thus the rule requires that changes in NIC be broadcast 
within 12.0 seconds.
    The ARC, GAMA, and Rockwell-Collins also commented that changes in 
NACP, NACV, and SIL should be broadcast within 
3.1 seconds versus 10.0 seconds. The FAA determined that there is no 
basis to tighten the requirement. Therefore, the 10.0 second 
requirement applies to indicating changes in NACP, 
NACV, SDA, and SIL.

H. Performance Requirements--Availability

    The FAA did not propose any availability \38\ requirements for this 
rule. The proposed rule generated multiple comments concerning 
statements in the preamble regarding availability and whether the FAA 
should require operators to accomplish a preflight determination of 
GNSS availability. Other commenters focused on a perceived requirement 
for operators to equip with avionics that had a system availability 
equivalent to Wide Area Augmentation System (WAAS) \39\.
---------------------------------------------------------------------------

    \38\ RTCA DO-229, Minimum Operational Performance Standards for 
Global Positioning System/Wide Area Augmentation System Airborne 
Equipment, defines the availability of a navigation system as the 
ability of the system to provide the required function and 
performance at the initiation of the intended operation. 
Availability is an indication of the ability of the system to 
provide usable service with the specified coverage area. Signal 
availability is the percentage of time that navigational signals 
transmitted from external sources are available for use. 
Availability is a function of both the physical characteristics of 
the environment and the technical capabilities of the transmitter 
facilities.
    \39\ WAAS is a U.S. wide-coverage augmentation system to GPS 
that calculates integrity and correction data on the ground and uses 
geostationary satellites to broadcast the data to GPS/SBAS 
(Satellite-Based Augmentation System (non-U.S.)) users.
---------------------------------------------------------------------------

1. Preflight Determination of Availability
    The proposal preamble explained that operators must verify ADS-B 
Out availability before flight as part of their pre-flight 
responsibilities. This is similar to the requirement for preflight 
determination of availability for certain Required Navigation 
Performance (RNP) \40\ operations.
---------------------------------------------------------------------------

    \40\ Required Navigation Performance (RNP) is a statement of the 
total aircraft navigation performance necessary for operation within 
a defined airspace.
---------------------------------------------------------------------------

    ATA argued that the process to determine availability could be time 
consuming for operators and that the FAA should provide further 
justification. Boeing stated that the NPRM did not include an 
availability requirement; therefore, the FAA should correct its 
statement in the NPRM preamble advising operators to make this part of 
their preflight actions.
    The ARC recommended that the FAA provide preflight prediction 
systems that assess the ability of typical positioning sources to meet 
the position accuracy and integrity requirements.
    This rule requires operators to meet the adopted minimum position 
accuracy and integrity performance requirements to operate in the 
airspace described in the rule. To facilitate compliance with the rule 
and assist pilots for the flight planning, the FAA will provide a 
preflight availability prediction service by 2013. Therefore, prior to 
departure, operators should verify that the predicted performance 
requirements will be met for the duration of the flight. This service 
will determine whether GNSS equipment is capable of meeting Sec.  
91.227 position accuracy and integrity requirements for operating in 
the airspace defined in this rule. Operators may also use their own 
preflight availability prediction tools, provided the predictions 
correspond to the performance of their equipment. The FAA advises 
operators to consult manufacturers' information on specific avionics 
and prediction services.
2. System Availability
    Numerous commenters, including the DOD, contended that the proposal 
required WAAS (or implied that the positioning service used by the 
aircraft have an availability equivalent to WAAS.)
    As stated in the NPRM, operators may equip with any position 
source. Although WAAS is not required, at this time it is the only 
positioning service that provides the equivalent availability to radar 
(99.9 percent availability). The FAA expects that future position 
sources such as GNSS using the L5 GPS signal, GPS using Galileo 
signals, and GPS tightly integrated with inertial navigation systems 
will also provide 99.9 percent availability. Operators who equip with 
other position sources, such as non-augmented GPS, may experience 
outages that limit their access to the airspace defined in this rule.
    If an aircraft's avionics meet the requirements of this rule but 
unexpected GPS degradations during flight inhibit the position source 
from providing adequate accuracy (within 0.05 NM) and integrity (within 
0.2 NM), ATC will be alerted via the aircraft's broadcasted data and 
services will be provided to that aircraft using the backup strategy. 
An aircraft that is not equipped to meet the requirements of this rule 
will not have access to the airspace for which ADS-B is required. The 
FAA notes that preflight availability verification eliminates any need 
for the system to meet a specified availability requirement upon 
installation.

I. Performance Requirements--Continuity

    The FAA did not propose a continuity \41\ requirement in the NPRM. 
Several commenters, including Airbus, GAMA, Rockwell-Collins, and the 
ARC, suggested that the FAA add a continuity requirement. These 
commenters argued that such a requirement would ensure that an aircraft 
could continue providing the ADS-B information throughout a flight.
---------------------------------------------------------------------------

    \41\ DO-229 defines the continuity of the system as the ability 
of the total system (comprising all elements necessary to maintain 
aircraft position within the defined airspace) to perform its 
function without interruption during the intended operation. More 
specifically, continuity is the probability that the specified 
system performance will be maintained for the duration of a phase of 
operation (presuming that the system was available at the beginning 
of that phase of operation), and predicted to exist throughout the 
operation.
---------------------------------------------------------------------------

    Aircraft are to meet the performance requirements for the duration 
of the operation, not just a portion of the flight. The FAA's preflight 
availability prediction service will help pilots ensure that the 
aircraft can continue transmitting ADS-B information throughout their 
planned flight, based on expected operations. Unexpected

[[Page 30173]]

failures will be accommodated, as described in the discussion on 
availability; therefore, there is no need for a separate continuity 
requirement.

J. Performance Requirements--Traffic Information Service--Broadcast 
Integrity (TIS-B)

    The NPRM did not propose any changes to the standards for TIS-B. 
Boeing stated that the FAA's plans to implement TIS-B with a SIL of 0 
would severely limit its utility for ADS-B In applications. Boeing 
recommended that the FAA change TIS-B to provide a SIL of 2 or greater, 
to be consistent with the SIL proposed for ADS-B Out. Honeywell 
commented that a TIS-B integrity level should be established for value-
added, near-term applications. The ARC did not specifically comment on 
the TIS-B SIL, but did recommend that the FAA include a discussion of 
the FIS-B and TIS-B benefits in the preamble to the ADS-B Out final 
rule.
    The TIS-B system is expected to support four of the five initial 
ADS-B In applications. The FAA acknowledges that future ADS-B In 
applications may require improved representation of the position 
integrity metrics. With the SIL and SDA changes incorporated in DO-260B 
and DO-282B and possible changes to future versions of DO-317, the FAA 
plans, outside of this rulemaking effort, to evaluate the usefulness of 
the broadcast of integrity parameters from TIS-B.

K. Broadcast Message Elements

1. NACP/NACV/NIC/SDA/SIL
    The NPRM did not specifically propose NACP, 
NACV, NIC, or SIL as broadcast message elements in section 4 
of appendix H to part 91, Minimum Broadcast Message Element Set for 
ADS-B Out. These requirements were specified in section 3 of appendix H 
to part 91, ADS-B Out Performance Requirements for NIC, NAC, and SIL.
    Honeywell noted that NACP, NACV, NIC, and SIL 
are required message elements in DO-260A.
    To resolve any questions, the FAA has repeated the indications for 
these elements in Sec.  91.227(d)(16) through (19). In addition, and 
consistent with TSO-C166b and TSO-C154c, SIL and SDA are listed as 
separate values.
2. Receiving ATC Services
    The NPRM proposed requiring the message element ``Receiving ATC 
Services.'' Several commenters, including ACSS, Airbus, Boeing, 
EUROCONTROL, United Airlines, and UPS, commented that this message 
element is unnecessary and poorly defined. UPS and United Airlines 
suggested that the FAA use the ground automation system to accomplish 
the function of this message element. Some commenters also contended 
that this message element could require an additional user interface, 
which is not available on current equipment.
    The ARC recommended that the FAA clarify the definition of this 
message element and explain how it can be implemented without pilot 
entry. The ARC also requested that the FAA research whether both 
``Receiving ATC Services'' and ``Mode 3/A Code'' are necessary.
    The FAA concludes that ``Receiving ATC Services'' is not necessary 
for ATC surveillance because this information can be directly inferred 
from the Mode 3/A code. Furthermore, this message element could 
increase costs for an additional user interface. Therefore, this rule 
does not include ``Receiving ATC Services'' as a required broadcast 
message element.
3. Length and Width of the Aircraft
    The NPRM proposed requiring a message element to broadcast the 
length and width of the aircraft.
    Airbus and EUROCONTROL commented that length and width information 
is not necessary for surveillance or airborne ADS-B Out applications. 
Airbus and an individual commenter noted that length and width 
information should be quantified relative to the aircraft position 
reference point or to a known offset.
    GAMA and Rockwell-Collins noted that the TSOs allow some aircraft 
to continuously transmit ``in-air'' because these aircraft do not have 
a means to determine their air/ground status. Rockwell-Collins 
commented that the rule should require all aircraft to assess their 
air/ground status and broadcast the appropriate set of messages for 
that status. The ARC recommended that the FAA address this issue in the 
preamble to the final rule.
    The FAA notes that TSO-C154c and TSO-C166b allow the operator to 
determine whether to transmit the aircraft's latitude and longitude 
referenced to the GPS antenna location or the ADS-B position reference 
point. The ADS-B position reference point is the center of a box, based 
on the aircraft length and width. With the position offset to the ADS-B 
reference point, the ADS-B is able to report the position of the edges 
of the aircraft. This rule does not require operators to apply the 
position offset because ATC surveillance does not require a position 
offset.
    The FAA concludes that the requirement to transmit aircraft length 
and width is necessary because this message element will be used as an 
input for ASDE-X systems and allows the FAA to decommission ASDE-3 
radars \42\ that interface with ASDE-X, as well as the surface movement 
radar systems that are at certain ASDE-X sites without ASDE-3. The 
length-width code will be preset when ADS-B equipment, meeting the 
standards in TSO-C154c or TSO-C166b, is installed in the aircraft.
---------------------------------------------------------------------------

    \42\ ASDE-3 is an airport radar that shows to tower controllers 
the location of aircraft on the surface.
---------------------------------------------------------------------------

    ADS-B equipment transmits an airborne position message when the 
aircraft is airborne, and a surface position message when the aircraft 
is on the ground. Aircraft automatically determine airborne or ground 
status and transmit the appropriate message. For aircraft that are 
unable to determine their air-ground status automatically, the RTCA 
standards and TSOs allow the aircraft to continuously transmit the 
airborne position message. However, the length width code is a required 
message element in this rule, and is only transmitted in the surface 
position message. Thus, to comply with the rule, the aircraft must 
automatically determine its air-ground status and transmit the surface 
position message which includes the length width code when on the 
ground.
4. Indication of the Aircraft's Barometric Pressure Altitude
    The NPRM proposed a broadcast message that would report the 
aircraft's barometric pressure altitude. Several commenters, including 
the ARC, GAMA, Rockwell-Collins, Sandia National Laboratories (SANDIA), 
and UPS, identified an inconsistency regarding the barometric altitude 
message element between the proposed rule's preamble and regulatory 
text.
    The FAA agrees that the NPRM preamble was not completely clear and 
should have better reflected the proposed regulatory text. The proposed 
regulatory text stated that the pressure altitude reported for ADS-B 
Out and Mode C/S transponder is derived from the same source for 
aircraft equipped with both a transponder and ADS-B Out. The FAA 
confirms that the barometric altitude reported from the aircraft's 
transponder and ADS-B Out must be derived from the same source.
    In addition, the FAA is striking the January 1, 2020 compliance 
date from proposed Sec.  91.217(b). If an operator chooses to use ADS-B 
before January 1,

[[Page 30174]]

2020, the operator must meet the provisions of that section.
5. Indication of the Aircraft's Velocity
    The NPRM proposed a message element that would provide ATC with 
information about the aircraft's velocity and direction. However, the 
NPRM preamble mistakenly referred to velocity as airspeed. Several 
commenters, including Airbus, the ARC, Rockwell-Collins, SANDIA, and 
UPS, recommended that the message element reflect velocity instead of 
airspeed. Rockwell-Collins noted that velocity could be derived from 
other sources, including an inertial navigation system. ACSS, United 
Airlines, and UPS recommended that the FAA require the velocity source 
for ADS-B transmissions to be the most accurate velocity source on the 
aircraft. The ARC recommended that the issue of velocity source be 
referred to RTCA.
    This message element will provide ATC with the aircraft's velocity, 
as well as a clearly stated direction and description of the rate at 
which an aircraft changes its position. The velocity must be 
transmitted with a NACV of less than 10 meters per second. 
Any velocity source that meets these requirements will comply with this 
rule. The FAA referred the question on velocity source to RTCA for 
further review, as the ARC recommended. RTCA determined that the 
velocity source must be the same source that provides the aircraft's 
position, and included this requirement in DO-260B and DO-282B.
6. Indication If Traffic Alert and Collision Avoidance System II or 
Airborne Collision Avoidance System Is Installed and Operating in a 
Mode That May Generate Resolution Advisory Alerts
    The NPRM proposed requiring a message element that would (1) 
identify to ATC whether the aircraft is equipped with TCAS II or ACAS 
and (2) identify whether the equipment is operating in a mode that 
could generate resolution advisory alerts. Airbus asked for more 
information on why this message element is required. EUROCONTROL 
commented that this message element should be internationally 
harmonized before the FAA adopts this requirement. UPS asked whether 
this message should be indicated if the TCAS II is operated in the 
traffic advisory mode. The ARC sought to retain this message element, 
but asked the FAA to clarify its intended use in the final rule.
    The TCAS installed and operating in a mode that can generate a 
resolution advisory message will be used by the FAA to monitor in-
service performance to address NAS inefficiencies and take appropriate 
corrective actions. This information may also be used to support future 
ADS-B In applications. This message element was harmonized with the 
international community in the development of DO-260B and ED-102A.\43\
---------------------------------------------------------------------------

    \43\ EUROCAE MOPS for 1090 MHz Automatic Dependent Surveillance-
Broadcast (ADS-B).
---------------------------------------------------------------------------

7. For Aircraft With an Operable Traffic Alert and Collision Avoidance 
System II or Airborne Collision Avoidance System, Indication If a 
Resolution Advisory Is in Progress
    The NPRM proposed a message element to indicate that a resolution 
advisory is in progress. EUROCONTROL recommended that the FAA 
internationally harmonize this message element before adopting the 
requirement. Airbus noted that this element may be achieved with DO-
260A.
    Similar to the discussion in II.K.6. above, the message that a TCAS 
resolution advisory is in progress will be used by the FAA to monitor 
in-service performance to address NAS inefficiencies and take 
appropriate corrective actions. This information may also be used to 
support future ADS-B In applications. This message element was 
harmonized with the international community in the development of DO-
260B and ED-102A.
8. Indication of the Mode 3/A Transponder Code Specified by ATC 
(Requires Flightcrew Entry)
    The NPRM proposed a message element to transmit the aircraft's 
assigned Mode 3/A transponder code.
    Several commenters, including ACSS, Boeing, SANDIA, and UPS, argued 
that this message element should not be necessary with ADS-B 
surveillance, and suggested deleting the requirement. GAMA expressed 
concern that different codes in the Mode 3/A transponder and the ADS-B 
could result in an indication of a traffic conflict. GAMA specifically 
recommended a one code entry or revising the automation to resolve 
conflicting information. Airbus and the ARC supported this message 
element requirement and the ARC requested more information on its 
intended use.
    The FAA has determined that the same ATC-assigned Mode 3/A code 
must be transmitted by both the transponder and the ADS-B Out message. 
If the code transmitted by ADS-B differs from the Mode 3/A code 
transmitted by the transponder, it could result in duplicative codes or 
inaccurate reporting of aircraft position. If the aircraft's avionics 
are not capable of allowing a single point of entry for the transponder 
and ADS-B Out Mode 3/A code, the pilot must ensure that conflicting 
codes are not transmitted to ATC.
    ATC uses the Mode 3/A code to identify aircraft that are under 
surveillance and possibly under ATC direction. This identifier is 
necessary to issue directions to specific aircraft about nearby air 
traffic. The Mode 3/A code and the International Civil Aviation 
Organization (ICAO) 24-bit address are duplicative for some functions. 
This duplication is necessary because many current ATC automation 
systems are not yet capable of using the ICAO 24-bit address. 
Therefore, the FAA retains this message element in the rule.
9. Indication of the Aircraft's Call Sign That Is Submitted on the 
Flight Plan, or the Aircraft's Registration Number (Aircraft Call Sign 
Requires Flightcrew Entry)
    The NPRM proposed a requirement for this message element to 
indicate either the aircraft's call sign (as submitted on its flight 
plan), or the aircraft's registration number. An individual commenter 
disagreed with the required broadcast message element for aircraft 
identity and noted that it uses unnecessary bandwidth.
    This message element correlates flight plan information with the 
data that ATC views on the radar display, and facilitates ATC 
communication with the aircraft. This message element also will support 
certain ADS-B In applications such as enhanced visual approach.
    In the final rule, the regulatory text is amended to provide that 
an operator does not need to populate the call sign/aircraft 
registration field for a UAT equipped aircraft if he or she has not 
filed a flight plan, is not requesting ATC services, and is using a UAT 
self-assigned temporary 24-bit address. Although the FAA does not 
prohibit the anonymity feature, operators using the anonymity feature 
will not be eligible to receive ATC services, may not be able to 
benefit from enhanced ADS-B search and rescue capabilities, and may 
impact ADS-B In situational awareness benefits.
10. Indication If the Flightcrew Has Identified an Emergency, Radio 
Communication Failure, or Unlawful Interference (Requires Flightcrew 
Entry)
    The NPRM proposed this message element to alert ATC that an 
aircraft is experiencing emergency conditions. Airbus asked the FAA to 
clarify which emergency/priority codes are required.

[[Page 30175]]

The ARC recommended that the FAA explain in the final rule the 
emergency status requirement and describe how it will be used.
    This message element alerts ATC that the aircraft is experiencing 
emergency conditions and indicates the type of emergency. Both TSO-
C154c and TSO-C166b identify six unique emergency codes. All emergency 
codes may be transmitted. Under this rule, only emergency, radio 
communication failure, and unlawful interference are required. This 
information will alert ATC to potential danger to the aircraft so it 
can take appropriate action. Message elements for minimum fuel, downed 
aircraft, and medical emergency are not required by this rule.\44\ ADS-
B equipment may automatically set these required emergency conditions 
based on the Mode 3/A code.
---------------------------------------------------------------------------

    \44\ Mode A codes 7700, 7600, and 7500 currently are reserved 
for these emergencies. See Annex 10 to the Convention on 
International Civil Aviation Aeronautical Telecommunications, Volume 
4, Surveillance and Collision Avoidance Systems, 4th Edition, July 
2007.
---------------------------------------------------------------------------

11. Indication of the Aircraft's ``IDENT'' to ATC (Requires Flightcrew 
Entry)
    The NPRM proposed this message element to help controllers quickly 
identify a specific aircraft. United Airlines and UPS commented that 
they believe controllers use the ``IDENT'' function to attain aircraft 
identification information. They noted that future identification 
systems should include aircraft information; therefore, they believed 
this element is not necessary. FreeFlight commented that ``IDENT'' 
should be retained. The ARC recommended that the FAA clarify how the 
``IDENT'' requirement will be used.
    The ``IDENT'' function is used regularly in current ATC operations 
to help controllers quickly identify a specific aircraft. The ``IDENT'' 
feature also allows ATC to quickly identify aircraft that have entered 
incorrect flight identification or Mode 3/A codes. The FAA is adopting 
this message element in this rule.
12. Indication of the Emitter Category
    The NPRM proposed requiring a message element for an aircraft's 
emitter category.
    EUROCONTROL questioned the business case behind this requirement. 
UPS asked that the FAA better define the emitter categorizations in the 
final rule.
    This message element is necessary for ATC separation services and 
wake turbulence separation requirements. TSO-C166b and TSO-C154c 
provide a list and description of the different emitter categories. 
Emitter category is set during installation of the ADS-B avionics in 
the aircraft and will not change over time.
13. Indication Whether an ADS-B In Capability Is Installed
    The NPRM proposed this message element to indicate to ATC whether a 
cockpit display of traffic information (CDTI) \45\ is installed and 
operational. Several commenters, including Boeing, EUROCONTROL, and 
SANDIA, commented that this message element was poorly defined, 
difficult and expensive to implement, and of little value to ADS-B In 
applications and ATC surveillance. UPS asked whether a message is 
required when a CDTI is installed but not operating. The ARC 
recommended that the FAA clarify the use of this data element.
---------------------------------------------------------------------------

    \45\ CDTI is a generic display that provides a flight crew with 
traffic surveillance information about other aircraft, surface 
vehicles, and obstacles, including their identification, position, 
and other message set parameters. CDTI information would commonly be 
displayed on a Multifunction Display (MFD).
---------------------------------------------------------------------------

    RTCA updated the definition of this message element in DO-260B and 
DO-282B. The FAA adopted these updates in TSO-C166b and TSO-C154c. This 
message element now indicates which aircraft are capable of receiving 
ADS-B In services and therefore require TIS-B and ADS-R transmissions 
from the ground. Under the new definition, this message element now 
indicates whether an ADS-B In capability is installed in the aircraft, 
but does not require a report of operational status.
14. Indication of the Aircraft's Geometric Altitude
    The NPRM proposed a message element indicating the aircraft's 
geometric altitude.
    Several commenters, including Airbus, Boeing, Dassault, the 
European Business Aviation Association (EBAA), EUROCONTROL, Honeywell, 
and Rockwell-Collins, commented on the proposed requirement. Most of 
the commenters questioned this message element and stated that neither 
ATC surveillance nor ADS-B In require geometric altitude. Dassault, 
EBAA, EUROCONTROL, and Honeywell supported this message element. The 
ARC recommended that the FAA justify the need for this message element.
    Geometric altitude is the height of the aircraft above the World 
Geodetic System 84 ellipsoid, which is a scientific approximation of 
the earth's surface. This message element will be used within the ADS-B 
ground system to confirm accuracy and identify discrepancies between 
geometric altitude and barometric altitude. Additionally, the FAA will 
integrate this comparison function into a continuing airworthiness 
monitoring function.

L. Ability To Turn Off ADS-B Out Transmissions

    The NPRM proposed requiring a pilot to turn off ADS-B equipment if 
directed by ATC, for example, if the ADS-B unit was broadcasting 
erroneous information.
    The ARC, Boeing, United Airlines, and UPS recommended eliminating 
the requirement to turn off ADS-B Out transmissions. A few commenters, 
including British Airways, were concerned that being able to turn off 
ADS-B Out, while keeping the transponder on, could require additional 
design changes and increase costs because most existing equipment is 
not capable of operating in this manner. Boeing stated that eliminating 
erroneous ADS-B transmissions could be accomplished by turning the 
transponder off or having a capability within the ground system to 
allow the controller to manually remove selected targets. Rockwell-
Collins recommended that the FAA require the ADS-B equipment to detect 
failures and disable ADS-B Out transmissions of erroneous data.
    The FAA modified the ground automation system to be able to exclude 
incorrect ADS-B data. With this enhancement to the automation, the 
aircraft does not need to have a capability for a pilot to disable ADS-
B transmissions. Therefore, the final rule does not require the pilot 
to be able to turn off ADS-B Out transmissions.

M. Existing Equipment Requirements

1. Transponder Requirement
    The NPRM specified that the proposal for ADS-B equipage would not 
alter existing transponder regulations.
    Several organizations and individuals, including AOPA, opposed 
adding ADS-B Out performance requirements without removing the 
transponder requirement. ATA and Boeing requested that the FAA make a 
commitment to remove transponders. Several organizations and 
individuals further commented that the FAA should pursue an ADS-B based 
collision-avoidance system and reconsider the backup strategy, which is 
based on secondary surveillance systems. ALPA supported the FAA's plan 
to retain transponders.
    The ARC made multiple recommendations associated with

[[Page 30176]]

transponder removal: (1) The ADS-B implementation strategy should 
include the removal of transponders from low-altitude aircraft without 
an ACAS; (2) the FAA should commit to a strategy for achieving 
transponder removal from low-altitude domestic aircraft; and (3) the 
FAA should study whether ACAS can be modified to use ADS-B as the 
primary surveillance data for collision avoidance, as well as what ACAS 
upgrades are required to support NextGen.
    Removing the transponder requirement would involve substantial 
changes to the ADS-B backup strategy and TCAS II/ACAS, which are 
outside the scope of this rulemaking. Transponders will still be 
required when the backup surveillance strategy using SSR is necessary 
and to interact with TCAS- and ACAS-equipped aircraft. Separate from 
this rulemaking, the FAA may consider (in coordination with the 
appropriate surveillance and NextGen planning organizations), whether 
transponders could eventually be removed and, if so, what steps are 
necessary to accomplish this.
2. Emergency Locator Transmitter Requirement
    The NPRM did not propose any changes to the emergency locator 
transmitter (ELT) \46\ requirements.
---------------------------------------------------------------------------

    \46\ An ELT is an electronic battery-operated transmitter 
developed as a means of locating downed aircraft.
---------------------------------------------------------------------------

    Several commenters, including ATA and the National Business 
Aviation Association (NBAA), argued that ADS-B should be used instead 
of an ELT, and that ELT requirements could be included in this rule. 
AOPA also recommended a long-term strategy to include ELT removal, and 
stated that ADS-B could enhance current search-and-rescue procedures to 
increase the number of successful rescues.
    The ARC recommended that the FAA explore whether an ADS-B tracking 
service also could be used for search and rescue to aid in crash 
locating. The ARC also recommended that the FAA conduct a study 
considering an ADS-B-based search-and-rescue solution that would enable 
removal of 121.5 MHz ELTs for certain domestic operations.
    The FAA has determined that the ADS-B system currently cannot 
replace the ELT function. The ADS-B system is not required to be 
crashworthy and, thus, may not be operable or able to transmit 
following an aircraft accident. Additionally, current search-and-rescue 
technology is not compatible with ADS-B operations because ELTs 
broadcast on 121.5 or 406 MHz (not 1090 or 978 MHz). The FAA recognizes 
the value of a ground application that could allow for timely and 
accurate flight tracking of downed aircraft and is evaluating this 
capability separate from this rulemaking.
    The FAA considered the ARC recommendation to evaluate the 
feasibility of replacing the ELT with the ADS-B system. However, the 
FAA has determined that ADS-B is not a feasible replacement for the 
ELT, as discussed above; therefore, the FAA does not plan to undertake 
such a study at this time.

N. Program Implementation

1. Timeline
    The FAA proposed that all aircraft operating in the airspace areas 
specified in the rule meet the performance requirements by January 1, 
2020.
    The majority of commenters recommended various options for the 
implementation of ADS-B, including the discontinuation of secondary 
and/or primary radar systems once ADS-B is operational NAS-wide. Some 
commenters, including AIA and AOPA, requested that the FAA provide 
certain basic levels of ADS-B service for several years before the ADS-
B compliance date.
    Several commenters, including ALPA and the National Transportation 
Safety Board (NTSB), suggested that the compliance date or service 
provision of ADS-B occur sooner than 2020, to obtain benefits more 
quickly. United Airlines recommended a 2015 compliance date for 
operations above FL 240. The Cargo Airline Association (CAA) 
recommended lower performance requirements for a 2015 compliance date. 
Several commenters, including the Aircraft Electronics Association, 
FedEx, and the National Air Carriers Association, suggested extending 
or adding flexibility to the 2020 compliance date.
    Numerous commenters, including ATA, Boeing, IATA, and Rockwell-
Collins, suggested a two-phased implementation strategy. The first 
phase would use existing equipment, avionics standards, and 
capabilities, which would allow industry and the FAA to demonstrate, 
validate, and evaluate ADS-B applications. After operational experience 
in the first phase was sufficient to generate the appropriate 
standards, the second phase would establish a mandate for ADS-B Out 
performance standards. Some commenters suggested that the second phase 
be a combined ADS-B In and ADS-B Out rule.
    The ARC endorsed the proposed 2020 compliance date, but recommended 
that the FAA allow operators to use existing equipage to accrue early 
benefits. Specifically, the ARC recommended that the FAA: (1) Take 
advantage of existing 1090 MHz ES-equipped aircraft and allow their 
operation in the Gulf of Mexico for non-radar airspace and (2) 
transition to a fully functional ADS-B Out capability enabled by DO-
260B,\47\ to allow access to the additional applications and services 
for ADS-B In. The ARC also recommended that the FAA adopt the European 
Aviation Safety Agency (EASA) Acceptable Means of Compliance 20-24 
(permitting the use of early DO-260 avionics for separation) in non-
radar airspace, with appropriate measures to ensure ADS-B integrity.
---------------------------------------------------------------------------

    \47\ The ARC recommended DO-260A Change 3, which is DO-260B.
---------------------------------------------------------------------------

    After reviewing all the comments, the FAA finds that a 2020 
compliance date remains appropriate because NAS users need time to 
equip to the requirements of the rule. Most air carriers can use 
regularly scheduled maintenance to install or upgrade their equipment. 
The FAA also expects that this timeframe will provide sufficient 
operational experience to make ADS-B the primary source for 
surveillance in 2020.
    FIS-B and TIS-B services are already available in several areas of 
the country for ADS-B In-equipped aircraft and will continue as an 
integral part of the implementation of the ADS-B ground infrastructure. 
NAS-wide ground infrastructure implementation is scheduled to be 
complete in 2013, which would provide operators with at least 7 years 
of operational experience with these services before the ADS-B 
compliance date of 2020.
    The FAA examined whether it is operationally feasible and 
economically beneficial to use DO-260 avionics in radar and non-radar 
airspace before 2020. From an operational perspective, the FAA found 
that the existing DO-260 equipment does not meet the surveillance needs 
for ATC in the United States for various reasons: (1) DO-260 avionics 
do not independently report the accuracy and integrity metrics; (2) DO-
260 avionics allow the integrity metric to be populated with accuracy 
information during integrity outages, which is unacceptable for 
aircraft separation services; (3) DO-260 avionics do not include a 
message element for Mode 3/A code, which is necessary for aircraft 
surveillance; and (4) the majority of existing DO-260 installations 
were accomplished on a noninterference basis under the transponder 
approval guidelines. (This certification verifies that the equipment

[[Page 30177]]

is safe onboard the aircraft, but does not issue any approval that 
would permit its use for ADS-B operations.)
    Therefore, the FAA concluded that without upgrades to the 
equipment, the use of DO-260 avionics will not meet the surveillance 
needs in the NAS. Furthermore, without appropriate integrity 
monitoring, DO-260 avionics cannot be used for separation of aircraft. 
Its utility would be limited to potentially reducing separation in non-
radar areas, or increasing efficiency in radar airspace through more 
timely updates of information.
    Further analysis addressed whether existing DO-260 avionics could 
be beneficial to provide separation services in the Gulf of Mexico, or 
to provide efficiency benefits through improved performance of User 
Request Evaluation Tool (URET) \48\ and Traffic Management Advisor 
(TMA).
---------------------------------------------------------------------------

    \48\ URET is an air traffic control tool that assists 
controllers with timely detection and resolution of predicted air 
traffic problems.
---------------------------------------------------------------------------

    To use DO-260 avionics in the Gulf of Mexico, the FAA estimated it 
would incur approximately $4 million in costs to upgrade the 
automation; would need to provide additional ground stations and 
receiver autonomous integrity monitoring (RAIM) predictions; would need 
to develop procedures; and would need to address aircraft certification 
issues.\49\ Comparatively, the FAA concluded that benefits from this 
action would only recover approximately 70 percent of the costs.
---------------------------------------------------------------------------

    \49\ A copy of the DO-260 Business Case Analysis is available 
from the Web site http://www.regulations.gov. The docket number for 
this rulemaking is FAA-2007-29305.
---------------------------------------------------------------------------

    The costs associated with using existing DO-260 avionics relative 
to improved performance of URET and TMA were estimated at $31 million 
and the estimated benefit in performance was $72 million. While this 
analysis indicated that the benefits of improved URET and TMA 
performance outweigh the costs of accommodating DO-260 equipped 
aircraft,\50\ the FAA found that it raised some policy concerns.
---------------------------------------------------------------------------

    \50\ The analysis concluded that it was not cost-beneficial to 
use DO-260 avionics in the Gulf of Mexico prior to 2020.
---------------------------------------------------------------------------

    First, the FAA does not expect to have the full NAS-wide ADS-B 
infrastructure completed for this effort until 2013. As the ADS-B rule 
would go into effect in 2020, any benefits accrued through the use of 
DO-260 avionics would only be available for approximately 7 years. 
Operators would be required to make a second investment in avionics to 
comply with the rule in 2020.
    Second, a collection of broadcast samples indicated that there is a 
wide variety of equipage among current DO-260 users. Although 
approximately 7,500 aircraft in the United States transmit some ADS-B 
data that would conform to DO-260, only about 1,500 aircraft transmit 
enough data to be useful for 5 NM separation in the Gulf of Mexico and 
input into ATC decision support tools (URET and TMA).\51\ Many DO-260 
operators would require some upgrade costs to bring their existing 
systems into compliance with a unified standard; these would be in 
addition to the costs incurred for taking aircraft out of service for 
certification. Although the user costs were not thoroughly assessed by 
the ARC, the FAA estimated the costs at $15,000 per aircraft.\52\
---------------------------------------------------------------------------

    \51\ A copy of the Honeywell Technology Solutions Inc. DO-260 
study is available from the Web site http://www.regulations.gov. The 
docket number for this rulemaking is FAA-2007-29305.
    \52\ The DO-260 Business Case Analysis assumed the cost of 
$15,000 to upgrade an aircraft equipped with DO-260 only. The cost 
does not include all costs to meet the rule. The cost was used for 
the DO-260 Business Case Analysis and not used in the Regulatory 
Impact Analysis.
---------------------------------------------------------------------------

    Given the above, the FAA could not justify the proliferation of 
avionics for the short-term that would not be compliant with the final 
rule in 2020. Therefore, the agency concluded that the public interest 
was not best served by using DO-260 avionics for ADS-B applications in 
radar and non-radar airspace before 2020.
2. Financial and Operational Incentives
    Numerous commenters, including AIA, the ARC, and NBAA, recommended 
a variety of financial and operational incentives to make ADS-B more 
cost-beneficial for the end user. Some commenters specifically 
recommended that the FAA offer additional incentives for operators who 
adopt early. NBAA recommended accelerated operational benefits to 
encourage early installation of ADS-B equipment. Several commenters 
stated that without operational incentives, aircraft operators with 
legacy equipment will delay upgrades until the mandated compliance 
date.
    AOPA and the Helicopter Association International (HAI) recommended 
several operational improvements and safety enhancements for ADS-B, 
including: (1) Flight following and radar services at lower altitudes, 
(2) terminal ATC services at GA airports, (3) automatic instrument 
flight plan closure, (4) instrument flight rules (IFR) low altitude 
direct routing, (5) enhanced flight service information, and (6) 
improved real time weather. HAI also recommended that the FAA install 
ground stations near hospitals and trauma centers to maximize benefits 
for the emergency medical services community and encourage ADS-B 
equipage.
    ATA, CAA, the National Air Transportation Association, NBAA, and 
UPS recommended specific operational incentives for early equipage, 
including: (1) Implementing ADS-B in under-used areas of the NAS, (2) 
providing preferential access to congested airspace, (3) deploying the 
necessary ADS-B infrastructure for traffic crossing the Gulf of Mexico, 
and (4) providing services for on-demand operators at small community 
airports.
    Some commenters, including AOPA, HAI, and CAA, recommended 
financial incentives or tax credits for ADS-B equipage.
    The following activities are scheduled to be complete by 2013:
     Ground infrastructure coverage needed for the mandated 
airspace,\53\
---------------------------------------------------------------------------

    \53\ The planned ADS-B service coverage is explained in greater 
detail at http://www.adsb. gov/.
---------------------------------------------------------------------------

     ADS-B interface to automation systems,
     Guidelines for equipment certification,
     Operations Specifications approval,
     Approval to use ADS-B to meet established separation 
standards,
     ATC operational procedures for non-radar airspace that has 
ADS-B coverage, and
     FAA controller training and procedures.
    The ADS-B program is currently funded and designed to provide 
services in parts of Alaska, the Gulf of Mexico, and areas in the NAS 
where radar coverage currently exists. Additionally, actual ADS-B 
coverage may exceed the defined radar coverage at lower altitudes in 
some areas. The FAA cannot assess, however, the extent of this coverage 
or its potential use for the ADS-B service until the ADS-B 
implementation is complete in 2013.
    The FAA acknowledges that the ADS-B system could be improved by 
expanding the surveillance coverage of ADS-B to non-radar airspace. The 
improved accuracy and update rate afforded by ADS-B provides the 
ability to improve future NAS operations. As the number of projected 
flight operations continues to increase, efficiency improvements to the 
NAS are critical to addressing new demands. Therefore, the FAA will 
continue to explore opportunities to use the ADS-B infrastructure to 
provide additional coverage in non-radar areas. The FAA also notes that 
ADS-B implementation will not affect flight following services in 
effect today.

[[Page 30178]]

    The FAA is actively pursuing agreements with airlines, avionics 
manufacturers, airports, and other NAS users to encourage early 
equipage of ADS-B. These agreements incorporate a variety of items, 
including: (1) The possibility of developing preferred routes and cost 
sharing for avionics in testing new applications, and (2) early 
equipage and experience with advanced ADS-B applications that are not 
available to non-equipped aircraft.
    The FAA currently has several agreements with airlines and state 
entities specifying that the FAA may enable benefits in exchange for 
early ADS-B equipage. Additionally, the FAA, HAI, and oil platform 
owners have an agreement for the Gulf of Mexico by which the FAA is 
providing communication, navigation, and surveillance for ADS-B-
equipped helicopter operators.
    The FAA and UPS have an agreement for testing and developing 
merging and spacing, CDTI/Multi Function Display Assisted Visual 
Separation (CAVS), and surface situational awareness applications in an 
environment that provides measurable benefits. Additionally, the FAA is 
working with Honeywell and ACSS to accelerate ASSA, FAROA, and surface 
indication and alerting applications.
    The FAA is working with US Airways to develop a work plan for 
implementing ADS-B/NextGen technologies and procedures in parts of the 
East Coast as a prelude to national implementation. In addition, the 
FAA has an agreement with United Airlines to expedite oceanic in-trail 
procedures development. The FAA is also working with NetJets on several 
NextGen initiatives for performance-based navigation, communication, 
and surveillance applications.
    The FAA has established an ADS-B compatible Wide Area 
Multilateration system in the mountainous areas of Colorado pursuant to 
an agreement with the Colorado Department of Transportation. The FAA 
continues to examine different areas of the country to determine 
opportunities for surveillance service expansion and is continuing to 
work with various state aviation offices.
    In addition, the FAA continues to examine opportunities to provide 
ADS-B services in areas that would benefit from increased surveillance. 
The FAA does not currently have a list of airports that are targets for 
ADS-B expansion. However, the FAA has started to identify areas that 
would benefit most from ADS-B services. The FAA encourages cities, 
states, airports, and private interests (such as hospitals and trauma 
centers) to help determine surveillance needs and opportunities.
    ADS-B can provide surveillance at lower altitudes than radar. 
Moreover, ADS-B infrastructure is more easily deployed than most radar 
in remote and hard-to-reach areas. The flexibility associated with 
implementing ADS-B can facilitate service by helicopters to certain 
communities. Deployment of ADS-B systems on medical, police, or tourist 
helicopters could provide a level of asset tracking and search-and-
rescue capability that would be difficult to replicate with existing 
surveillance systems. The FAA has already developed agreements with HAI 
to support operations in the Gulf of Mexico. The FAA is open to 
implementing similar agreements as opportunities for ADS-B service 
expansion present themselves.
    While this rule does not mandate ADS-B equipage in all airspace 
classifications, the FAA is analyzing whether ADS-B services can be 
expanded to provide improved safety and capacity enhancements for low 
altitude flight operations and airports underlying non-mandated 
airspace. The FAA will work with users to identify new candidate 
airports for these services. This activity will continue throughout the 
initial implementation period and post 2013 when the nationwide ADS-B 
infrastructure is expected to be available NAS-wide.
    The extent to which ADS-B can contribute to operations in special 
use airspace is still being studied; however, the FAA is committed to 
examining any proposals for the use of ADS-B outside of the scope of 
implementation described in this rule.
3. Decommissioning Traffic Information Service-Broadcast (TIS-B)
    In the NPRM preamble, the FAA noted that once all aircraft are 
equipped with ADS-B Out, ADS-R will provide the complete traffic 
picture and the FAA will decommission TIS-B.
    A few commenters, including the DOD, questioned the assumption that 
all aircraft would be equipped for ADS-B Out. Rockwell-Collins 
recommended retaining TIS-B after the ADS-B mandate takes effect, 
because it provides a critical support for ADS-B airborne applications.
    The original purpose of TIS-B was to provide proximate traffic 
information to ADS-B In-equipped aircraft about targets that were not 
equipped with ADS-B. When this rule takes effect in 2020 aircraft 
operating in the airspace subject to this rule must be equipped with 
ADS-B, thus theoretically eliminating the need for the TIS-B service. 
However, the FAA realizes that TIS-B may still have value after 2020 as 
a backup traffic service for ADS-B In aircraft during GNSS outages or 
when an individual target's ADS-B system is inoperative. Thus, the FAA, 
outside of this rulemaking effort, will evaluate the benefits of 
continuing TIS-B past the 2020 rule compliance date.

O. Safety

    Several commenters, including AOPA, the ARC, and Boeing, suggested 
that the FAA expand the ADS-B service volume and ensure that TIS-B, 
FIS-B, and ADS-R are included in the ADS-B expanded coverage area.
    Some commenters believed that reducing primary radars would reduce 
safety. These commenters noted that primary radar is important to track 
aircraft without ADS-B. They also recommended that the FAA continue 
requiring transport category aircraft to equip with Mode S transponders 
and TCAS II as an independent collision avoidance system. Some 
commenters argued that the complexity of the ADS-B system poses a 
collision risk.
    Other commenters noted that ADS-B In cockpit displays can be 
confusing and distracting, which may cause a pilot to lose situational 
awareness. They added that the FAA should evaluate the CDTI to 
understand the additional monitoring responsibility and workload placed 
on the flightcrew. One individual contended that ADS-B will increase a 
pilot's dependence on cockpit equipment and reduce the pilot's tendency 
to look outside the aircraft. Another individual commenter asked for 
data to prove that ADS-B will not be susceptible to own-ship ghosting 
or target duplication. (``Own-ship ghosting'' is a term that is used to 
describe a traffic display showing one's own aircraft as an actual 
target. Ensuring targets that are transmitting ADS-B are not also 
transmitted as TIS-B targets helps reduce the chances of seeing one's 
own aircraft as a target on the display.)
    The final rule does not eliminate the requirement for transponders, 
TCAS, or primary radars. The FAA notes that any aircraft required to 
have TCAS II or ACAS, or that voluntarily has TCAS II or ACAS 
installed, must also be equipped with a Mode S transponder. This 
generally includes all aircraft operated under 14 CFR parts 121, 125, 
and 129, and certain aircraft operated under 14 CFR part 135.
    Mode S transponders transmit both aircraft altitude and aircraft 
identification information. Both Mode A/C transponders and Mode S 
transponders require interrogation to provide information. ADS-B In 
Conflict

[[Page 30179]]

Detection does not replace the functions of TCAS II or ACAS; however, 
future versions of hybrid surveillance systems may use passive ADS-B 
messages to reduce unnecessary interrogations and, thus, reduce 1090 
MHz spectrum congestion.
    As stated in the NPRM, the FAA is maintaining its current network 
of primary radars. However, the FAA expects to reduce a large 
percentage of its secondary radars as a result of this rule. Both 
primary surveillance radar and SSR will continue to be used for 
surveillance during the transition period of ADS-B avionics equipage.
    The benefits of certain ADS-B In applications cannot be fully 
realized in areas where there is no ADS-B coverage; however, the lack 
of ADS-B surveillance or ADS-R does not present a safety risk. When an 
aircraft is outside of the ADS-B coverage area, the ADS-R/TIS-B system 
will inform the pilot that the traffic picture is not complete. In all 
areas, regardless of ADS-B coverage, pilots will use the same 
procedures they have today to maintain safe separation of aircraft. 
TIS-B and FIS-B services are advisory and cannot be used to maneuver an 
aircraft without ATC clearance. The FAA will investigate ADS-B service 
expansion as part of the ADS-B NAS-wide implementation.
    With regard to the comment regarding own-ship ghosting, the ADS-B 
system minimizes the chance of target duplication because it will not 
transmit TIS-B data on a target that is broadcasting ADS-B. This is 
because ADS-R is designed to relay information about aircraft 
transmitting on a different broadcast link, and TIS-B is designed to 
relay information only about aircraft not broadcasting ADS-B messages.
    This rulemaking only mandates ADS-B Out, which does not involve any 
requirements for a cockpit display. Before any mandate of ADS-B In, the 
FAA will conduct extensive safety analysis and training. The current 
ADS-B Out rule does not eliminate or reduce the requirement under Sec.  
91.113 for pilots to see and avoid other aircraft.

P. Efficiency

    In the NPRM preamble, the FAA stated that ADS-B will enhance ATC 
surveillance, which will increase airspace efficiency and capacity to 
meet the predicted demand for ATC services.
    Several commenters, including the Airports Council International--
North America (ACI-NA), Boeing, and FedEx, commented on the anticipated 
efficiency improvements stated in the NPRM. Some commenters contended 
that the proposed rule did not prove that a decrease in en route 
separation of aircraft will decrease delays or increase airspace 
capacity. Two commenters argued that the FAA has not demonstrated that 
system choke points can handle the increased capacity if en route 
separation is reduced.
    Other commenters, including the National Air Traffic Controllers 
Association, argued that reducing separation will not mitigate 
commercial traffic delays caused by an inadequate number of runways, 
weather, hub-and-spoke operations, or airline scheduling practices. Era 
Corporation recommended that the FAA improve the infrastructure at 
small airports to relieve congestion. Boeing stated that ADS-B alone 
will not lead to the advances required by NextGen.
    The FAA has consistently stated that ADS-B will not produce a 
complete NextGen air traffic management solution, but rather will set 
the initial steps to achieving a NextGen solution. The airport 
infrastructure is a crucial component of the NAS. Efficiency and 
capacity of the NAS can be positively affected by improving the 
efficiency of individual flights and improving the quality of input to 
air traffic controllers. ADS-B can help maximize the use of existing 
airport infrastructure. The ability to transmit ADS-B Out messages can 
increase the efficiency of the NAS in radar airspace by providing 
accurate updates at a faster rate than many existing surveillance 
systems. This increased update rate permits ATC to merge and sequence 
aircraft more effectively into existing airport choke points, which 
should mitigate, rather than increase, congestion and delay. This 
rule's regulatory evaluation does not include any benefits that are 
dependent on, or attributable to, other NextGen systems outside the 
scope of this rulemaking.
    The FAA expects that ADS-B Out will enable the establishment of 
more direct routes outside airspace subject to this rule, which would 
use less fuel, emit less carbon dioxide and nitrogen oxide, and 
increase NAS efficiency. The FAA is currently developing specific ADS-B 
routes for certain areas that have the potential for significant 
benefits (airspace off the shore of the east coast and over the Gulf of 
Mexico). The FAA expects that other opportunities for routes enabled by 
ADS-B will emerge as the ground infrastructure is implemented NAS-wide.
1. Improved Position Reporting
    According to operational evaluations,\54\ ADS-B provides improved 
accuracy over radar in most air traffic scenarios. While some terminal 
radars can provide increased accuracy the closer the aircraft is to the 
receiver, ADS-B provides consistent position accuracy regardless of the 
aircraft's range from a receiver. ADS-B also provides more timely 
information updates than conventional radar. Unlike radar, the accuracy 
and integrity of ADS-B Out is uniform and consistent throughout the 
service areas. Therefore, ATC's ability to accurately identify and 
locate aircraft that are further away from the air traffic control 
facilities will be better than radar.
---------------------------------------------------------------------------

    \54\ Surveillance and Broadcast Services Systems Engineering 
Separation Standards Working Group, Final Report on Operational 
Evaluation of 5 NM ADS-B to Radar Separation Services in Alaska, 
November 30, 2006.
---------------------------------------------------------------------------

    ADS-B does not scan an environment in the same way as radar; 
therefore, ADS-B does not provide unnecessary returns based on weather 
or other obstructions, which can impede the effectiveness of primary 
radars.
    ADS-B provides consistent, frequently updated position reporting 
and additional aircraft information for ATC decision-support tools, 
which increases ATC confidence in aircraft position. This will allow 
ATC to apply existing separation standards more exactly and without the 
need for ATC to correct for possible radar inaccuracies. The regulatory 
evaluation provides more discussion on the benefits of improved 
surveillance information.
2. Optimized Profile Descents (OPDs)
    The FAA plans to use the information broadcast by ADS-B to better 
sequence aircraft approaching the terminal area with the development of 
a Merging and Spacing application. This ground-based system sends 
precise suggested speed instructions to en route aircraft. These exact-
speed instructions should allow aircraft to arrive at extended terminal 
area merge points at times that are much more precise than currently 
feasible.
    As part of the Merging and Spacing application, the FAA is 
developing both a ground tool and aircraft requirements that can be 
used to optimize aircraft spacing. In addition to other airspace 
efficiencies, this tool will enable a fuel-saving procedure called 
Optimized Profile Descent (OPD), previously referred to as Continuous 
Descent Arrivals (CDAs).
    OPDs are a type of terminal arrival procedure, specifically 
designed to keep an aircraft at, or near idle power during

[[Page 30180]]

the entire arrival until the final approach fix.\55\ These procedures 
increase flight efficiencies while reducing noise, fuel consumption, 
and emissions. OPDs eliminate step-down altitudes and the associated 
inefficient power adjustments. OPDs depend on minimal aircraft 
vectoring to maintain the arrival pattern. Therefore, aircraft must be 
accurately metered with ADS-B-enabled spacing and sequencing tools 
prior to and during descent and approach.
---------------------------------------------------------------------------

    \55\ The final approach fix identifies the beginning of the 
final approach segment, and is the fix from which the final 
instrument flight rule (IFR) approach to an airport is executed.
---------------------------------------------------------------------------

    Below a certain level of demand, controllers can authorize OPDs 
using current onboard equipment and procedures. As the terminal demand 
increases, it becomes progressively more difficult for controllers to 
allow OPDs because of interference with other traffic flows in the 
airspace. As demand approaches capacity, the tradeoff between total 
airport throughput (and delays) and individual flight profile 
efficiency (that is, OPDs) would most likely prohibit OPDs for very 
high traffic density situations. This situation will be aggravated over 
time as air traffic resumes growth and terminal airspace constraints 
increase.
    Many airports start to exhibit significant delays when demand 
reaches approximately 70 percent of capacity. The proposed FAA spacing 
tool, using more accurate ADS-B position information, would enable OPDs 
in medium-density terminal airspace when the demand approaches the 
point where delays would be encountered. The FAA believes that ADS-B 
Out can expand use of OPDs into medium levels of traffic density (40 
percent to 70 percent), which may not be possible without ADS-B Out. 
Accomplishing OPDs at this level of traffic density would have 
important environmental and energy benefits with no increase in 
congestion or delay.
3. Reduced Aircraft Separation
    In non-radar airspace, ADS-B Out allows ATC to apply radar-like 
separation standards in areas where ATC currently applies non-radar, 
procedural separation. In some cases, routes laterally separated 
without radar by as much as 90 NM are now separated with ADS-B at only 
20 NM. Longitudinal separation of typically 10 minutes (80 NM) can be 
reduced to 5 NM.
    Boeing commented that the accuracy and integrity values proposed in 
the NPRM will not support reduced en route separation standards. ADS-B 
position accuracy supports current surveillance standards. Experience 
with the mature system may allow reductions at a future time. The FAA 
plans to expand 3 NM separation to locations in the NAS that currently 
only permit 5 NM separation. Currently, the FAA is modeling several 
scenarios to determine if ADS-B can support 3 NM en route separation 
based on a target level of safety. The FAA will not move forward with 
reduced separation until all safety and operational analyses have been 
completed and ADS-B has been certified to perform this service.
4. Expanded Surveillance Coverage
    In the future, there may also be an opportunity for ATC to use ADS-
B Out data for surveillance in areas of the NAS below the floor or 
outside the lateral coverage of existing radar surveillance. The FAA 
does not yet know where in the NAS this extra coverage might be 
available. This information will likely not be available until ADS-B 
surveillance has already been implemented in a service area. As the FAA 
identifies areas with additional coverage, the FAA will investigate how 
this additional coverage could be used.

Q. ADS-B In

    Many commenters, including ACSS, ALPA, CAA, Lockheed Martin, the 
NTSB, and UPS, commented that the majority of the ADS-B benefits will 
be derived from ADS-B In. Numerous commenters asserted that ADS-B Out 
alone would not be cost-beneficial or provide them with any added 
benefits compared to their operations today. Some commenters noted that 
ADS-B In, however, would provide necessary services to the cockpit. 
Many of these commenters asserted that ADS-B In should be mandated as 
well. However, AOPA specifically recommended that ADS-B In be voluntary 
because it is cost-prohibitive for most GA owners. British Airways also 
questioned the business case for ADS-B In.
    Many commenters, including the DOD, ACI-NA, and AIA, pointed out 
that the capabilities and functions of ADS-B Out alone will not provide 
the full range of benefits available from ADS-B. To improve the overall 
system, they recommended developing standards for ADS-B Out in unison 
with standards for ADS-B In. GAMA and IATA recommended that the FAA 
work to define the requirements for ADS-B In to encourage ADS-B 
equipage. ATA specifically asked the FAA to define ADS-B In standards 
by 2010. IATA noted that many operators will delay upgrades until there 
is a single, defined ADS-B package with avionics and procedures to 
support NextGen and the Single European Sky Air Traffic Management 
(ATM) Research Program.
    The ARC recommended that the FAA, in partnership with industry, 
define a strategy for ADS-B In by 2012 and ensure that the strategy is 
compatible with ADS-B Out avionics. The ARC also recommended that the 
FAA describe how to proceed with ADS-B In beyond the voluntary equipage 
concept discussed in the NPRM.
    A few commenters, including NBAA, praised the benefits of ADS-B and 
recommended that the FAA resolve ADS-B In display requirements, 
including human factors. The NTSB stated that ADS-B would significantly 
improve situational awareness for pilots, especially during ground 
operations. GAMA recommended that the FAA not limit display options in 
the final rule.
    The FAA fully recognizes that ADS-B In and other future air-to-air 
applications are functions that could provide substantial benefits to 
aircraft operators and the NAS. While additional benefits can be 
accrued using ADS-B In functions, requirements for an ADS-B In system 
are not sufficiently defined to implement them at this time.
    ADS-B Out is necessary to establish an air transportation 
infrastructure that is consistent with the NextGen plan and will change 
the way the NAS operates. Further, the economic evaluation of the ADS-B 
Out proposal found the system to be cost-beneficial if ADS-B Out 
avionics costs are at the low end of the estimated cost range and if 
the benefits are at the high end of the estimated benefits range.
    Given the value of ADS-B In services to individual operators and 
the benefits to future NAS operations, the requirements adopted for 
ADS-B Out also support certain ADS-B In applications.\56\ The FAA has 
modified several aspects of the proposed rule to minimize the cost 
impact to operators of the requirements driven by ADS-B In. The 
requirements in this final rule also establish a stable infrastructure 
for current and future applications of ADS-B In.
---------------------------------------------------------------------------

    \56\ These applications include Enhanced visual acquisition, 
conflict detection, and enhanced visual approach.
---------------------------------------------------------------------------

    The FAA concurs with the ARC's recommendation to define a strategy 
for ADS-B In equipage by 2012 and is working with industry to develop a 
strategy for future ADS-B In applications. By 2012, the requirements 
and benefits of ADS-B In applications should be well enough defined for 
the

[[Page 30181]]

FAA to specify a set of performance requirements that would be tied to 
a well-defined bundle of applications.
    Furthermore, RTCA has completed the DO-317, Minimum Operational 
Performance Standards (MOPS) for Aircraft Surveillance Applications 
System (ASAS), \57\ and the FAA is currently developing a TSO to 
utilize this RTCA standard.
---------------------------------------------------------------------------

    \57\ ASAS provides the platform for the processing and display 
of ADS-B In applications.
---------------------------------------------------------------------------

R. ADS-B in Applications

    Multiple commenters, including SANDIA, asked for more information 
about potential ADS-B In applications. This information is provided 
below.
1. Surface Situational Awareness With Indications and Alerting
    This application is being designed to provide information regarding 
potential traffic conflicts on or near the airport surface to the 
flightcrew. The ADS-B In cockpit display would indicate the relevant 
runway occupancy status. Depending on the severity of the conflict, the 
system would alert the flight crew with visual and/or audible alerts.
2. In-Trail Procedures
    This application is being designed to facilitate aircraft 
conducting oceanic in-trail flight level changes using a reduced 
separation standard. This application should improve the use of oceanic 
airspace, increase efficiency, reduce fuel consumption, and increase 
safety by helping flightcrews avoid turbulent flight levels. With this 
application, ATC will continue to provide procedural non-radar 
separation services. However, the FAA is exploring whether controllers 
would be able to allow flight level changes where aircraft are 
separated by only 15 NM during climb or descent, instead of 100 NM in 
use today.
3. Interval Management
    This application is intended to improve current merging and spacing 
capabilities to ensure more consistent aircraft spacing, and 
potentially increase airspace capacity. With this application, 
controllers would issue a different set of instructions to pilots, for 
example, to maintain a given time or distance from the preceding 
aircraft. The flight crews will then use ADS-B In information to adjust 
their airspeeds or flight paths to maintain the instructed separation.
4. Airport Surface Situational Awareness and Final Approach Runway 
Occupancy Awareness
    ASSA and FAROA increase situational awareness of potential airport 
ground conflicts at several of the nation's busiest airports. However, 
the reduced NACP requirement in this rule, while sufficient 
for ADS-B Out, is not sufficient for all aircraft to use in ASSA and 
FAROA.

S. International Harmonization

    Several commenters stated that the ADS-B program technical 
standards and requirements in the NPRM may be exclusive of, and not 
harmonized with, ICAO and international efforts under way in Europe, 
Australia, and Canada. Several individual commenters and AOPA 
questioned the interoperability of UAT in international airspace, 
including Canada and Mexico. They also questioned the applicability of 
UAT through ICAO Standards and Recommended Practices (SARPs). The ARC 
recommended that the FAA advocate national policies that explicitly 
allow for the use of non-U.S. positioning sources (for example, 
Galileo) as part of the infrastructure to meet aviation performance 
requirements.
    The FAA fully supports the need for international regulators to 
focus on a global interoperability of ADS-B through the continuing 
development of standards for equipment, applications, flight 
procedures, and operating rules. The RTCA standards for DO-260B and DO-
282B (referenced in TSO-C166b and TSO-C154c) were developed with close 
international cooperation. The FAA supports the RTCA/European 
Organization for Civil Aviation Equipment (EUROCAE) Requirements Focus 
Group, which is internationally coordinating ADS-B In. Additionally, 
the FAA actively meets with EUROCONTROL, the Australian Civil Aviation 
Safety Authority, and Transport Canada to internationally coordinate 
ADS-B regulation.
    The FAA has structured the ADS-B Out program on performance 
requirements and not a specific navigation or positioning source. The 
FAA is proposing harmonized requirements for aircraft separation to 
ICAO, with the support of Australia, Canada, and EUROCONTROL. The 
United States is working with other GNSS providers to ensure system 
interoperability, improve performance, and reduce costs for integrated 
receiver equipment. This rule does not prohibit the use of 
international GNSS; any navigation source that meets the requirements 
complies with this rule.
    The performance standards for the UAT were developed by RTCA 
through international cooperation and coordination. The standards were 
published in DO-282B, (MOPS for UAT ADS-B). Additionally, DO-282B was 
developed in accordance with Annex 10 to the convention of 
international civil aviation. As such, individual states are allowed to 
invoke these standards as their own requirements.

T. Backup ATC Surveillance

    In the NPRM, the FAA described an ADS-B backup strategy that 
included a reduced network of SSRs to support high-density terminal 
airspace, all en route airspace above 18,000 feet MSL, and medium-
density terminal airspace above certain altitudes. In the proposal, the 
FAA noted that it intends to retain all primary surveillance radar as a 
means to mitigate single-aircraft avionics failures.
    Several aviation associations, air carriers, pilots, and various 
other organizations commented on the proposed backup strategy. The 
commenters suggested several potential alternatives including Automatic 
Dependent Surveillance--Contract (ADS-C), long range navigation 
(LORAN), enhanced long range navigation (eLORAN), fusion, and 
multilateration.
    Some commenters, including UPS and United Airlines, recommended 
that the FAA develop a backup system that not only backs up 
surveillance, but also works in a fusion process to increase the 
accuracy, integrity, and availability of the primary surveillance 
system. Boeing recommended that during RAIM outages, ADS-B could 
broadcast position data derived from a flight management system or an 
inertial navigation system. Other commenters questioned whether there 
was a robust and fully independent airborne- or ground-based backup 
timing system in the event of GPS timing signal loss. The DOD contended 
that the backup must be able to support planned GPS electronic testing 
and solar flare activity.
    Several commenters opposed having one interdependent service for 
both navigation and surveillance. They believed that this combination 
of navigation and surveillance could be detrimental when a pilot 
experiences a GPS outage while operating in instrument meteorological 
conditions. The ARC recommended that the FAA, in coordination with 
other Government agencies, develop an integrated communication 
navigation and

[[Page 30182]]

surveillance (CNS) strategy to address GNSS interference and outages.
    Various entities also questioned the procedures that would be in 
place for aircraft operating with a NACP value of less than 
9. One individual asked how the system will accommodate aircraft 
without ADS-B, if an entire broadcast link is inoperable.
    The FAA will provide ATC separation services for aircraft meeting 
the minimum ADS-B-required performance parameters (NACP, 
NACV, NIC, SDA, and SIL) for airspace subject to this rule. 
If, during flight, an individual aircraft does not meet the minimum 
ADS-B-required performance parameters, then ATC may provide separation 
services using the backup (for example, radar where available and 
procedural separation elsewhere). This transition will be seamless 
because secondary surveillance data will be one of several surveillance 
sources fused into the display used by ATC.
    The ADS-B ground automation combines or ``fuses'' all available 
surveillance information from ADS-B with primary surveillance radar and 
SSR. This provides a complete or ``fused'' picture of all the traffic 
operating in a given area. Multi-sensor fusion allows the automation to 
combine data from various sensors, and use the most accurate 
measurements. In most cases, a Kalman Filter Tracker optimizes the 
accuracy of track estimates from multiple sensors. In addition to 
improved aircraft position accuracy, data fusion uses all the updates 
from multiple sensors, which increases the overall update rate. The FAA 
currently uses practical trackers for data fusion with the Common-
Automated Radar Terminal System and the Standard Terminal Automation 
Replacement System.
    If the ADS-B ground infrastructure or a particular broadcast link 
is out of service, or a sufficient number of aircraft cannot meet the 
minimum required performance for a given airspace and controller 
workload is adversely impacted, ATC will use the backup system to 
provide ATC separation services for all aircraft in that airspace. 
Transition to the backup strategy will not impact the ability of ATC to 
provide separation services to the operator.
    The FAA completed the Surveillance/Positioning Backup Strategy 
Alternatives Analysis \58\ on January 8, 2007. This study included a 
comprehensive analysis of various strategies for mitigating the impact 
of the loss of GPS on ADS-B surveillance. The analysis identified a 
reduced network of SSRs as the recommended backup for ADS-B. This 
strategy retains all existing en route SSRs (150) and approximately 50 
percent of SSRs in high-density terminal areas (40).
---------------------------------------------------------------------------

    \58\ It is important to recognize that this is a performance-
based rule and does not require GNSS. For the purpose of the backup 
strategy evaluation the FAA assumed that users would equip with a 
GNSS as their position source.
---------------------------------------------------------------------------

    The FAA assessed numerous technologies as part of this analysis, 
including: Multilateration; eLORAN; distance measuring equipment (DME); 
DME/inertial reference units; satellite-based augmentation systems; 
ground-based augmentation systems; and various combinations and 
implementations of these technologies. The FAA determined the backup 
strategy based on the most effective tradeoff between performance, 
schedule, and cost factors among airborne and ground segments of the 
NAS architecture.
    This backup strategy will support continued use of the separation 
standards in effect today. However, for select areas experiencing 
degraded surveillance coverage during an outage, ATC may increase 
aircraft separation as operationally required.\59\ The FAA concludes 
that these operational capabilities are sufficient, given that loss of 
required position information is expected to be a rare event.
---------------------------------------------------------------------------

    \59\ The standard for reverting to backup surveillance is also 
discussed in H.2, System Availability.
---------------------------------------------------------------------------

    In meeting the performance standards adopted by this rule, an 
aircraft's navigation and surveillance functions may be dependent on 
the same position source. Using GNSS technology for ADS-B provides for 
improved performance (i.e., increased update rate, increased accuracy 
at long range, and cleaner surveillance picture to ATC) over other 
surveillance systems and allows for a more flexible ground 
infrastructure.
    The risks posed by this dependency have been accepted because the 
navigation and surveillance functions have independent backup systems. 
In evaluating the options, the FAA specifically considered the scenario 
in which the satellite positioning source failed. As a result, the FAA 
determined that an effective backup system could not also be satellite-
based. The FAA further determined that these backup capabilities ensure 
sufficient navigation and surveillance capabilities during a 
positioning source outage and maintain appropriate levels of safety.

U. Privacy

    The NPRM proposed requiring a message element to transmit the 
aircraft's assigned 24-bit ICAO address.
    Many commenters, including AOPA and Rockwell-Collins, strongly 
argued against ADS-B Out broadcasts of identifiable data, including 
aircraft tail number and operator name. These commenters argued that 
the information could be used to continuously watch all aircraft and 
ultimately could be used by the FAA for enforcement or assessing user 
fees. Certain commenters argued in favor of retaining the anonymous 
mode for VFR operations because aircraft identification is only 
required for ATC purposes.
    Commenters suggested several alternatives: (1) Use UAT's privacy 
message function (which allows the pilot to select ``VFR'' mode) to 
have the UAT system randomly select a 24-bit ICAO address; (2) require 
manufacturers to design ADS-B systems that archive data onboard, and 
advise pilots to archive the data so there is an independent data 
source that corroborates government data; and (3) design a system host 
configuration protocol to assign transponder codes through a unique 
address when the UAT or 1090 MHz ES is turned on. They contended that 
this would allow a network to eliminate system duplicity and guarantee 
anonymity to the pilot of the aircraft (therefore, the 24-bit Mode S 
identifiers would no longer be needed).
    The ARC made three recommendations regarding privacy: (1) The FAA 
should treat the 24-bit ICAO code assignments as information covered 
under privacy laws, so they are available only to authorized personnel 
or released by the holder; (2) the FAA should use the anonymity feature 
of UAT and develop an equivalent anonymity feature for 1090 MHz ES that 
would apply to VFR operations not using ATC services; and (3) the FAA 
should accommodate assignment of the 24-bit ICAO codes so that they do 
not easily correlate to an aircraft tail number and they permit 
aircraft call signs to be something other than the aircraft 
registration number when receiving ATC services.
    The FAA reviewed all the comments regarding privacy and notes that 
most of the commenters specifically addressed VFR operations. The FAA 
notes that there is no right to privacy when operating in the NAS. The 
FAA specifically designates airspace for which the identification of 
aircraft is necessary, so that the agency can effectively separate 
aircraft. The transponder rule specifies that an

[[Page 30183]]

aircraft operating in airspace designated in Sec.  91.215 must have ATC 
transponder equipment installed that meets the performance requirements 
of TSO-C74b, TSO-C74c, or TSO-C112.
    Many GA aircraft are equipped with Mode C, which has the capability 
to squawk 1200 and meets the requirements of Sec.  91.215, without 
specifically identifying the aircraft. Most of these commenters are 
seeking similar treatment under ADS-B so that ATC can track the 
aircraft without specifically identifying the aircraft.
    TSO-C154c includes a feature to temporarily and randomly assign a 
24-bit address for UAT-equipped aircraft. This rule does not prohibit 
the use of this feature. UAT-equipped aircraft conducting VFR 
operations that have not filed a flight plan and are not requesting ATC 
services may use this feature. Although the FAA does not prohibit the 
anonymity feature, operators using the anonymity feature will not be 
eligible to receive ATC services and will not be able to benefit from 
enhanced ADS-B search and rescue capabilities. TSO-C166b does not 
include a feature to accommodate anonymous 24-bit addresses. Should 
safety or efficiency of the NAS so require, the FAA could initiate 
rulemaking to prohibit an operator from using the anonymity feature. 
Additionally, if the FAA, in coordination with the Department of 
Homeland Security (DHS), determines that the anonymity feature is an 
unacceptable risk to security, the FAA could initiate rulemaking to 
prohibit an operator from using the anonymity feature.
    This rule does not implement any type of user fee. Subsequent 
agency rulemaking would be necessary to establish such fees. 
Furthermore, this rule does not affect the process for the FAA 
assigning the 24-bit ICAO codes.
    The FAA has not determined that archiving data onboard the aircraft 
is necessary for ATC surveillance. However, this rule does not preclude 
manufacturers from designing equipment with this function.

V. Security

    Various commenters, including the DOD, commented on the security 
aspects of the ADS-B system. They contended that, as ADS-B will 
broadcast the location and identity of users, malicious parties could 
monitor transmissions from the aircraft and ATC to obtain information 
to target and harm the aircraft. Another commenter stated that the ADS-
B information could be used by an unmanned aircraft to target passenger 
aircraft. Some commenters alleged that security safeguards are needed 
for ADS-B to protect aircraft from terrorist attacks.
    Other commenters argued that an aircraft's ADS-B transmissions or 
GPS position/timing signals could be subject to inadvertent or 
intentional interruption or loss of the GPS timing signal. Several 
commenters recommended a planned oversight feature (for example, 
requiring ADS-B ground receivers to be licensed) to ensure that only 
authorized personnel access the data collected, and that the data is 
only accessed for authorized purposes. The DOD recommended that the FAA 
work with DHS and the DOD to determine ADS-B risks and appropriate 
countermeasures.
    The FAA conducted several analyses on the security aspects of ADS-
B. These analyses include the information system for collecting data, 
transmitting and storing data, as well as risk assessments on the 
vulnerability of ADS-B broadcast messages. All FAA information, 
including ADS-B transmissions received by the FAA, that is collected, 
processed, transmitted, stored, or disseminated in its general support 
systems and applications is subject to certification and accreditation, 
under National Institutes of Standards and Technology (NIST) 
information technology standards. It is a continuing process that 
protects the confidentiality, integrity, and availability of the 
information.
    The FAA's Security Certification and Accreditation Procedures 
(SCAP) were developed in accordance with Federal law, including: (1) 
The Federal Information Security Management Act of 2002, (2) OMB 
Circular A-130 (Management of Federal Information Resources), (3) 
Federal Information Processing Standards 199, and (4) NIST Special 
Publications (SP) 800-37 (Guide for the Security Certification and 
Accreditation of Federal Information Systems), NIST SP 800-53 
(Recommended Security Controls for Federal Information Systems), and 
NIST SP 800-53A (Guide for Assessing the Security Controls in Federal 
Information Systems).
    The FAA completed the SCAP for the ADS-B system originally in 
September 2008. The FAA completed a new SCAP in October 2009 as a 
result of changes made to the ADS-B system. This process ensures that 
ADS-B does not introduce new security weaknesses. It also ensures that 
the hardware and software composing the ADS-B system meets rigid and 
well-documented standards for infrastructure security. ADS-B meets all 
qualifications and mandates of this process. As part of the SCAP, the 
system is tested annually for security compliance, and every 3 years 
the system goes through an entirely new SCAP. In addition, the FAA 
specifically assessed the vulnerability risk of ADS-B broadcast 
messages being used to target air carrier aircraft. This assessment 
contains Sensitive Security Information that is controlled under 49 CFR 
parts 1 and 1520, and its content is otherwise protected from public 
disclosure. While the agency cannot comment on the data in this study, 
it can confirm, for the purpose of responding to the comments in this 
rulemaking proceeding, that using ADS-B data does not subject an 
aircraft to any increased risk compared to the risk that is experienced 
today. As part of this process, the FAA forwarded the assessment to its 
interagency partners, including the DOD, the Transportation Security 
Administration, the Federal Bureau of Investigation, the United States 
Secret Service, and other appropriate agencies for review. These 
entities evaluated the modeling approach, analysis, and risk outcome. 
They did not identify any reason to invalidate the analysis which 
determined that ADS-B data does not increase an aircraft's 
vulnerability. The FAA commits to annual updates of this assessment to 
monitor any changes in the underlying assumptions in the risk analysis, 
and to monitor new threat information that becomes available.
    The FAA concludes that ADS-B transmissions would be no more 
susceptible to spoofing (that is, intentionally broadcasting a false 
target) or intentional jamming than that experienced with SSR 
transmissions (Mode A, C, and S) today. Spoofing of false targets and 
intentional jamming very rarely occur with the surveillance systems in 
place today.
    The ADS-B transmission signals from aircraft will be fused with 
surveillance data from both primary and secondary radars before it is 
displayed for ATC. The controllers, therefore, are receiving and 
viewing a composite of aircraft data from multiple surveillance 
systems. The FAA does not expect spoofing and jamming to occur during 
the transition to using this fused data for surveillance. This is 
because the automation will reveal the discrepancy between a spoofed or 
jammed ADS-B target and the target reported by radar and SSR position 
reports. Fusion also provides for a smooth transition to backup 
surveillance if an ADS-B system is experiencing interference. 
Furthermore, encryption of any ADS-B data would unnecessarily limit its 
use internationally.

[[Page 30184]]

    The FAA also concludes that additional certification and 
accreditation of ground equipment will not be necessary because of the 
strict SCAP provision certifying that crucial information and equipment 
are not available to unauthorized individuals.
    The FAA finds no basis at this point that ADS-B Out provides any 
greater security risks to air navigation systems to the United States. 
The FAA continues to meet regularly with DOD and DHS representatives 
regarding the use of ADS-B information and national security issues.

W. Alternatives To ADS-B

    The NPRM compared: (1) Radar as it exists today, (2) 
multilateration, and (3) ADS-B. In the NPRM, the FAA's alternatives 
analysis found radar to be the most cost-effective solution; however, 
radar would neither be effective in supporting air traffic growth over 
time nor provide the necessary technical capabilities to support the 
NextGen concept of operations.
    Several commenters indicated that the existing radar system is 
sufficient for operations. Some commenters suggested expanding the 
radar infrastructure or implementing an alternative reporting system 
using commercial off-the-shelf technologies that have a means to encode 
and transmit GPS position data.
    Other commenters believed that multilateration could provide 
similar benefits to ADS-B at a potentially lower cost. Boeing requested 
that the FAA provide an analysis explaining its conclusion that 
multilateration would not provide the same level of benefits as ADS-B. 
ATA specifically stated that they do not believe multilateration is a 
viable alternative; however, it can provide highly accurate position 
reports for surface ADS-B In applications. Several commenters objected 
to the prohibitive cost of upgrading the avionics with ADS-B because 
there are commercial products currently available that provide real 
time weather and traffic information.
    The agency has determined that the improved accuracy and update 
rate afforded by ADS-B is a critical segment of the NextGen 
infrastructure and capabilities that offer the opportunity to make the 
system more efficient. Specifically, enhanced surveillance data via 
ADS-B will improve the performance of ATC decision-support tools (URET 
and TMA) which rely on surveillance data to make predictions. The end 
result will be fewer, more efficient reroutes to avoid potential 
conflicts, as well as improved metering into the terminal area. This 
will allow increased and more efficient use of OPDs, which have lower 
energy and emissions profiles. Unlike radar and multilateration, ADS-B 
provides more detailed flight information (for example, update rate, 
velocity, and heading) that supports ground-based merging and spacing 
tools. These tools use this information to determine optimal tracks for 
ATC arrival planning.
    FIS-B and TIS-B provide the uplink of weather and traffic 
information to the cockpit. Equipping with the necessary ADS-B In 
avionics (receiver and display components) is voluntary for operators 
and is not required by the ADS-B rule. The FAA analyzed alternative 
sources for weather and traffic information. Individually, these 
alternative sources may be less costly than the ADS-B solution. 
However, the FAA's analysis showed that the bundling of surveillance, 
weather, and traffic information is cost-effective for users who have 
not already invested in alternative capabilities. The FAA compared the 
costs and benefits of ADS-B, multilateration, and radar, as well as the 
cost savings for bundling services. A report (``Exhibit 300, Attachment 
2, Business Case Analysis Report for Future Surveillance, JRC Phase 
2a'') is available in the docket for this rulemaking.
    In sum, none of the alternatives offers the range of capabilities 
nor supports the NextGen concept of operations as well as ADS-B.

X. ADS-B Equipment Scheduled Maintenance

    The NPRM did not propose any additional continuing airworthiness 
requirements associated with the installation of ADS-B avionics 
equipment. A few commenters questioned the FAA's plan for continued 
airworthiness inspections for ADS-B equipment.
    This final rule does not add any continuing airworthiness 
inspection requirements. Transponder-based ADS-B systems will still be 
required to meet the requirements of Sec.  91.413. However, ADS-B 
systems, without a transponder, do not have any new inspection 
requirements. The FAA will use the ground automation system to 
continuously monitor ADS-B functionality, which accomplishes the 
purposes of a recurrent inspection.

Y. Specific Design Parameters

    In the NPRM, the FAA proposed performance standards for ADS-B Out, 
but did not specify any specific design parameters.
    Several commenters, including the EAA, and the United States 
Parachute Association, recommended specific design parameters for ADS-B 
avionics, including size, weight, and power consumption.
    The FAA again notes that this is a performance-based rule and does 
not mandate a particular system or design specifications (including 
size, weight, or power consumption). A performance-based rule provides 
industry with the opportunity to use innovative approaches in designing 
ADS-B avionics to meet the needs of their customers.

Z. Economic Issues

    The FAA updated the cost and benefit estimates in the final 
regulatory impact analysis for this rule. For a summary of the final 
regulatory impact analysis, see Section III. The full final regulatory 
impact analysis may be found in the docket for this rulemaking. The 
following section discusses comments the FAA received on the proposal's 
regulatory evaluation. Where appropriate, the discussion includes 
information on the updated costs and benefits for this final rule.
1. ADS-B Out Equipage Cost
    The FAA estimated that costs for the proposed rule would be between 
$2.3 billion and $8.5 billion. The FAA also considered that industry 
would start to incur equipage costs in 2012, ranging from $1.27 billion 
to $7.46 billion. In the final rule, the FAA estimates total costs to 
range from $3.3 billion to $7.0 billion, and industry equipage costs to 
range from $2.5 billion to $6.2 billion.
    Several commenters, including ATA, Boeing, British Airways, Delta 
Airlines, EAA, Honeywell, NBAA, and the Regional Airline Association 
(RAA), questioned specific cost estimates in the proposal's economic 
analysis or asked for more information about the cost and benefit 
estimates. Most of the commenters believed that equipage costs for ADS-
B Out would exceed the estimates provided in the proposal.
    Several commenters, including AOPA, EAA, Embraer, and the United 
States Parachute Association, stated that the cost to equip with ADS-B 
Out was too high. Commenters pointed out that, given the value of most 
GA aircraft, the cost of equipage could represent a significant 
percentage of, or possibly exceed, the current value of the aircraft. 
Some commenters noted that costs of this magnitude could make 
recreational or business flying cost-prohibitive. Some commenters, 
including FedEx, noted that equipage costs will be significantly higher 
for aircraft not currently equipped with a certified GPS/WAAS position 
source.

[[Page 30185]]

    For the proposed rule, the FAA contacted manufacturers, industry 
associations, and ADS-B Out suppliers to estimate ADS-B equipage and 
maintenance costs by aircraft model. The proposal included industry 
estimates for the cost of installation, maintenance, additional weight, 
and the addition of ADS-B Out equipment to meet the performance 
mandate. The proposal's regulatory impact analysis also assumed that 
all active airframes in service would be retrofitted by 2020.
    The FAA expects that the increased demand for the ADS-B Out 
equipment required by this performance-based rule will result in a more 
competitive market, such that the prices may decrease in the coming 
years for certain aircraft groups. The FAA also anticipates that any 
investment in ADS-B Out equipage will increase the residual value of 
that aircraft and will allow easier access to the regulated airspace.
    The FAA agrees that equipping aircraft with ADS-B Out will cost 
more for those aircraft that are not equipped with a position source 
capable of providing the necessary accuracy and integrity. To capture 
this cost in the proposal, the FAA requested that industry categorize 
large category turbojet airplanes by classic, neo-classic, modern, and 
new production classes, as well as the existing level of airplane 
equipage for each class. However, due to the confidentiality of cost 
data, the regulatory evaluation does not present ADS-B-supplier level 
data details. The FAA fully acknowledges that the general aviation 
community will incur significant costs from this rule. However, this 
must be balanced against the foundation this capability provides in 
moving toward the NextGen infrastructure and benefits from its overall 
usage.
2. FAA Cost Savings With ADS-B Out Compared to Radar
    The FAA considered the following three systems for future NAS 
surveillance: (1) Radar, (2) multilateration, and (3) ADS-B. The FAA 
explained in the proposal that radar was the lowest cost option. Based 
on forecasts at the time of the NPRM, the FAA did not expect that radar 
could accommodate the projected increase in traffic.
    Several commenters, including EAA and RAA, stated that the ADS-B 
program would result in a cost savings to the FAA because it would have 
less radar to maintain, operate, and replace. Most of the commenters 
claimed that the ADS-B program would shift costs from the FAA to 
aircraft operators.
    The ADS-B program is not expected to result in a cost savings to 
the FAA from 2009 through 2035. As ADS-B becomes operational, the FAA 
plans to decommission some SSR. While this will reduce the operational 
costs of maintaining radar, the FAA will incur additional costs for 
ADS-B ground stations. This results in a net increase in cost for the 
FAA.
3. Business Case for ADS-B Out and In
    In the NPRM, the FAA estimated that the total costs of ADS-B Out 
and In (excluding avionics for ADS-B In), relative to the radar 
baseline, would range from $2.8 billion to $9.0 billion. The FAA 
further estimated that ADS-B Out and In would yield $13.8 billion in 
total benefits.
    The FAA concluded that ADS-B Out and In would be cost beneficial at 
a present value of 7 percent, if: The avionics costs for ADS-B Out are 
low ($670 million at a 7 percent present value) and the avionics costs 
for ADS-B In do not exceed $1.85 billion at a 7 percent present value.
    As stated in the NPRM, ADS-B Out and In would be cost beneficial at 
a 3 percent present value if: (1) The avionics costs for ADS-B Out are 
low ($950 million at a 3 percent present value) and the avionics costs 
for ADS-B In do not exceed $5.3 billion at a 3 percent present value or 
(2) the avionics costs for ADS-B Out are high ($5.35 billion at a 3 
percent present value) and the avionics costs for ADS-B In do not 
exceed $870 million.
    Boeing asked for further clarification of scenarios in which ADS-B 
may not be cost beneficial. Specifically, Boeing referred to the 3 
percent present value estimate in the NPRM with high avionics costs. 
Boeing noted that it does not believe ADS-B In avionics costs will be 
less than ADS-B Out avionics costs. Boeing also asked for the cost 
beneficial values of ADS-B Out and In at a 7 percent present value if 
avionics costs are high.
    Boeing suggested that the FAA conduct a thorough cost-benefit 
analysis for the ADS-B program, including accurate cost estimates for 
ADS-B In. Boeing further recommended that if the FAA cannot determine 
the costs associated with ADS-B In, the FAA should not include these 
costs and benefits in the economic analysis.
    Boeing also questioned why the FAA estimated the benefits for ADS-B 
Out and In at $13.9 billion in the proposal, while the FAA estimated 
the ADS-B Out and In benefits at $18.5 billion in the ``Surveillance 
and Broadcast Services Benefits Basis of Estimates'' \60\ (SBS BOE) 
report.
---------------------------------------------------------------------------

    \60\ This report was published in August 2007. A copy of this 
report is available from the Web site http://www.regulations.gov. To 
find the report, enter FAA-2007-29305-0013.1 in the search box.
---------------------------------------------------------------------------

    The FAA agrees with Boeing that if the costs of ADS-B Out avionics 
are at the high end of our estimates and if ADS-B In avionics are more 
expensive than ADS-B Out avionics, then the costs estimated for ADS-B 
Out and In will exceed the quantified benefits, given the assumptions 
in the economic evaluation. The FAA also notes that at a 7 percent 
present value with the assumptions in the economic evaluation (i.e., if 
industry costs for ADS-B Out avionics are at the high end of the 
range), then ADS-B Out and In will not be cost-beneficial. The FAA does 
not agree that the estimates in the regulatory impact analysis need to 
be consistent with the estimates in the SBS BOE report. The economic 
analysis quantifies the potential benefits that the FAA expects to 
result from adoption of the rule. The economic analysis does not 
include benefits that could be realized without the rule.
    Specifically, the regulatory impact analysis did not include 
benefits from ADS-B in Alaska or for low altitude operations in the 
Gulf of Mexico because these benefits would occur without the rule. The 
regulatory evaluation also did not include benefits related to 
controlled flight into terrain because terrain avoidance warning 
systems currently provide these benefits. Other benefits that the FAA 
did not consider in the proposal, but are in the SBS BOE, include: An 
estimate of the reduction in FAA subscription charges because of value 
added services and a reduction in costs to obtain weather information.
    In addition, the regulatory impact analysis did not specifically 
include a benefit for radar system replacement cost avoidance. Rather, 
the FAA compared the total cost of continuing full radar surveillance 
(the baseline) to the cost of providing surveillance with ADS-B. This 
included the costs of gradually discontinuing some radar and continuing 
some radar as a backup. The lower costs of radar (what is referred to 
as ``surveillance cost avoidance'' in the SBS BOE) were captured in the 
cost comparison of radar under the baseline and radar under the ADS-B 
Out scenario (the rule).
    The draft regulatory impact analysis released with the NPRM 
included a cost-benefit analysis of ADS-B Out alone, as well as for the 
scenarios for ADS-B Out and In. For the final rule,

[[Page 30186]]

the FAA also queried industry for equipage costs for ADS-B Out and In. 
Although the FAA initially attempted to capture the benefits for ADS-B 
In, upon further consideration the agency has determined that the 
performance requirements are not sufficiently developed to conduct a 
meaningful analysis. The FAA has not included ADS-B In costs and 
benefits in the final regulatory impact analysis.
4. Improved En Route Conflict Probe Benefit Performance
    In the NPRM, the FAA estimated the benefit for en route conflict 
probe at $3.3 billion.\61\ To calculate this savings, the FAA estimated 
the reduction in ATC vectors resulting from improved en route conflict 
probe. Then, the FAA attributed this time savings to direct aircraft 
operating costs and the passenger value of time.
---------------------------------------------------------------------------

    \61\ This translates to $840 million at a 7 percent present 
value or $1.8 billion at a 3 percent present value.
---------------------------------------------------------------------------

    Several commenters questioned the improved en route conflict probe 
benefit estimates. The commenters noted that the amount of time saved 
per passenger was low, compared to other delays in the overall travel 
environment (for example, late arrivals at the airport and waiting for 
baggage). They recommended that the FAA delete the passenger value of 
time from its benefit estimate.
    The FAA does not agree that the passenger value of time should be 
removed from its benefit estimate and therefore includes it in the 
final regulatory impact analysis. There has been significant discussion 
about whether small increments of time should be valued at lower rates 
than larger increments. The present state of theoretical and empirical 
knowledge does not appear to support valuing small increments of time 
less than larger ones.\62\
---------------------------------------------------------------------------

    \62\ Economic Values For FAA Investment and Regulatory 
Decisions, A Guide, Final Report Revised Oct. 3, 2007, GRA 
Incorporated.
---------------------------------------------------------------------------

5. Capacity Enhancements, Airspace Efficiency, and Fuel Saving Benefits
    In the NPRM, the FAA estimated that between 2017 and 2035, ADS-B 
would allow for more efficient handling of potential en route 
conflicts. In the NPRM, the FAA estimated this would save 410 million 
gallons of fuel and eliminate 4 million metric tons of carbon dioxide 
emissions. The FAA also noted in the initial regulatory impact analysis 
that, during this same time period, continuous descent approaches (now 
referred to as OPDs), would allow for a 10 billion pound fuel savings 
and a 14 million ton reduction in carbon dioxide emissions. 
Furthermore, the FAA noted that optimal routing over the Gulf of Mexico 
would eliminate 300,000 metric tons of carbon dioxide emissions between 
2012 and 2035. In the final regulatory impact analysis, the FAA 
estimated a net reduction in carbon dioxide emissions attributable to 
the rule and calculated a monetary value to this net reduction. See the 
full regulatory impact analysis for details.
    A few commenters, including RAA, questioned the cost savings 
associated with more efficient flights using ADS-B. Some of these 
commenters also asked the FAA to remove the discussion on reduced 
carbon dioxide emissions because the efficiency and fuel saving claims 
have not been validated.
    RAA noted that the FAA has considerable experience justifying rules 
that enhance safety, but suggested that the FAA is not experienced in 
justifying rules based on increased airspace capacity and fuel savings. 
RAA asked the FAA to validate whether the reduced vertical separation 
minimum (RVSM) program reduced fuel consumption, as estimated in the 
RVSM regulatory evaluation. RAA also noted that the benefit analysis 
should quantify the benefits that ADS-B would provide over current 
descent procedures enabled without ADS-B.
    GAMA and an individual commenter noted the environmental impact of 
airspace modernization. GAMA encouraged the FAA to provide additional 
details and quantify the benefit from fuel savings that the FAA expects 
ADS-B surveillance will provide.
    In the proposal's benefit analysis, the FAA quantified the benefits 
that ADS-B alone will provide over current, recognized OPD procedures. 
The agency agrees that the efficiency benefits are, in part, 
conceptual, and with new technologies, conceptual efficiency benefits 
analysis is the only option. While outside the scope of this 
rulemaking, as noted by a commenter, the RVSM program offers an example 
of how airspace redesign and new technological capabilities can result 
in significant efficiency and operational (fuel savings) gains.
6. Deriving Benefits From Capstone Implementation in Alaska
    In the NPRM, the FAA explained that ADS-B has been demonstrated and 
used in Alaska for terrain and traffic awareness, and that it had a 
noticeable effect on safety. Several commenters argued that Capstone is 
an insufficient basis to assume benefits from ADS-B equipage. The 
commenters noted that Capstone is a strong component of the 
justification for the system; they added that a major component of 
Capstone is the addition of terrain information and warnings. 
Commenters also noted that the flight environment in southeast Alaska 
is unlike any in the lower 48 states.
    The FAA understands that the conditions in Alaska do not translate 
to the continental United States. While the regulatory impact analysis 
does not include any benefits from Capstone, the rulemaking action does 
highlight the potential benefits derived from more accurate and timely 
positioning information from ADS-B.
7. Regional Airline Benefits
    In the NPRM, the FAA quantified the benefits as shown in Table 4.

                     Table 4--Estimated Benefits Included in the NPRM Regulatory Evaluation
----------------------------------------------------------------------------------------------------------------
                                                                   Benefit 2007    Discounted at   Discounted at
                          Benefit area                                  M$              3%              7%
----------------------------------------------------------------------------------------------------------------
Total Benefits..................................................        $9,948.5        $5,484.3        $2,657.7
Gulf of Mexico:
    High Altitude Operations....................................         2,067.2         1,104.4           509.9
    More Efficient En Route Separation Delay Savings............         1,810.6           946.1           421.3
    Additional Flights Accommodated Optimal and More Direct                256.6           158.4            88.6
     Routing....................................................
Improved En Route Conflict Probe Performance....................         3,258.1         1,774.0           840.1
More Efficient Metering Based on Improved TMA Accuracy..........         1,746.6           944.9           441.1
Increased Ability to Perform Continuous Descent Approaches......         2,876.7         1,661.0           866.6
----------------------------------------------------------------------------------------------------------------


[[Page 30187]]

    RAA expressed concern that regional operators do not have equal 
access to large airports; therefore, they will not achieve the same 
benefits as larger air carriers. RAA specifically noted that the FAA 
has not committed to a measurable reduction in aircraft-to-aircraft 
separation standards. They believed that without reduced separation 
standards, the benefits would be localized and would not apply to 
regional airlines. RAA also noted that regional aircraft typically do 
not carry life rafts and, therefore, they cannot conduct extended over-
water operations. As a result, they will not benefit from more 
efficient aircraft separation over the Gulf of Mexico.
    The FAA agrees that regional operators who cannot operate over the 
Gulf of Mexico will not attain this separation benefit. However, the 
FAA did not estimate benefits specifically for regional carriers. The 
agency expects regional airlines to benefit from ADS-B Out even without 
reduced aircraft-to-aircraft separation standards. This is because 
other benefits, including improved en route conflict probe performance, 
apply to all aircraft in Class A airspace, including regional airlines.
8. General Aviation: High Equipage Costs With Little Benefit
    In the proposal, the FAA estimated that the total cost to equip GA 
aircraft from 2012 through 2035 would range from $1.2 billion to about 
$4.5 billion with a mid-point average of nearly $2.9 billion.\63\ 
Although the FAA did not specifically estimate GA benefits in the NPRM, 
the agency now estimates that GA could receive up to $200 million in 
ADS-B Out benefits.
---------------------------------------------------------------------------

    \63\ The FAA also calculated this midpoint to be $2.1 billion at 
a 3 percent present value or $1.5 billion at a 7 percent present 
value.
---------------------------------------------------------------------------

    Numerous commenters, including AOPA and EAA, expressed concern that 
the proposed rule would require GA operators to add costly equipment to 
their aircraft, while providing these operators with few benefits. GAMA 
noted that many of the benefits for GA operators exist with ADS-B In. 
Several of the commenters noted that GA aircraft do not substantially 
contribute to delays or congestion in the NAS. They further stated that 
if ADS-B lessens traffic delays, it will benefit the airlines rather 
than the GA community. AOPA recommended that the FAA work with key 
stakeholders to identify a strategy that either removes low-altitude 
airspace users from the proposal or greatly improves the benefits for 
them.
    The FAA considered three options to resolve the GA cost benefit 
comments. First, the FAA considered modifying performance requirements 
to reduce equipage costs. Second, the FAA evaluated options to provide 
additional benefits to GA operators. Third, the FAA explored tailoring 
the rule such that fewer GA operators would be affected.
    For the first option, the FAA determined that opportunities do 
exist for reducing the equipage costs for GA operators. In the rule, 
the FAA bases the performance requirements solely on ATC separation 
services; whereas in the proposal, the performance requirements were 
based on ATC separation services and five initial ADS-B In 
applications. This change eliminated the need for ADS-B antenna 
diversity because the ATC separation services can operate effectively 
without it and the ADS-B Out benefits can be achieved. Multiple 
commenters and the ARC felt that removing antenna diversity would help 
make the rule cheaper to implement for light general aviation 
operators.
    For the second option, using comments received by the GA community, 
the FAA has identified opportunities to provide additional benefits to 
GA operators by expanding ADS-B services throughout the NAS to areas 
not currently serviced. Thus, outside of this rulemaking effort, the 
FAA intends to explore the costs and benefits for the following ADS-B 
enabled service expansions:
    (a) Expanding low altitude surveillance coverage, both in areas 
receiving increased collateral coverage from the initial ADS-B ground 
station infrastructure and in areas that could benefit from additional 
ground station coverage.
    (b) Providing radar-like terminal ATC services at airports not 
currently served.
    (c) Providing an automated mechanism for the closure of IFR flight 
plans based on the new technologies ability to detect an aircraft's 
arrival at its destination airport.
    (d) Making enhancements to current search and rescue technology and 
procedures that will assist rescue personnel in determining the last 
known location of aircraft that are reported missing.
    (e) Providing Flight Service Stations (FSSs) with ADS-B positional 
display information and assisting in the development of automation 
systems that will allow for more tailored in flight service functions.
    For the third option, the FAA looked at tailoring the ADS-B 
airspace such that the number of general aviation aircraft needing to 
equip would be minimized. Specifically the FAA considered limiting the 
rule to only Class A and B airspace. Although ADS-B surveillance is not 
as critical to the NexGen goals in lower density airspace, such as 
Class E airspace above 10,000 feet and Class C airspace, ADS-B equipage 
for all aircraft in these areas is essential to gaining the overall 
stated ADS-B benefits, realizing savings associated with radar 
decommissioning,\64\ the expansion of potential future benefits 
discussed above, and moving towards the NextGen concept of operations. 
Thus, the airspace subject to this rule remains unchanged.
---------------------------------------------------------------------------

    \64\ The costs of radar will be about $1 billion less with ADS-B 
Out, although the total ground costs of ADS-B Out with the cost to 
sustain and decommission select radar will exceed the cost of 
continuing radar without implementing ADS-B.
---------------------------------------------------------------------------

AA. Revisions To Other Regulations

    Several commenters, including ACI-NA, ACSS, ATA, United Airlines, 
and UPS, recommended changes to other regulations. Specifically, they 
recommended that the FAA update subpart F of 14 CFR part 25 to include 
ADS-B requirements. ACI-NA recommended that the FAA amend 14 CFR part 
139 to require airport surface vehicles to equip with ADS-B to prevent 
runway incursions. Airbus recommended that the FAA update advisory 
circular (AC) 120-86, Aircraft Surveillance Systems and Applications.
    This rule only amends the operating regulations in part 91. At this 
point, the FAA has not identified any ADS-B Out requirements for parts 
23, 25, 27, and 29. The FAA will issue the appropriate aircraft 
installation and operational guidance material consistent with the 
requirements of this rule upon issuance or shortly thereafter. The FAA 
is discussing with airports and the Federal Communications Commission 
whether ADS-B would benefit airport ground vehicles.

III. Regulatory Notices and Analyses

A. Paperwork Reduction Act

    As required by the Paperwork Reduction Act of 1995 (44 U.S.C. 
3507(d)), the FAA submitted a copy of the new (or amended) information 
collection requirement(s) in this final rule to the Office of 
Management and Budget (OMB) for its review. OMB assigned the number 
2120-0728 in advance, but has not yet approved the collection. Affected 
parties do not have to comply with the information collection 
requirements until the FAA publishes in the Federal Register notice of 
the approval of the control number

[[Page 30188]]

assigned by OMB for these information requirements. Approval of the 
control number notifies the public that OMB has approved these 
information collection requirements under the Paperwork Reduction Act 
of 1995.
    The FAA received comments on the proposed performance requirements 
for ADS-B Out aircraft equipment. Those comments are discussed in 
section II, Discussion of the Final Rule, elsewhere in this preamble. 
However, the agency received no comments specifically on the burden 
associated with collecting aircraft transmissions from the ADS-B Out 
equipment required by this rule.
    A description of the annual burden is shown below.
    Use: This final rule will support the information needs of the FAA 
by requiring avionics equipment that continuously transmits aircraft 
information to be received by the FAA, via automation, for use in 
providing air traffic surveillance services.
    Respondents: The average number of aircraft that will be equipped 
annually for the first 3 years--577. The number of aircraft (general 
aviation, regional, and majors) that will be equipped by 2035: 247,317.
    Frequency: ADS-B equipment will continuously transmit aircraft 
information in ``real time'' to FAA ground receivers. The information 
is collected electronically, without input by a human operator. Old 
information is overwritten on a continuous basis.
    Annual Burden Estimate: Base-case start-up cost for an ADS-B Out-
compliant transponder: $4,371.09 million (in 2009 dollars).
    An agency may not collect or sponsor the collection of information, 
nor may it impose an information collection requirement unless it 
displays a currently valid OMB control number.

B. International Compatibility

    In keeping with U.S. obligations under the Convention on 
International Civil Aviation, it is FAA policy to conform to ICAO SARPs 
to the maximum extent practicable. ATA, British Airways, and 
EUROCONTROL recommended that the FAA harmonize this rule with the 
appropriate ICAO SARPs. Considering that the long-term global 
capabilities of ADS-B are not yet fully defined, ICAO SARPs will 
continue to evolve to reflect developing ADS-B applications. In 
addition, current ICAO SARPs for the 1090 MHz ES and UAT ADS-B links 
will be updated to reflect harmonized changes to both RTCA and EUROCAE 
minimum performance standards, as appropriate, for ADS-B Out 
operations. The FAA has reviewed the existing ICAO requirements \65\ as 
related to ADS-B Out operations and has identified no differences with 
these regulations. The FAA also will continue to work with the 
international community to ensure harmonization.
---------------------------------------------------------------------------

    \65\ ICAO references: Procedures for Air Navigation Services--
Air Traffic Management, Doc 4444, Amendment 4, (24/11/05) Procedures 
for Air Navigation Services--Air Traffic Management; Doc 9694, ICAO 
Manual of Air Traffic Services Data Link Applications; Annex 2, 
Rules of the Air; Annex 4, Aeronautical Charts; Annex 6 Part II, 
Operation of Aircraft; Annex 11, Air Traffic Services; Annex 15, 
Aeronautical Information Services; Doc 9689, Manual for 
Determination of Separation Minima; Circular 311, SASP Circular--
ADS-B Comparative Assessment; Circular 278, National Plan for CNS/
ATM Systems Guidance Material; Annex 10 Vol. IV, Amendment 82, 
Aeronautical Telecommunications; Doc 9871, Technical Provisions for 
Mode S Services and Extended Squitter.
---------------------------------------------------------------------------

C. Regulatory Impact Analysis, Regulatory Flexibility Determination, 
International Trade Impact Assessment, and Unfunded Mandates Assessment

    Changes to Federal regulations must undergo several economic 
analyses. First, Executive Order 12866 directs that each Federal agency 
propose or adopt a regulation only upon a reasoned determination that 
the benefits of the intended regulation justify its costs. Second, the 
Regulatory Flexibility Act of 1980 (Pub. L. 96-354) requires agencies 
to analyze the economic impact of regulatory changes on small entities. 
Third, the Trade Agreements Act (Pub. L. 96-39) prohibits agencies from 
setting standards that create unnecessary obstacles to the foreign 
commerce of the United States. In developing U.S. standards, this Trade 
Act requires agencies to consider international standards and, where 
appropriate, that they be the basis of U.S. standards. Fourth, the 
Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4) requires agencies 
to prepare a written assessment of the costs, benefits, and other 
effects of proposed or final rules that include a Federal mandate 
likely to result in the expenditure by State, local, or tribal 
governments, in the aggregate, or by the private sector, of $100 
million or more annually (adjusted for inflation with a base year of 
1995). This portion of the preamble summarizes the FAA's analysis of 
the economic impacts of this final rule. The FAA suggests that readers 
seeking greater detail read the full regulatory impact analysis, a copy 
of which has been placed in the docket for this rulemaking.
    In conducting these analyses, the FAA has determined that this 
final rule: (1) Has benefits that justify its costs; (2) is an 
economically ``significant regulatory action'' as defined in section 
3(f) of Executive Order 12866; (3) is ``significant'' as defined in 
DOT's Regulatory Policies and Procedures; (4) will have a significant 
economic impact on a substantial number of small entities; (5) will not 
create unnecessary obstacles to the foreign commerce of the United 
States; and (6) will impose an unfunded mandate on the private sector 
but not on state, local, or tribal governments. These analyses are 
summarized below.

Regulatory Impact Analysis

    The FAA reviewed the following three alternatives for surveillance 
and found Alternative 2 (the rule) to be the preferred alternative:
    1. Baseline radar--Maintain the current radar based surveillance 
system and replace radar facilities when they wear out;
    2. ADS-B--Aircraft operators equip to meet performance requirements 
required by the rule and the FAA provides surveillance services based 
on downlinked aircraft information.
    3. Multilateration--The FAA provides surveillance using 
multilateration.

Key Assumptions

     All costs and benefits are denominated in 2009 dollars.
     The final rule will be published in 2010 and have a 
compliance date of 2020.
     Present value rates are 3% and 7%.
     Period of analysis: 2009-2035.

Benefits of the Final Rule

    The benefits of the final rule include the dollar value of savings 
in fuel, time, net reduction in CO2 emissions, and the 
consumer surplus associated with the additional flights accommodated 
because of the rule. The estimated quantified benefits of the rule 
range from $6.8 billion ($2.1 billion at 7% present value) to $8.5 
billion ($2.7 billion at 7% present value).

Costs of the Final Rule

    The estimated incremental costs of the final rule range from a low 
of $3.3 billion ($2.2 billion at 7% present value) to a high of $7.0 
billion ($4.1 billion at 7% present value). These include costs to the 
government, as well as to the aviation industry and other users of the 
NAS, to deploy ADS-B, and are incremental to maintaining surveillance 
via current technology (radar). The aviation industry would begin 
incurring costs for avionics equipage in 2012 and would incur total 
costs ranging from $2.5 billion ($1.4 billion at 7% present value) to 
$6.2 billion ($3.3 billion at 7% present value) with an estimated

[[Page 30189]]

midpoint of $4.4 billion ($2.3 billion at 7% present value) from 2012 
to 2035.

Regulatory Flexibility Determination and Analysis

Introduction and Purpose of this Analysis

    The Regulatory Flexibility Act of 1980 (Pub. L. 96-354) (RFA) 
establishes ``as a principle of regulatory issuance that agencies shall 
endeavor, consistent with the objectives of the rule and of applicable 
statutes, to fit regulatory and informational requirements to the scale 
of the businesses, organizations, and governmental jurisdictions 
subject to regulation. To achieve this principle, agencies are required 
to solicit and consider flexible regulatory proposals and to explain 
the rationale for their actions to assure that such proposals are given 
serious consideration.'' The RFA covers a wide range of small entities, 
including small businesses, not-for-profit organizations, and small 
governmental jurisdictions.
    Agencies must perform a review to determine whether a rule will 
have a significant economic impact on a substantial number of small 
entities. If the agency determines that the rule will have such an 
impact, the agency must prepare a regulatory flexibility analysis as 
described in the RFA. Section 603 of the RFA requires agencies to 
prepare and make available for public comment a final regulatory 
flexibility analysis (FRFA) describing the impact of final rules on 
small entities. As the FAA Administrator, I certify that this rule will 
have a significant economic impact on a substantial number of small 
entities. The purpose of this analysis is to provide the reasoning 
underlying this FAA determination.
    Section 603(b) of the RFA specifies the content of a FRFA.
    Each FRFA must contain:
     A description of the reasons why action by the agency is 
being considered;
     A succinct statement of the objectives of, and legal basis 
for, the final rule;
     A description and an estimate of the number of small 
entities to which the rule will apply;
     A description of the projected reporting, record keeping 
and other compliance requirements of the final rule including an 
estimate of the classes of small entities which will be subject to the 
requirement and the type of professional skills necessary for 
preparation of the report or record;
     An identification, to the extent practicable, of all 
relevant Federal rules which may duplicate, overlap, or conflict with 
the final rule;
     A description of any significant alternatives to the final 
rule which accomplish the stated objectives of applicable statutes and 
minimize any significant economic impact of the final rule on small 
entities.
     A summary of significant issues raised by public comments 
in response to the initial regulatory flexibility analysis and how the 
agency resolved those comments.

Reasons Why the Final Rule is Being Promulgated

    Public Law 108-176, referred to as ``The Century of Aviation 
Reauthorization Act,'' was enacted December 12, 2003 (Pub. L. 108-176). 
This law set forth requirements and objectives for transforming the air 
transportation system to progress further into the 21st century. 
Section 709 of this statute required the Secretary of Transportation to 
establish in the FAA a Joint Planning and Development Office (JPDO) to 
manage work related to NextGen. Among its statutorily defined 
responsibilities, the JPDO coordinates the development and use of new 
technologies to ensure that, when available, they may be used to the 
fullest potential in aircraft and in the air traffic control system.
    The FAA, the National Aeronautics and Space Administration (NASA), 
and the Departments of Commerce, Defense, and Homeland Security have 
launched an effort to align their resources to develop and further 
NextGen. The goals of NextGen, as stated in section 709, that are 
addressed by this final rule include: (1) Improving the level of 
safety, security, efficiency, quality, and affordability of the NAS and 
aviation services; (2) Taking advantage of data from emerging ground- 
and space-based communications, navigation, and surveillance 
technologies; (3) Being scalable to accommodate and encourage 
substantial growth in domestic and international transportation and 
anticipate and accommodate continuing technology upgrades and advances; 
and (4) Accommodating a wide range of aircraft operations, including 
airlines, air taxis, helicopters, GA, and unmanned aerial vehicles.
    The JPDO was also charged to create and carry out an integrated 
plan for NextGen. The NextGen Integrated Plan, transmitted to Congress 
on December 12, 2004, ensures that the NextGen system meets the air 
transportation safety, security, mobility, efficiency and capacity 
needs beyond those currently included in the FAA's Operational 
Evolution Plan (OEP).
    As described in the NextGen Integrated Plan, the current approach 
to air transportation (i.e., ground based radars tracking congested 
flyways and passing information among the control centers for the 
duration of flights) is becoming operationally obsolete. The current 
system is increasingly inefficient, and despite decreases in air 
traffic, still subject to significant delays. Resumption of growth will 
only aggravate congestion and delays, given the capabilities of the 
present system. The current method of handling air traffic flow will 
not be able to adapt to the volumes, density, and approach to managing 
air traffic in the future. The need for significant improvements 
towards operational efficiency and reduced environmental impacts, as 
well as resumed growth, will create significant challenges. Moreover, 
the diversity of aircraft is forecast to grow as the use of unmanned 
aircraft systems and very light jets are developed for special 
operations.
    The FAA believes that ADS-B technology is a key component in 
achieving many of the goals set forth in the NextGen Integrated Plan. 
This final rule is a major step toward strategically ``establishing an 
agile air traffic system that accommodates future requirements and 
readily responds to shifts in demand from all users,'' by embracing a 
new approach to surveillance that can lead to greater and more 
efficient airspace use. ADS-B technology not only assists in the 
transition to a system with less dependence on ground infrastructure 
and facilities, but also creates capabilities for precision and 
accuracy, which in turn will make the system more operationally and 
environmentally efficient.

Statement of the Legal Basis and Objectives

    The FAA's authority to issue rules regarding aviation safety is 
found in Title 49 of the United States Code. Subtitle I, Section 106, 
Federal Aviation Administration, describes the authority of the FAA 
Administrator. Subtitle VII, Aviation Programs, describes in more 
detail the scope of the agency's authority.
    This rulemaking is promulgated under the authority described in 
Subtitle VII, Part A, Subpart I, Section 40103, Sovereignty and Use of 
Airspace, and Subpart III, Section 44701, General Requirements. Under 
section 40103, the FAA is charged with prescribing regulations on: (1) 
The flight of aircraft, including regulations on safe altitudes; (2) 
the navigation, protection, and identification of aircraft; and (3) the 
safe and efficient use of the navigable airspace. Under section 44701, 
the FAA is charged with promoting safe flight of

[[Page 30190]]

civil aircraft in air commerce by prescribing regulations for 
practices, methods, and procedures the Administrator finds necessary 
for safety in air commerce.
    This final rule is within the scope of sections 40103 and 44701 
because it promulgates aircraft performance requirements to meet 
advanced surveillance needs that will accommodate projected increases 
in operations within the NAS. As more aircraft operate within the U.S. 
airspace, improved surveillance performance is necessary to continue 
balancing air transportation growth with the agency's mandate for a 
safe and efficient air transportation system.

Projected Reporting, Record Keeping and Other Requirements

    As required by the Paperwork Reduction Act of 1995 (44 U.S.C. 
3507(d)), the FAA submitted a copy of the new information collection 
requirements in this final rule to the Office of Management and Budget 
for its review. See discussion in Section III elsewhere in this 
preamble.

Overlapping, Duplicative, or Conflicting Federal Rules

    The FAA is not aware that the final rule will overlap, duplicate or 
conflict with existing Federal rules.

Significant Issues Raised by Public Comments to the Initial Regulatory 
Flexibility Analysis

    In the NPRM, the FAA addressed the impact of the proposed rule on 
small-business part 91, 121, and 135 operators with less than 1,500 
employees. The proposal noted that a substantial number of small 
entities would be significantly affected by the proposed rule.
    One individual commented and challenged the assumption that only 
small businesses directly involved in aviation would be affected. The 
commenter explained that many businesses use aircraft indirectly in 
their operations and that higher aircraft equipage costs will affect 
overall business costs. The commenter believed that one half of all 
non-turbine GA aircraft are involved in small business activity.
    Publicly available data regarding internal company financial 
statistics for GA operators is limited. Therefore, the FAA estimated 
the financial impact by obtaining a sample population of GA operators 
from (1) the U.S. DOT Form 41 filings, (2) World Aviation Directory, 
and (3) ReferenceUSA. The FAA applied this sample to U.S. Census Bureau 
data on the Small Business Administration Web site. This was done to 
develop an estimate of the total number of small businesses affected by 
the proposed rule.
    The FAA agrees that GA operators use airplanes for indirect 
business use and has determined that this final rule will have a 
significant impact on a substantial number of small businesses.

Estimated Number of Small Firms Potentially Impacted

    Under the RFA, the FAA must determine whether a rule significantly 
affects a substantial number of small entities. This determination is 
typically based on small entity size and cost thresholds that vary 
depending on the affected industry.
    Using the size standards from the Small Business Administration for 
Air Transportation and Aircraft Manufacturing, the FAA defined 
companies as small entities if they have fewer than 1,500 employees.
    The FAA considered the economic impact on small-business part 91, 
121, and 135 operators. Many of the GA aircraft that are operating 
under part 91 are not for hire or flown for profit, so the FAA does not 
include these operators in its small business impact analysis.
    This final rule will become effective in 2020. Although the FAA 
forecasts traffic and air carrier fleets to 2040, our forecasts are of 
a generic nature and do not forecast the number of small entities. 
These forecasts also do not estimate whether an operator will still be 
in business or will be a small business entity. Therefore the FAA uses 
current U.S. operator's revenues and applies the industry-provided 
costs to determine if this final rule will have a significant impact on 
a substantial number of small entity operators.
    The FAA obtained a list of part 91, 121 and 135 U.S. operators from 
the FAA Flight Standards Service. Using information provided by the 
U.S. DOT Form 41 filings, World Aviation Directory, and ReferenceUSA, 
the FAA eliminated operators that are subsidiary businesses of larger 
businesses and businesses with more than 1,500 employees from the list 
of small entities. In many cases, the employment and annual revenue 
data are not public, so the FAA did not include these companies in its 
analysis. For the remaining businesses, the FAA obtained company 
revenue and employment from the above three sources.
    The methodology discussed above resulted in a list of 34 U.S. part 
91, 121 and 135 operators, with less than 1,500 employees, who operate 
341 airplanes. Due to the sparse amount of publicly available data on 
internal company financial statistics for small entities, it was not 
feasible to estimate the total population of small entities affected by 
this final rule. The total population of U.S. part 91, 121 and 135 
operators, with less than 1,500 employees, has the potential to be 
large. We used this sample set of small business operators to develop 
percentage estimates to apply to the U.S. Census Bureau data to 
estimate the population.
    These 34 U.S. small entity operators are a representative sample. 
The sample was used to assess the cost impact on the total population 
of small businesses who operate aircraft affected by this final 
rulemaking. This representative sample was then applied to the U.S. 
Census Bureau data on the Small Business Administration's Web site to 
develop an estimate of the total number of affected small business 
entities.
    The U.S. Census Bureau data lists small entities in the air 
transportation industry that employ less than 500 employees. Other 
small businesses may own aircraft and may not be included in the U.S. 
Census Bureau air transportation industry category. Therefore our 
estimate of the number of small entities affected by this final rule 
will likely be understated. The estimate of the total number of 
affected small entities is developed below.

Cost and Affordability for Small Entities

    To assess the cost impact to small business part 91, 121 and 135 
operators, the FAA contacted manufacturers, industry associations, and 
ADS-B equipage providers to estimate ADS-B equipage costs. The FAA 
requested estimates of airborne installation costs, by aircraft model, 
for the output parameters listed in the ``Equipment Specifications'' 
section of the Regulatory Impact Analysis.
    To satisfy the manufacturers' request to keep individual aircraft 
pricing confidential, the FAA calculated low, baseline, and high range 
of costs by equipment class. The baseline estimate equals the average 
of the low and high industry cost estimates. The dollar value ranges 
consist of a wide variety of avionics within each aircraft group. The 
aircraft architecture within each equipment group can vary, causing 
different carriage, labor, and wiring requirements for the installation 
of ADS-B. Volume discounting, versus single line purchasing, also 
affects the dollar value ranges. On the low end, the dollar value may 
represent a software upgrade or original equipment manufacturer (OEM) 
option change. On the high end, the dollar value may represent a new 
installation of upgraded

[[Page 30191]]

avionic systems necessary to assure accuracy, reliability and safety. 
The FAA used the estimated baseline dollar value cost by equipment 
class in determining the impact to small business entities.
    The FAA estimated each operator's total compliance cost as follows: 
Multiplying the baseline dollar value cost (by equipment class) by the 
number of aircraft each small business operator currently has in its 
fleet. The FAA summed these costs by equipment class and group. The FAA 
then measured the economic impact on small entities by dividing the 
estimated baseline dollar value compliance cost for their fleet by the 
small entity's annual revenue.
    Each equipment group operated by a small entity may have to comply 
with different requirements in the final rule, depending on the state 
of the aircraft's avionics. In the ``ADS-B Out Equipage Cost Estimate'' 
section of the Regulatory Impact Analysis, the FAA details its 
methodology to estimate operators' total compliance cost by equipment 
group.
    For small entity operators in the sample population of 34 small 
aviation entities, the ADS-B cost is estimated to be: (1) Greater than 
2% of annual revenues for about 35% of the operators; and (2) greater 
than 1% of annual revenues for about 54% of the operators. Applying 
these percentages to the air transportation industry category of the 
2006 U.S. Census Bureau data, the ADS-B cost is estimated to be: (1) 
Greater than 2% of annual revenues for at least 1,015 small entities; 
and (2) greater than 1% of annual revenues for at least 1,562 small 
entity operators.
    As a result of the above analysis, the FAA has determined that a 
substantial number of small entities will be significantly affected by 
the rule. Every small entity that operates an aircraft in the airspace 
defined by this final rule will be required to install ADS-B out 
equipage and therefore will be affected by this rulemaking.

Business Closure Analysis

    For commercial operators, the ratio of costs to annual revenue 
shows that 7 of 34 small business air operator firms would have ratios 
in excess of 5%. Since many of the other commercial small business air 
operator firms do not make their annual revenue publicly available, it 
is difficult to assess the financial impact of this final rule on their 
business. To fully assess whether this final rule could force a small 
entity into bankruptcy requires more financial information than is 
publicly available.
    In the NPRM, the FAA requested comment and supporting 
justification, from small entities, to assist the FAA in determining 
the degree of hardship the final rule will have on these entities. 
Comments were also requested on feasible alternative methods of 
compliance. The FAA did not receive any comments specific to this 
request.

Competitive Analysis

    The aviation industry is an extremely competitive industry with 
slim profit margins. The number of operators who entered the industry 
and have stopped operations because of mergers, acquisitions, or 
bankruptcy litters the history of the aviation industry.
    The FAA analyzed five years of operating profits for the affected 
small-entity operators listed above, and was able to determine the 
operating profit for 18 of the 34 small business entities. The FAA 
discovered that the average operating profit for 33% of these 18 
affected operators was negative. Only four of the 18 affected operators 
had average annual operating profits that exceeded $10,000,000.
    In this competitive industry, cost increases imposed by this 
regulation will be hard to recover by raising prices, especially by 
those operators showing an average five-year negative operating profit. 
Further, large operators may be able to negotiate better pricing from 
outside firms for inspections and repairs, so small operators may need 
to raise their prices more than large operators. These factors make it 
difficult for small operators to recover their compliance costs by 
raising prices. If small operators cannot recover all the additional 
costs imposed by this regulation, market shares could shift to the 
large operators.
    Small operators successfully compete in the aviation industry by 
providing unique services and controlling costs. The extent to which 
affected small entities operate in niche markets will affect their 
ability to pass on costs. Currently small operators are much more 
profitable than established major scheduled carriers. This final rule 
will offset some of the advantages of lower capital costs of older 
aircraft.
    Overall, in terms of competition, this rulemaking reduces small 
operators' ability to compete.

Disproportionality Analysis

    The disproportionately higher impact of the final rule on the 
fleets of small operators results in disproportionately higher costs to 
small operators. Due to the potential of fleet discounts, large 
operators may be able to negotiate better pricing from outside sources 
for inspections, installation, and ADS-B hardware purchases.
    Based on the percent of potentially affected current airplanes over 
the analysis period, small U.S. business operators may bear a 
disproportionate impact from the final rule.

Analysis of Alternatives

Alternative One

    The status quo alternative has compliance costs to continue the 
operation and commissioning of radar sites. The FAA rejected this 
status quo alternative because it is becoming operationally obsolete to 
use ground-based radars to track congested airways and pass information 
among control centers for the duration of flights. The current system 
is not able to upgrade to the NextGen capabilities, nor accommodate the 
estimated increases in air traffic, which would result in mounting 
delays or limitations in service for many areas.

Alternative Two

    Alternative Two would employ a technology called multilateration. 
Multilateration is a separate type of secondary surveillance system 
that is not radar-based and has limited deployment in the U.S. At a 
minimum, multilateration requires at least four ground stations to 
deliver the same volume of coverage and integrity of information as 
ADS-B, because of the need to ``triangulate'' the aircraft's position.
    Multilateration is a process that determines aircraft position by 
using the difference in time of arrival of a signal from an aircraft at 
a series of receivers on the ground. Multilateration meets the need for 
accurate surveillance and is less costly than ADS-B (however, more 
costly than radar), but cannot achieve the same level of benefits as 
ADS-B, such as system capacity and environmental improvements. 
Multilateration would provide the same benefits as radar, but the FAA 
estimates that the cost of providing multilateration (including the 
cost to sustain radar until multilateration is operational), would 
exceed the cost to continue full radar surveillance.

Alternative Three

    Alternative Three would provide relief by having the FAA provide an 
exemption to small air carriers from all requirements of this rule. 
This alternative would mean that small air carriers would rely on the 
status quo ground-based radars to track their flights and pass 
information among control centers for the duration of the flights.
    As discussed previously, ADS-B Out cannot be used effectively as 
the

[[Page 30192]]

primary surveillance system if certain categories of airspace users are 
subject to separate surveillance systems. The small air carriers 
operate in the same airspace as the larger carriers and general 
aviation. Such an exemption would require two primary surveillance 
systems, which adds the cost of an additional surveillance system 
without improving the existing benefits. Thus, this alternative is not 
considered to be acceptable.

Alternative Four

    Alternative Four exempts small-piston engine GA operators from the 
requirements of this final rule. This final rule provides minimal 
benefits to small-piston engine GA operators, while adding significant 
costs by mandating these operators to retrofit and equip about 150,000 
small piston engine GA airplanes with ADS-B Out. Even though the FAA 
determined that the percentage of small piston engine GA airplanes 
operating at the top Operational Evolution Plan 35 airports is less 
than 5%, the number of GA operations within a 30-nautical-mile radius 
of these airports is significant. This alternative was not considered 
acceptable because ADS-B equipage for all aircraft operating in the 
airspace subject to this rule is essential to gaining the overall 
stated ADS-B benefits, realizing savings associated with radar 
decommissioning, and the expansion of potential future benefits.

Alternative Five

    This alternative is the final ADS-B rule. ADS-B does not employ 
different classes of receiving equipment or provide different 
information based on its location. Therefore, controllers will not have 
to account for transitions between surveillance solutions as an 
aircraft moves closer to or farther away from an airport. To address 
congestion and delay, fuel consumption, emissions, and future demand 
for air travel without significant delays or denial of service, the FAA 
found ADS-B to be the most cost-effective solution to maintain a viable 
air transportation system. ADS-B provides a wider range of services to 
aircraft users and could enable applications that are not available 
with multilateration or radar.

International Trade Impact Analysis

    The Trade Agreements Act of 1979 (Pub. L. 96-39), as amended by the 
Uruguay Round Agreements Act (Pub. L. 103-465), prohibits Federal 
agencies from establishing standards or engaging in related activities 
that create unnecessary obstacles to the foreign commerce of the United 
States. Pursuant to these Acts, the establishment of standards is not 
considered an unnecessary obstacle to the foreign commerce of the 
United States, so long as the standard has a legitimate domestic 
objective, such the protection of safety, and does not operate in a 
manner that excludes imports that meet this objective. The statute also 
requires consideration of international standards and, where 
appropriate, that they be the basis for U.S. standards. The FAA has 
assessed the potential effect of this final rule and determined that it 
will impose the same unit costs on domestic and international entities 
and thus has a neutral trade impact.

Unfunded Mandates Assessment

    Title II of the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-
4) requires each Federal agency to prepare a written statement 
assessing the effects of any Federal mandate in a proposed or final 
agency rule that may result in an expenditure of $100 million or more 
(in 1995 dollars) in any one year by State, local, and tribal 
governments, in the aggregate, or by the private sector; such a mandate 
is deemed to be a ``significant regulatory action.'' The FAA currently 
uses an inflation-adjusted value of $136.1 million in lieu of $100 
million. This rule is not expected to impose significant costs on small 
governmental jurisdictions such as State, local, or tribal governments. 
However, the rule will result in an unfunded mandate on the private 
sector because it will result in expenditures in excess of the $136.1 
million annual threshold. The FAA considered two alternatives to the 
rule, as described above, and four alternatives in the regulatory 
flexibility analysis described above.

VI. Executive Order 13132, Federalism

    The FAA has analyzed this final rule under the principles and 
criteria of Executive Order 13132, Federalism. We determined that this 
action will not have a substantial direct effect on the States, or the 
relationship between the Federal Government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government, and, therefore, does not have federalism implications.

VII. Regulations Affecting Intrastate Aviation in Alaska

    Section 1205 of the FAA Reauthorization Act of 1996 (110 Stat. 
3213) requires the FAA, when modifying its regulations in a manner 
affecting intrastate aviation in Alaska, to consider the extent to 
which Alaska is not served by transportation modes other than aviation, 
and to establish appropriate regulatory distinctions. The FAA did not 
receive any comments on whether the proposed rule should apply 
differently to intrastate aviation in Alaska. The FAA has determined, 
based on the administrative record of this rulemaking, that there is no 
need to make any regulatory distinctions applicable to intrastate 
aviation in Alaska.

VIII. Environmental Analysis

    FAA Order 1050.1E identifies FAA actions that are categorically 
excluded from preparation of an environmental assessment or 
environmental impact statement under the National Environmental Policy 
Act in the absence of extraordinary circumstances. The FAA has 
determined that this rulemaking action qualifies for the categorical 
exclusion identified in paragraph 312f and involves no extraordinary 
circumstances.

IX. Regulations That Significantly Affect Energy Supply, Distribution, 
or Use

    The FAA has analyzed this final rule under Executive Order 13211, 
Actions Concerning Regulations that Significantly Affect Energy Supply, 
Distribution, or Use (May 18, 2001). The FAA has determined that it is 
not a ``significant regulatory action'' under Executive Order 13211. 
This is because, while it is a ``significant regulatory action'' under 
Executive Order 12866 and DOT's Regulatory Policies and Procedures, it 
is not likely to have a significant adverse effect on the supply, 
distribution, or use of energy. In fact, adoption of this final rule 
offers the potential to produce reductions in energy use in the NAS.

X. Availability of Rulemaking Documents

    You can get an electronic copy of rulemaking documents using the 
Internet by--
    1. Searching the Federal eRulemaking Portal at http://
www.regulations.gov;
    2. Visiting the FAA's Regulations and Policies Web page at http://
www.faa.gov/regulations_policies/; or
    3. Accessing the Government Printing Office's Web page at http://
www.gpoaccess.gov/fr/index.html.
    You can also get a copy by sending a request to the Federal 
Aviation Administration, Office of Rulemaking, ARM-1, 800 Independence 
Avenue SW., Washington, DC 20591, or by calling (202) 267-9680. Be sure 
to identify the amendment number or docket number of this rulemaking.

[[Page 30193]]

    Anyone is able to search the electronic form of all comments 
received into any of our dockets by the name of the individual 
submitting the comment (or signing the comment, if submitted on behalf 
of an association, business, labor union, etc.). You may review DOT's 
complete Privacy Act statement in the Federal Register published on 
April 11, 2000 (Volume 65, Number 70; Pages 19477-78) or you may visit 
http://DocketsInfo.dot.gov.

Small Business Regulatory Enforcement Fairness Act

    The Small Business Regulatory Enforcement Fairness Act (SBREFA) of 
1996 requires the FAA to comply with small entity requests for 
information or advice about compliance with statutes and regulations 
within its jurisdiction. If you are a small entity and you have a 
question regarding this document, you may contact your local FAA 
official, or the person listed under the FOR FURTHER INFORMATION 
CONTACT heading at the beginning of the preamble. You can find out more 
about SBREFA on the Internet at http://www.faa.gov/regulations_
policies/rulemaking/sbre_act/.

List of Subjects in 14 CFR Part 91

    Aircraft, Airmen, Air traffic control, Aviation safety, 
Incorporation by Reference, Reporting, and recordkeeping requirements.

The Amendment

0
In consideration of the foregoing, the Federal Aviation Administration 
amends chapter I of 14 CFR as follows:

PART 91--GENERAL OPERATING AND FLIGHT RULES

0
1. The authority citation for part 91 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 1155, 40103, 40113, 40120, 44101, 
44111, 44701, 44704, 44709, 44711, 44712, 44715, 44716, 44717, 
44722, 46306, 46315, 46316, 46504, 46506-46507, 47122, 47508, 47528-
47531, articles 12 and 29 of the Convention on International Civil 
Aviation (61 stat. 1180).


0
2. Amend Sec.  91.1 by revising paragraph (b) to read as follows:


Sec.  91.1  Applicability.

* * * * *
    (b) Each person operating an aircraft in the airspace overlying the 
waters between 3 and 12 nautical miles from the coast of the United 
States must comply with Sec. Sec.  91.1 through 91.21; Sec. Sec.  
91.101 through 91.143; Sec. Sec.  91.151 through 91.159; Sec. Sec.  
91.167 through 91.193; Sec.  91.203; Sec.  91.205; Sec. Sec.  91.209 
through 91.217; Sec.  91.221, Sec.  91.225; Sec. Sec.  91.303 through 
91.319; Sec. Sec.  91.323 through 91.327; Sec.  91.605; Sec.  91.609; 
Sec. Sec.  91.703 through 91.715; and Sec.  91.903.
* * * * *

0
3. Amend Sec.  91.130 by revising paragraph (d) to read as follows:


Sec.  91.130  Operations in Class C airspace.

* * * * *
    (d) Equipment requirements. Unless otherwise authorized by the ATC 
having jurisdiction over the Class C airspace area, no person may 
operate an aircraft within a Class C airspace area designated for an 
airport unless that aircraft is equipped with the applicable equipment 
specified in Sec.  91.215, and after January 1, 2020, Sec.  91.225.
* * * * *

0
4. Amend Sec.  91.131 by revising paragraph (d) to read as follows:


Sec.  91.131  Operations in Class B airspace.

* * * * *
    (d) Other equipment requirements. No person may operate an aircraft 
in a Class B airspace area unless the aircraft is equipped with--
    (1) The applicable operating transponder and automatic altitude 
reporting equipment specified in Sec.  91.215 (a), except as provided 
in Sec.  91.215 (e), and
    (2) After January 1, 2020, the applicable Automatic Dependent 
Surveillance-Broadcast Out equipment specified in Sec.  91.225.

0
5. Amend Sec.  91.135 by revising paragraph (c) to read as follows:


Sec.  91.135  Operations in Class A airspace.

* * * * *
    (c) Equipment requirements. Unless otherwise authorized by ATC, no 
person may operate an aircraft within Class A airspace unless that 
aircraft is equipped with the applicable equipment specified in Sec.  
91.215, and after January 1, 2020, Sec.  91.225.
* * * * *

0
6. Amend Sec.  91.217 by redesignating paragraphs (a) through (c) as 
paragraphs (a)(1) through (a)(3), redesignating the introductory text 
as paragraph (a) introductory text, and by adding paragraph (b) to read 
as follows:


Sec.  91.217  Data correspondence between automatically reported 
pressure altitude data and the pilot's altitude reference.

* * * * *
    (b) No person may operate any automatic pressure altitude reporting 
equipment associated with a radar beacon transponder or with ADS-B Out 
equipment unless the pressure altitude reported for ADS-B Out and Mode 
C/S is derived from the same source for aircraft equipped with both a 
transponder and ADS-B Out.

0
7. Add Sec.  91.225 to read as follows:


Sec.  91.225  Automatic Dependent Surveillance-Broadcast (ADS-B) Out 
equipment and use.

    (a) After January 1, 2020, and unless otherwise authorized by ATC, 
no person may operate an aircraft in Class A airspace unless the 
aircraft has equipment installed that--
    (1) Meets the requirements in TSO-C166b, Extended Squitter 
Automatic Dependent Surveillance-Broadcast (ADS-B) and Traffic 
Information Service-Broadcast (TIS-B) Equipment Operating on the Radio 
Frequency of 1090 Megahertz (MHz); and
    (2) Meets the requirements of Sec.  91.227.
    (b) After January 1, 2020, and unless otherwise authorized by ATC, 
no person may operate an aircraft below 18,000 feet MSL and in airspace 
described in paragraph (d) of this section unless the aircraft has 
equipment installed that--
    (1) Meets the requirements in--
    (i) TSO-C166b; or
    (ii) TSO-C154c, Universal Access Transceiver (UAT) Automatic 
Dependent Surveillance-Broadcast (ADS-B) Equipment Operating on the 
Frequency of 978 MHz;
    (2) Meets the requirements of Sec.  91.227.
    (c) Operators with equipment installed with an approved deviation 
under Sec.  21.618 of this chapter also are in compliance with this 
section.
    (d) After January 1, 2020, and unless otherwise authorized by ATC, 
no person may operate an aircraft in the following airspace unless the 
aircraft has equipment installed that meets the requirements in 
paragraph (b) of this section:
    (1) Class B and Class C airspace areas;
    (2) Except as provided for in paragraph (e) of this section, within 
30 nautical miles of an airport listed in appendix D, section 1 to this 
part from the surface upward to 10,000 feet MSL;
    (3) Above the ceiling and within the lateral boundaries of a Class 
B or Class C airspace area designated for an airport upward to 10,000 
feet MSL;
    (4) Except as provided in paragraph (e) of this section, Class E 
airspace within the 48 contiguous states and the District of Columbia 
at and above 10,000 feet MSL, excluding the airspace at and below 2,500 
feet above the surface; and
    (5) Class E airspace at and above 3,000 feet MSL over the Gulf of 
Mexico from the coastline of the United States out to 12 nautical 
miles.
    (e) The requirements of paragraph (b) of this section do not apply 
to any

[[Page 30194]]

aircraft that was not originally certificated with an electrical 
system, or that has not subsequently been certified with such a system 
installed, including balloons and gliders. These aircraft may conduct 
operations without ADS-B Out in the airspace specified in paragraphs 
(d)(2) and (d)(4) of this section. Operations authorized by this 
section must be conducted--
    (1) Outside any Class B or Class C airspace area; and
    (2) Below the altitude of the ceiling of a Class B or Class C 
airspace area designated for an airport, or 10,000 feet MSL, whichever 
is lower.
    (f) Each person operating an aircraft equipped with ADS-B Out must 
operate this equipment in the transmit mode at all times.
    (g) Requests for ATC authorized deviations from the requirements of 
this section must be made to the ATC facility having jurisdiction over 
the concerned airspace within the time periods specified as follows:
    (1) For operation of an aircraft with an inoperative ADS-B Out, to 
the airport of ultimate destination, including any intermediate stops, 
or to proceed to a place where suitable repairs can be made or both, 
the request may be made at any time.
    (2) For operation of an aircraft that is not equipped with ADS-B 
Out, the request must be made at least 1 hour before the proposed 
operation.
    (h) The standards required in this section are incorporated by 
reference with the approval of the Director of the Office of the 
Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. All approved 
materials are available for inspection at the FAA's Office of 
Rulemaking (ARM-1), 800 Independence Avenue, SW., Washington, DC 20590 
(telephone 202-267-9677), or at the National Archives and Records 
Administration (NARA). For information on the availability of this 
material at NARA, call 202-741-6030, or go to http://www.archives.gov/
federal_register/code_of_federal_ regulations/ibr_locations.html. 
This material is also available from the sources indicated in 
paragraphs (h)(1) and (h)(2) of this section.
    (1) Copies of Technical Standard Order (TSO)-C166b, Extended 
Squitter Automatic Dependent Surveillance-Broadcast (ADS-B) and Traffic 
Information Service-Broadcast (TIS-B) Equipment Operating on the Radio 
Frequency of 1090 Megahertz (MHz) (December 2, 2009) and TSO-C154c, 
Universal Access Transceiver (UAT) Automatic Dependent Surveillance-
Broadcast (ADS-B) Equipment Operating on the Frequency of 978 MHz 
(December 2, 2009) may be obtained from the U.S. Department of 
Transportation, Subsequent Distribution Office, DOT Warehouse M30, 
Ardmore East Business Center, 3341 Q 75th Avenue, Landover, MD 20785; 
telephone (301) 322-5377. Copies of TSO -C166B and TSO-C154c are also 
available on the FAA's Web site, at http://www.faa.gov/aircraft/air_
cert/design_approvals/tso/. Select the link ``Search Technical 
Standard Orders.''
    (2) Copies of Section 2, Equipment Performance Requirements and 
Test Procedures, of RTCA DO-260B, Minimum Operational Performance 
Standards for 1090 MHz Extended Squitter Automatic Dependent 
Surveillance-Broadcast (ADS-B) and Traffic Information Services-
Broadcast (TIS-B), December 2, 2009 (referenced in TSO-C166b) and 
Section 2, Equipment Performance Requirements and Test Procedures, of 
RTCA DO-282B, Minimum Operational Performance Standards for Universal 
Access Transceiver (UAT) Automatic Dependent Surveillance-Broadcast 
(ADS-B), December 2, 2009 (referenced in TSO C-154c) may be obtained 
from RTCA, Inc., 1828 L Street, NW., Suite 805, Washington, DC 20036-
5133, telephone 202-833-9339. Copies of RTCA DO-260B and RTCA DO-282B 
are also available on RTCA Inc.'s Web site, at http://www.rtca.org/
onlinecart/allproducts.cfm.


0
8. Add Sec.  91.227 to read as follows:


Sec.  91.227  Automatic Dependent Surveillance-Broadcast (ADS-B) Out 
equipment performance requirements.

    (a) Definitions. For the purposes of this section:
    ADS-B Out is a function of an aircraft's onboard avionics that 
periodically broadcasts the aircraft's state vector (3-dimensional 
position and 3-dimensional velocity) and other required information as 
described in this section.
    Navigation Accuracy Category for Position (NACP) specifies the 
accuracy of a reported aircraft's position, as defined in TSO-C166b and 
TSO-C154c.
    Navigation Accuracy Category for Velocity (NACV) specifies the 
accuracy of a reported aircraft's velocity, as defined in TSO-C166b and 
TSO-C154c.
    Navigation Integrity Category (NIC) specifies an integrity 
containment radius around an aircraft's reported position, as defined 
in TSO-C166b and TSO-C154c.
    Position Source refers to the equipment installed onboard an 
aircraft used to process and provide aircraft position (for example, 
latitude, longitude, and velocity) information.
    Source Integrity Level (SIL) indicates the probability of the 
reported horizontal position exceeding the containment radius defined 
by the NIC on a per sample or per hour basis, as defined in TSO-C166b 
and TSO-C154c.
    System Design Assurance (SDA) indicates the probability of an 
aircraft malfunction causing false or misleading information to be 
transmitted, as defined in TSO-C166b and TSO-C154c.
    Total latency is the total time between when the position is 
measured and when the position is transmitted by the aircraft.
    Uncompensated latency is the time for which the aircraft does not 
compensate for latency.
    (b) 1090 MHz ES and UAT Broadcast Links and Power Requirements--
    (1) Aircraft operating in Class A airspace must have equipment 
installed that meets the antenna and power output requirements of Class 
A1, A1S, A2, A3, B1S, or B1 equipment as defined in TSO-C166b, Extended 
Squitter Automatic Dependent Surveillance-Broadcast (ADS-B) and Traffic 
Information Service-Broadcast (TIS-B) Equipment Operating on the Radio 
Frequency of 1090 Megahertz (MHz).
    (2) Aircraft operating in airspace designated for ADS-B Out, but 
outside of Class A airspace, must have equipment installed that meets 
the antenna and output power requirements of either:
    (i) Class A1, A1S, A2, A3, B1S, or B1 as defined in TSO-C166b; or
    (ii) Class A1H, A1S, A2, A3, B1S, or B1 equipment as defined in 
TSO-C154c, Universal Access Transceiver (UAT) Automatic Dependent 
Surveillance-Broadcast (ADS-B) Equipment Operating on the Frequency of 
978 MHz.
    (c) ADS-B Out Performance Requirements for NAC P, NACV, NIC, SDA, 
and SIL--
    (1) For aircraft broadcasting ADS-B Out as required under Sec.  
91.225 (a) and (b)--
    (i) The aircraft's NACP must be less than 0.05 nautical 
miles;
    (ii) The aircraft's NACV must be less than 10 meters per 
second;
    (iii) The aircraft's NIC must be less than 0.2 nautical miles;
    (iv) The aircraft's SDA must be 2; and
    (v) The aircraft's SIL must be 3.
    (2) Changes in NACP, NACV, SDA, and SIL must 
be broadcast within 10 seconds.
    (3) Changes in NIC must be broadcast within 12 seconds.
    (d) Minimum Broadcast Message Element Set for ADS-B Out. Each 
aircraft must broadcast the following

[[Page 30195]]

information, as defined in TSO-C166b or TSO-C154c. The pilot must enter 
information for message elements listed in paragraphs (d)(7) through 
(d)(10) of this section during the appropriate phase of flight.
    (1) The length and width of the aircraft;
    (2) An indication of the aircraft's latitude and longitude;
    (3) An indication of the aircraft's barometric pressure altitude;
    (4) An indication of the aircraft's velocity;
    (5) An indication if TCAS II or ACAS is installed and operating in 
a mode that can generate resolution advisory alerts;
    (6) If an operable TCAS II or ACAS is installed, an indication if a 
resolution advisory is in effect;
    (7) An indication of the Mode 3/A transponder code specified by 
ATC;
    (8) An indication of the aircraft's call sign that is submitted on 
the flight plan, or the aircraft's registration number, except when the 
pilot has not filed a flight plan, has not requested ATC services, and 
is using a TSO-C154c self-assigned temporary 24-bit address;
    (9) An indication if the flightcrew has identified an emergency, 
radio communication failure, or unlawful interference;
    (10) An indication of the aircraft's ``IDENT'' to ATC;
    (11) An indication of the aircraft assigned ICAO 24-bit address, 
except when the pilot has not filed a flight plan, has not requested 
ATC services, and is using a TSO-C154c self-assigned temporary 24-bit 
address;
    (12) An indication of the aircraft's emitter category;
    (13) An indication of whether an ADS-B In capability is installed;
    (14) An indication of the aircraft's geometric altitude;
    (15) An indication of the Navigation Accuracy Category for Position 
(NACP);
    (16) An indication of the Navigation Accuracy Category for Velocity 
(NACV);
    (17) An indication of the Navigation Integrity Category (NIC);
    (18) An indication of the System Design Assurance (SDA); and
    (19) An indication of the Source Integrity Level (SIL).
    (e) ADS-B Latency Requirements--
    (1) The aircraft must transmit its geometric position no later than 
2.0 seconds from the time of measurement of the position to the time of 
transmission.
    (2) Within the 2.0 total latency allocation, a maximum of 0.6 
seconds can be uncompensated latency. The aircraft must compensate for 
any latency above 0.6 seconds up to the maximum 2.0 seconds total by 
extrapolating the geometric position to the time of message 
transmission.
    (3) The aircraft must transmit its position and velocity at least 
once per second while airborne or while moving on the airport surface.
    (4) The aircraft must transmit its position at least once every 5 
seconds while stationary on the airport surface.
    (f) Equipment with an approved deviation. Operators with equipment 
installed with an approved deviation under Sec.  21.618 of this chapter 
also are in compliance with this section.
    (g) Incorporation by Reference. The standards required in this 
section are incorporated by reference with the approval of the Director 
of the Office of the Federal Register under 5 U.S.C. 552(a) and 1 CFR 
part 51. All approved materials are available for inspection at the 
FAA's Office of Rulemaking (ARM-1), 800 Independence Avenue, SW., 
Washington, DC 20590 (telephone 202-267-9677), or at the National 
Archives and Records Administration (NARA). For information on the 
availability of this material at NARA, call 202-741-6030, or go to 
http://www.archives.gov/federal_register/code_of_federal_ 
regulations/ibr_locations.html. This material is also available from 
the sources indicated in paragraphs (g)(1) and (g)(2) of this section.
    (1) Copies of Technical Standard Order (TSO)-C166b, Extended 
Squitter Automatic Dependent Surveillance-Broadcast (ADS-B) and Traffic 
Information Service-Broadcast (TIS-B) Equipment Operating on the Radio 
Frequency of 1090 Megahertz (MHz) (December 2, 2009) and TSO-C154c, 
Universal Access Transceiver (UAT) Automatic Dependent Surveillance-
Broadcast (ADS-B) Equipment Operating on the Frequency of 978 MHz 
(December 2, 2009) may be obtained from the U.S. Department of 
Transportation, Subsequent Distribution Office, DOT Warehouse M30, 
Ardmore East Business Center, 3341 Q 75th Avenue, Landover, MD 20785; 
telephone (301) 322-5377. Copies of TSO -C166B and TSO-C154c are also 
available on the FAA's Web site, at http://www.faa.gov/aircraft/air_
cert/design_approvals/tso/. Select the link ``Search Technical 
Standard Orders.''
    (2) Copies of Section 2, Equipment Performance Requirements and 
Test Procedures, of RTCA DO-260B, Minimum Operational Performance 
Standards for 1090 MHz Extended Squitter Automatic Dependent 
Surveillance-Broadcast (ADS-B) and Traffic Information Services-
Broadcast (TIS-B), December 2, 2009 (referenced in TSO-C166b) and 
Section 2, Equipment Performance Requirements and Test Procedures, of 
RTCA DO-282B, Minimum Operational Performance Standards for Universal 
Access Transceiver (UAT) Automatic Dependent Surveillance-Broadcast 
(ADS-B), December 2, 2009 (referenced in TSO C-154c) may be obtained 
from RTCA, Inc., 1828 L Street, NW., Suite 805, Washington, DC 20036-
5133, telephone 202-833-9339. Copies of RTCA DO-260B and RTCA DO-282B 
are also available on RTCA Inc.'s Web site, at http://www.rtca.org/
onlinecart/allproducts.cfm.
    9. Amend appendix D to part 91 by revising section 1 introductory 
text to read as follows:

APPENDIX D TO PART 91--AIRPORTS/LOCATIONS: SPECIAL OPERATING 
RESTRICTIONS

    Section 1. Locations at which the requirements of Sec.  
91.215(b)(2) and Sec.  91.225(d)(2) apply. The requirements of 
Sec. Sec.  91.215(b)(2) and 91.225(d)(2) apply below 10,000 feet 
above the surface within a 30-nautical-mile radius of each location 
in the following list.
* * * * *

    Issued in Washington, DC, on May 21, 2010.
J. Randolph Babbitt,
Administrator.
[FR Doc. 2010-12645 Filed 5-27-10; 8:45 am]
BILLING CODE 4910-13-P

