
[Federal Register Volume 79, Number 158 (Friday, August 15, 2014)]
[Proposed Rules]
[Pages 48098-48105]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-18959]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Parts 25, 121, and 129

[Docket No.: FAA-2014-0500; Notice No. 14-07]
RIN 2120-AK30


Fuel Tank Vent Fire Protection

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This action would amend certain airworthiness regulations for 
transport category airplanes to require fuel tank designs that prevent 
a fuel tank explosion caused by flame propagation through the fuel tank 
vents from external fires. This action would add a new requirement for 
fuel tank vent fire protection and would increase the time available 
for passenger evacuation and emergency response. This proposed 
amendment would apply to applications for new type certificates and 
certain applications for amended or supplemental type certificates. It 
would also require certain airplanes produced in the future and 
operated by air carriers to meet the new standards.

DATES: Send comments on or before November 13, 2014.

ADDRESSES: Send comments identified by docket number FAA-2014-0500 
using any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov and follow the online instructions for sending your 
comments electronically.
     Mail: Send comments to Docket Operations, M-30; U.S. 
Department of Transportation (DOT), 1200 New Jersey Avenue SE., Room 
W12-140, West Building Ground Floor, Washington, DC 20590-0001.
     Hand Delivery or Courier: Take comments to Docket 
Operations in Room W12-140 of the West Building Ground Floor at 1200 
New Jersey Avenue SE., Washington, DC, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
     Fax: Fax comments to Docket Operations at 202-493-2251.
    Privacy: The FAA will post all comments it receives, without 
change, to http://www.regulations.gov, including any personal 
information the commenter provides. Using the search function of the 
docket Web site, anyone can find and read the electronic form of all 
comments received into any FAA docket, including the name of the 
individual sending the comment (or signing the comment for an 
association, business, labor union, etc.). DOT's complete Privacy Act 
Statement can be found in the Federal Register published on April 11, 
2000 (65 FR 19477-19478), as well as at http://DocketsInfo.dot.gov.
    Docket: Background documents or comments received may be read at 
http://www.regulations.gov at any time. Follow the online instructions 
for accessing the docket or go to the Docket Operations in Room W12-140 
of the West Building Ground Floor at 1200 New Jersey Avenue SE., 
Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, 
except federal holidays.

FOR FURTHER INFORMATION CONTACT: For technical questions concerning 
this action, contact Mike Dostert, Propulsion and Mechanical Systems 
Branch, ANM-112, Transport Airplane Directorate, Aircraft Certification 
Service, Federal Aviation Administration, 1601 Lind Ave. SW., Renton, 
WA 98057-3356; telephone (425) 227-2132; facsimile (425) 227-1149; 
email Mike.Dostert@faa.gov.
    For legal questions concerning this action, contact Sean Howe, 
Office of the Regional Counsel, ANM-7, Federal Aviation Administration, 
1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone (425) 
227-2591; facsimile (425) 227-1007; email Sean.Howe@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. 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 III, Section 44701, ``General 
Requirements.'' Under that section, the FAA is charged with promoting 
safe flight of civil aircraft in air commerce by prescribing 
regulations and minimum standards for the design and performance of 
aircraft that the Administrator finds necessary for safety in air 
commerce. This regulation is within the scope of that authority. It 
prescribes new safety standards for the design and operation of 
transport category airplanes.

I. Overview of Proposed Rule

A. General

    This proposed rule would prevent fuel tank explosions caused by 
ignition (from potential external ignition sources) of fuel vapor 
present in or exiting through the fuel tank vent outlets. Ignition 
sources may include, but are not limited to, ground handling equipment, 
fuel fires that result from refueling spills, or ground fire that may 
be present following a survivable crash landing in which the fuel tank 
and the vent system remain intact. The FAA has determined that a means 
to prevent propagation of flame \1\ from external sources into the tank 
through the fuel tank vents, such as flame arrestors or a means of 
inerting the fuel tanks, could be used to prevent or delay fuel tank 
explosions following certain accidents. This prevention or delay would 
provide time for the safe evacuation of passengers from the airplane.
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    \1\ Flame propagation is defined as the spread of a flame in a 
combustible environment outward from the point at which the 
combustion started.
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    This proposed rule would apply to applications for new type 
certificates and applications for amended or supplemental type 
certificates on significant product level change projects in which 
Title 14, Code of Federal Regulations (14 CFR) 25.975, Fuel tank vents 
and carburetor vapor vents, is applicable to a changed area. We are 
also proposing a new operating requirement applicable to newly produced 
airplanes that are issued an original airworthiness certificate after a 
specified date, per 14 CFR part 121, Operating Requirements: Domestic, 
Flag, and Supplemental Operations, and 14 CFR part 129, Operations: 
Foreign Air Carriers and Foreign Operators of U.S.-Registered Aircraft 
Engaged in Common Carriage. We do not propose to require retrofit of 
the existing fleet.
    Currently, there is not an advisory circular (AC) that describes 
compliance means for protection of fuel tank vents from external 
ignition sources. We have provided compliance means information to 
applicants for type certificates through project-specific issue papers. 
These issue papers describe how to demonstrate that flame will not 
progress through the fuel tank vents into the fuel tank.
    Concurrent with the publication of this proposal, we are also 
publishing for

[[Page 48099]]

comment an associated draft AC 25.975-X that will provide applicants 
with one acceptable means of compliance for preventing propagation of 
flames through the fuel tank vents.

B. Total Costs and Benefits of This Proposed Rule

    The FAA finds the proposed rule to be cost-beneficial because the 
costs of the rule are low enough that the expected benefits of 
preventing just two fatalities would outweigh the expected costs ($4.9 
million in present value benefits versus $4.4 million in present value 
costs). If this action is not taken, a hazard would continue to exist 
even though effective and low-cost means are available to minimize or 
eliminate it.

II. Background

A. Statement of the Problem

    Fires outside of the airplane fuel tanks can be caused by events 
such as fuel spilled during refueling, fuel and oil spillage following 
survivable accidents from engines that separate from the airplane, or 
leaking airplane fuel tanks. In some cases, external fires have ignited 
fuel vapors that exit the fuel tank vents, resulting in flames 
traveling through the vent lines into the fuel tank, causing fuel tank 
explosions. These explosions have caused fatalities to passengers and 
have prevented emergency personnel from assisting survivors.
    During an industry review of potential post-crash survivability, 
the Special Aviation Fire and Explosion Reduction (SAFER) Advisory 
Committee \2\ determined that four fuel tank explosions resulting from 
post-crash fires could have been avoided if flame arrestors or surge 
tank explosion suppression systems \3\ had been installed in the 
airplane fuel tank vents \4\. The SAFER committee examined methods of 
preventing fuel tank explosions following impact survivable accidents. 
Options included controlling the fuel tank flammability using nitrogen 
inerting systems, using fire suppression systems, and installation of 
flame arrestors.
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    \2\ Special Aviation Fire and Explosion Reduction (SAFER) 
Advisory Committee final report, volume 1, FAA/AFS-80-4 dated June 
26, 1973, through June 26, 1980.
    \3\ Surge tank explosion suppression systems were installed on 
some Boeing airplanes to prevent a lightning strike from igniting 
fuel vapor in the fuel tank vent system. These systems used light 
sensors that activated the discharge of fire suppression agent into 
the fuel tank vent surge tank to prevent the fire from traveling 
through the vents into the airplane fuel tanks.
    \4\ SAFER Report, page 49, Figure 3.
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    The SAFER committee determined the most practical means of 
preventing post-crash fuel tank explosions was the use of flame 
arrestors. Flame arrestors or suppression systems delay propagation of 
ground fires into the fuel tank and the subsequent explosions, 
providing additional time for the safe evacuation of passengers. Flame 
arrestors stop the flame from traveling through the fuel tank vents by 
quenching the flame. Flame arrestors are typically made of numerous 
small stainless steel passages that remove heat from the flame so it 
dies out before passing through the vent. Flame arrestors for a typical 
transport airplane range in weight from 2 to 4 pounds each.
    The current airworthiness standards related to fuel system 
explosion prevention in 14 CFR 25.981 include requirements to prevent 
ignition inside the fuel tanks caused by system failures or external 
heating of the fuel tank walls. The fuel tank venting standards also 
include requirements to ensure fuel tank structural integrity following 
failures of the refueling system that could result in overfilling of 
the fuel tanks or clogging of the vents due to ice. Additionally, Sec.  
25.954, Fuel system lightning protection, requires fuel tank vents be 
designed and arranged to prevent the ignition of fuel vapor within the 
system by lightning strikes.

B. History

    In 1995, based on the SAFER Committee report noted above, the FAA 
issued the notice of proposed rulemaking (NPRM) entitled, ``Fuel System 
Vent Fire Protection,'' (60 FR 6632), dated February 2, 1995. This 
notice proposed a requirement for fuel tank vent fire protection in new 
type design transport airplanes and retrofit of the existing fleet of 
transport category airplanes through an amendment of operating rules. 
Comments received in response to the notice questioned the accuracy of 
the FAA's economic analysis related to the proposed retrofit 
requirement. Comments also indicated that additional guidance, in the 
form of an AC, should be developed to provide an acceptable means to 
qualify flame arrestors to meet the proposed requirement.
    To address these issues, the FAA obtained additional cost 
information from component suppliers and developed an AC that included 
means of compliance. In 2001, the FAA tasked the Aviation Rulemaking 
Advisory Committee (ARAC) to review the draft final rule, including the 
FAA's proposed disposition of public comments, and to review the draft 
AC. Due to the ARAC tasking, on August 23, 2002 the FAA published a 
notice in the Federal Register of withdrawal of the ``Fuel System Vent 
Protection'' NPRM published in 1995. As a result of industry resource 
issues and FAA rulemaking prioritization activities, no work was done 
on these ARAC taskings. The FAA published a withdrawal of the tasks on 
June 21, 2004.
    As a result of limited ARAC resources, the FAA developed a strategy 
for a number of rulemaking projects that had been tasked to ARAC and 
issued a letter \5\ dated June 14, 2005, to the head of the Transport 
Airplane and Engine Issues Group describing our intent to use the 
existing 14 CFR 21.21 (finding an ``unsafe design feature'') to address 
the need for flame arrestors in the fuel tank vents. Since 2005, this 
has resulted in new type certificated airplanes having flame arrestors.
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    \5\ Hickey, John. Letter to Craig Bolt. 14 June 2005.
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    Prior to issuance of the letter in 2005, following industry 
recommendations, many manufacturers voluntarily introduced flame 
arrestors into their new type designs. Currently, most new type designs 
and most newly produced transport category airplanes incorporate flame 
arrestors in the fuel tank vents. Additionally, several applicants have 
installed fuel tanks in the airplane fuselage that have vents located 
in areas prone to lightning strikes (defined as zone 2), such that 
flame arrestors were provided to prevent flame propagation into the 
fuel tanks to comply with Sec.  25.954.
    However, some models of newly manufactured airplanes produced under 
older type certificates, including business jets and smaller transport 
category airplanes, do not incorporate a means to prevent flame 
propagation through the fuel vent lines to the fuel tanks. Airplanes in 
14 CFR part 121 operation that do not have such a means include older 
models like the DC-9, MD-80, as well as all past and currently produced 
DHC-8 turboprops, and Canadair Regional Jets.
    As a result of the review of several fuel tank explosions on older 
designs, including a Philippine Airlines Boeing 737,\6\ the FAA issued 
an airworthiness directive (AD) for Boeing Model 737 airplanes 
mandating incorporation of flame arrestors.\7\ Early models of the 737 
did not have means to prevent propagation of a flame from the fuel tank 
vent outlet into the fuel tanks. The Philippine explosion occurred 
while the airplane was parked at the gate. The ignition source that 
caused the explosion could not be determined.

[[Page 48100]]

However, external ignition sources such as ground handling equipment or 
hot surfaces on lighting located near the vent outlet were evaluated as 
the possible source of the ignition.
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    \6\ On May 11, 1990, a Philippine Airlines 737-300 was destroyed 
by a fuel tank explosion on the apron at Manila Ninoy Aquino 
International Airport.
    \7\ AD 99-03-04 BOEING: Amendment 39-11018; Docket 98-NM-50-AD; 
effective March 9, 1999.
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    In addition to the 737 AD, we have issued other ADs to either 
require flame arrestors or verify their functionality on the Lockheed 
Model 1649A piston airplane,\8\ Boeing Models 707 and 720,\9\ the Beech 
Model 400A,\10\ and the Lockheed Model 382.\11\
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    \8\ AD 59-20-02 LOCKHEED: Effective October 15, 1959, for items 
(1) and (2) and December 1, 1959, for item (3).
    \9\ AD 67-23-02 BOEING: Amendment 39-462. Effective September 
10, 1967.
    \10\ AD 92-16-14 BEECH: Amendment 39-8323; Docket No. 92-NM-95-
AD; effective September 1, 1992.
    \11\ AD 2011-15-02 LOCKHEED: Amendment 39-16749; Docket No., 
FAA-2010-1305; effective August 19, 2011.
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    Since 2005, the FAA has also addressed the possibility of fuel tank 
ignition resulting from post-crash fire propagation through fuel vent 
lines with issue papers applied to specific certification projects.
    However, the lack of a specific part 25 regulation has resulted in 
some manufacturers completing initial airplane designs and applying for 
a U.S. type certificate without considering the need to mitigate the 
risk of flame propagation through fuel vent lines. Some newly 
manufactured airplanes introduced into the U.S. fleet do not have flame 
arrestors in the fuel tank vents.\12\
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    \12\ Bombardier Q400 (Dash 8) and Canadair Regional Jets.
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III. Discussion of the Proposal

A. General

    This proposal would establish a minimum time period for preventing 
a fuel tank explosion caused by flame propagation through the fuel tank 
vents of 2 minutes and 30 seconds, measured from the time a flame first 
impinges on any fuel tank vent. This capability would allow time to 
evacuate passengers and crew to a safe distance from the airplane and 
for emergency response to begin. The minimum performance standard in 
this proposal is based on a balance between the available technology, 
practicality considerations, and providing a satisfactory passenger 
evacuation safety standard.
    The proposed regulatory text is intended to prevent, or at least 
delay, fuel tank explosions or fires caused by external fires that 
ignite fuel or vapor in the fuel tank. External fires may be caused by 
sources such as post-crash ground fires, fires resulting from fuel 
leakage during refueling, and ignition of fuel exiting the fuel vents. 
The proposal requires consideration of flames in the fuel tank vent 
outlets including propagation through the vent line, as well as 
ignition sources created by damage to the vent system caused by the 
external fire, such as burn-through of fuel tank vent system components 
or heating of the vent system components.
    To limit propagation of external fires through the vent system, it 
is necessary to design a flame arrestor, a flame suppression device, or 
other system to prevent flame penetration and propagation through the 
airplane fuel tank vents. The minimum time period should be no less 
than the time required to evacuate the airplane. The FAA has previously 
established a performance standard that, under specified conditions, 
the airplane must be capable of being evacuated within 90 seconds 
(Sec.  25.803, Emergency evacuation). The conditions under which the 
airplane is evacuated assume availability of a minimum number of exits 
and all passengers are uninjured and physically capable of departing 
the airplane. This is not always the case.
    In addition to time for evacuation of passengers, we have also 
established minimum standards for penetration of a fuel fire through 
the airplane fuselage to allow emergency crews time to arrive at an 
accident and to establish control of a fire (Sec.  25.856, Thermal/
Acoustic insulation materials). Analysis of past accidents showed the 
greatest benefits when a minimum of 5 minutes is provided. This time 
includes 1 minute for a fire to penetrate the fuselage skin and an 
additional 4 minutes for the fire to burn through the insulation. The 
time of 5 minutes for penetration of a post-crash ground fire into the 
fuselage was based on research into studies of past accidents.\13\ \14\ 
As part of a project commissioned by the FAA, data have been gathered 
on the relative proportion of accidents that involve ground pooled fuel 
fires and statistical data on the following:
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    \13\ DOT/FAA/AR-99/57, Fuselage Burnthrough Protection for 
Increased Postcrash Occupant Survivability: Safety Benefit Analysis 
Based on Past Accidents, September 1999.
    \14\ DOT/FAA/AR-09/18, Determination of Evacuation and 
Firefighting Times Based on an Analysis of Aircraft Accident Fire 
Survivability Data, May 2009.
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     Time to initiate an evacuation;
     Time to complete an evacuation;
     Time to arrival of fire-fighters; and
     Time for fire-fighters to establish control in a ground 
pool fire accident.
    The data were extracted from accident reports and other information 
published by investigating and airworthiness authorities using the 
Cabin Safety Research Technical Group aircraft accident database.
    Current technology flame arrestors installed in the transport fleet 
have been designed to have a capability to prevent flame propagation 
into the fuel tanks for up to 2 minutes and 30 seconds after flame 
enters the fuel tank vent and contacts the face of the flame arrestor.
    The FAA is proposing a minimum standard of 2 minutes and 30 
seconds. This time is greater than the 90 second evacuation time noted 
above and allows additional time for passengers to exit from the crash 
scene. No adverse service experience has occurred on airplanes equipped 
with flame arrestors that provide this amount of time. While this time 
is less than the 5 minute test standard required by Sec.  25.856 for a 
ground fire to penetrate into the fuselage, the FAA has determined 
providing fuel tank vent protection in excess of 2 minutes and 30 
seconds would not be practical. Comments received to the notice issued 
in 1995 indicated flame arrestors that meet a 5 minute standard would 
need to be significantly larger, weigh more, and would introduce 
significant pressure loss in the fuel system vent line, resulting in 
the need to increase the size of the vent line to meet airplane 
refueling performance requirements.

B. Potential for Blockage of Vents

    During the approval process for the existing compliance means that 
use flame arrestors in the vent lines, several applicants expressed 
concerns that requiring flame arrestors may reduce the level of safety 
due to restrictions being introduced into the vents. The FAA 
acknowledges that introducing flame arrestors in the fuel tank vents 
may introduce the potential for clogging of the vent lines from ice and 
debris. This could result in adverse consequences like more severe tank 
pressures during fueling/over-fueling, greater differential pressures 
on the tank skins during emergency descent or defueling, reduced fuel 
jettison capability, and an increased risk of vent system blockage.
    To address these design considerations, applicants have included 
positive and negative pressure relief provisions in their vent system 
designs. This has afforded an excellent safety record. Service 
experience of thousands of airplanes in the current fleet equipped with 
flame arrestors indicates that each of these concerns (and other such 
concerns not listed above) can be safely mitigated with proper design 
and certification of the fuel tank vent fire protection. Proposed

[[Page 48101]]

AC 25.975-X would provide the guidance necessary to address these 
issues.

C. Revise ``Fuel Tank Vents and Carburetor Vapor Vents'' (Sec.  25.975)

    Section 25.975 currently prescribes standards for fuel tank vents 
but does not contain a standard for protecting the fuel tanks from 
external flame propagating into the tank. We propose to add a new 
paragraph, Sec.  25.975(a)(7), to establish a requirement for a means 
to prevent the propagation of flames, for a limited time, from outside 
the fuel tank through the fuel tank vents that could cause a fuel tank 
explosion.
    Means of compliance available today include incorporation of flame 
arrestors in the fuel system vent lines. Other means that might be 
available in the future include full time fuel tank inerting systems 
that prevent fuel tank explosions due to post-crash or other external 
fires.
    We considered alternative technical solutions, such as mandating 
nitrogen inerting systems that would prevent a fuel tank explosions 
caused by external fires by eliminating fuel tank flammability. Current 
fuel tank flammability limits in Sec.  25.981 have resulted in the use 
of nitrogen inerting systems in some or all fuel tanks. However, the 
fuel tanks become flammable during certain portions of airplane 
operations such as during fuel tank refueling and times when the 
inerting system cannot produce enough nitrogen to inert the fuel tanks. 
During these times, the tanks continue to be vulnerable to explosion 
from flame propagation through fuel system vent lines. The cost to 
incorporate full-time nitrogen inerting systems in all fuel tanks would 
be excessive.
    Another alternative we considered was to continue using 
certification project-specific issue papers to address fuel tank vent 
fire protection. However, this alternative does not allow public review 
and comment and does not result in broad industry awareness of the need 
to incorporate vent system protection into new designs early in the 
airplane design process. In addition, this method is more costly and 
time consuming for both the FAA and applicants due to the need to 
process an issue paper identifying specific requirements for each 
project. Some applicants have objected to this approach, and it has 
proven more difficult to apply in a standardized manner.
    After considering these alternatives, we have concluded that the 
most practical and cost effective method to address this safety issue 
is the incorporation of flame arrestors in the fuel system vent lines 
(as recommended in the SAFER committee report).

D. Newly Produced Airplanes

    Parts 121 and 129 prescribe operating requirements for air 
carriers, including requirements for the airworthiness of each 
airplane. Part 121 applies to domestic operators and, for airworthiness 
requirements, part 129 applies to foreign operators operating U.S.-
registered airplanes. We propose to add a new operating requirement 
that would apply to newly manufactured airplanes entering service 2 
years after the effective date of this proposed regulation. This 
compliance time is based on the estimated time needed to design and 
develop a flame arrestor installation for existing airplanes. Flame 
arrestor technology is currently available, and adaptation of this 
technology to currently produced airplanes, certifying the design and 
incorporation of the design in production, should be achievable within 
the 2-year compliance time.
    While this proposal does not require manufacturers of existing type 
designs to develop design features meeting the requirements, we 
anticipate operators of the affected airplane models will enter into 
business agreements with manufacturers to provide compliant designs 
that meet the proposed operating regulations. Newly manufactured 
airplanes that enter service typically have a minimum operating life of 
20 years in passenger service. Therefore, the safety benefits of 
incorporating flame arrestors would be greatest in newly produced 
airplanes entering service.
    We are not proposing a requirement to retrofit airplanes in the 
current fleet. This decision was based on the determination that many 
of the older airplane models that do not have flame arrestors are being 
retired. The cost to retrofit these airplanes for the safety 
improvement is not in the public interest.

IV. Regulatory Notices and Analyses

A. Regulatory Evaluation

    Changes to Federal regulations must undergo several economic 
analyses. First, Executive Order 12866 and Executive Order 13563 direct 
that each Federal agency shall 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, the 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 
base year of 1995). This portion of the preamble summarizes the FAA's 
analysis of the economic impacts of the proposed rule. We suggest 
readers seeking greater detail read the full regulatory evaluation, a 
copy of which we have placed in the docket for this rulemaking.
    In conducting these analyses, FAA has determined that this proposed 
rule: (1) Has benefits that justify its costs; (2) is not an 
economically ``significant regulatory action'' as defined in section 
3(f) of Executive Order 12866; (3) is not ``significant'' as defined in 
DOT's Regulatory Policies and Procedures; (4) would not have a 
significant economic impact on a substantial number of small entities; 
(5) would not create unnecessary obstacles to the foreign commerce of 
the United States; and (6) would not impose an unfunded mandate on 
state, local, or tribal governments, or on the private sector by 
exceeding the threshold identified above.
    These analyses are summarized below.
Total Costs and Benefits of This Proposed Rule
    The FAA finds the proposed rule to be cost-beneficial because the 
costs of the rule are low enough that the expected benefits of 
preventing just two fatalities would outweigh the expected costs ($4.9 
million in present value benefits versus $4.4 million in present value 
costs). If this action is not taken, a hazard would continue to exist 
even though effective and low-cost means are available to minimize or 
eliminate it.
Who is potentially affected by this rule?
    Manufacturers of newly certified part 25 airplanes and U.S. 
operators of these airplanes are affected by the rule as a result of 
its applicability to new certification part 25 airplanes. Manufacturers 
and operators of

[[Page 48102]]

currently produced part 25 airplanes (production cut-in) are affected 
by the rule as a result of its applicability to airplanes engaged in 
part 121 or 129 operations produced two years or more after the 
effective date of this rule.
Principal Assumptions and Sources of Information
     Discount rate is 7 percent (Office of Management & Budget, 
Circular A-94, ``Guidelines and Discount Rates for Benefit-Cost 
Analysis of Federal Programs,'' October 29, 1992, p. 8).
     Value of statistical life (VSL) begins at $9.1 million in 
2012 and increases thereafter by an annual growth factor of 1.0107. 
Memorandum: Guidance on Treatment of the Economic Value of a 
Statistical Life in Department Analyses. [February 2013]. United 
States, Office of the Secretary of Transportation.
     For small part 25 manufacturers: Two U.S. airplane 
certifications in next 10-year period, twenty-one annual U.S. 
deliveries per U.S. certification; three foreign airplane 
certifications in next 10-year period, eleven annual U.S. deliveries 
per foreign certification, 15-year airplane production run; 30-year 
retirement age. Internal FAA study.
     Current airplane models that could be affected by 
production cut-in requirement (Bombardier Dash 8, CJ-700, and CJ-900): 
FAA 2013 Fleet Forecast, Fleet Forecast Sheet, ``FAA U.S. Airlines 
2013-2013 1-18-2103,'' ``Totals & FAA Tables.''
     The period of analysis for new certifications is 45 years 
to account for a complete product life cycle determined by a 15-year 
production period and a 30-year service period.
     Certification cost estimates for part 25 airplanes--Survey 
of small U.S. part 25 airplane manufacturers.
     Maintenance cost per airplane (every four years) for 
Bombardier CJ-700/CJ-900 regional jets (subject to production cut-in)--
$240. This estimate is much lower than the U.S. estimate because it is 
for passenger airplane models, while the U.S. estimate is for business 
jet models. Since business jets are more prone to sit for extended 
periods of time, their flame arrestors can more easily be clogged by 
ice, mud daubers, or other debris, thus requiring more frequent and 
longer maintenance.
     Minimal fuel costs as flame arrestors weigh between 2 and 
4 pounds each.
Costs of This Proposed Rule
    The costs of the proposed rule are engineering, production, and 
maintenance compliance costs for newly certificated part 25 airplanes 
and for new production of currently-produced part 25 airplanes used in 
part 121 operations (production cut-in). We first estimate compliances 
costs for new certifications and then for the production cut-in.
Compliance Costs of New Certification Airplanes to Manufacturers and 
Operators
    For newly certificated airplanes, compliance costs consist of 
engineering and production costs of U.S. manufactured airplanes 
delivered to U.S. operators and maintenance costs of both U.S. and 
foreign airplanes delivered to U.S. operators. U.S. part 25 
manufacturers directly incur the engineering and production costs while 
U.S. operators directly incur the maintenance costs. Engineering and 
production costs incurred by foreign manufacturers are not included in 
the costs of compliance, as costs directly attributable to foreign 
entities are not included in the cost and benefit analysis of proposed 
U.S. regulations.
    To calculate the cost of new U.S. certifications, we assume that 
all new certifications will be approved one year after the effective 
date of the rule, with production beginning one year later. Using an 
airplane life cycle model, we estimate the economic impact for two new 
certificates, production of 21 airplanes/certificates/year, production 
runs of 15 years, and an airplane retirement age of 30 years. 
Compliance costs per year are calculated over an airplane life cycle of 
45 years.
    Industry cost estimates were solicited from small part 25 
manufacturers because large airplane manufacturers (Boeing and Airbus) 
are already compliant with the proposed rule. These cost estimates are 
shown in the table below.


  Industry Cost Estimates Using Flame Arrestors To Comply With Proposed
                                  Rule
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           Cost category                 Cost              Notes
------------------------------------------------------------------------
Nonrecurring Engineering Costs.....     $142,000  per model.
Production Costs (Hardware &               3,000  per airplane (two
 Installation).                                    flame arrestors
                                                   @$1,500 each).
Maintenance Costs (U.S.                      415  per airplane annually.
 manufacturers).
Maintenance Costs (Bombardier).....          240  per airplane every 4
                                                   years.
------------------------------------------------------------------------

    The industry cost estimates consist of nonrecurring (one-time) 
engineering costs, production costs for two flame arrestors per 
airplane (one per fuel tank), and maintenance costs per airplane per 
year. (The Bombardier maintenance cost estimate is used for estimating 
production cut-in costs of compliance.) Incorporating the industry cost 
estimates into the airplane life cycle model, we find total costs for 
new certification airplanes to be $16.2 million with present value of 
$4.2 million. $2.2 million of these costs (present value $1.2 million) 
are directly incurred by U.S. manufacturers and $14.0 million (present 
value $2.1 million) are directly incurred by U.S. operators.\15\
---------------------------------------------------------------------------

    \15\ Details may not sum to totals due to rounding.
---------------------------------------------------------------------------

Compliance Costs of Production Cut-In
    In addition to the requirement applying to new certifications, the 
proposed rule would also require a production cut-in for currently 
produced part 25 airplanes used in part 121 operations.\16\ To 
calculate this cost, we first note that the only currently produced and 
U.S. operated airplane models not already in compliance are the 
Bombardier Dash 8 turboprops and Bombardier CJ-700/CJ-900 regional 
jets. The final rule would apply to these Bombardier models produced 
beginning in 2018. Since the FAA forecasts no Dash 8 deliveries to U.S. 
airline operators after 2017, we expect no Dash 8 compliance cost for 
these operators.
---------------------------------------------------------------------------

    \16\ We do not estimate costs for the analogous part 129 
requirement as these costs are directly incurred by foreign 
operators.
---------------------------------------------------------------------------

    The FAA does forecast the delivery of 338 CRJ-700 and 161 CRJ-900 
model airplanes to U.S. airline operators over the period 2018-2033. 
The engineering and production compliance costs for these airplanes are 
not included in our cost estimates because, as noted above, costs 
directly incurred by foreign entities are not included in the cost and

[[Page 48103]]

benefit analysis of proposed U.S. regulations. Accordingly, for these 
airplanes we assess the impact on U.S. operators only, using 
Bombardier's maintenance cost estimate of $240 every four years. 
Allocating this cost as $60 annually and assuming a production period 
of 16 years, we calculate the maintenance costs for these airplanes 
from the first year of service to the retirement year of the last 
airplanes produced, using a procedure analogous to that used for new 
certification airplanes. We find these costs to operators to be 
$898,200 with present value $178,439.
    Production cut-in costs of $898,200 (present value $178,439) added 
to new certification airplane costs of $16.2 million (present value 
$4.2 million) yield total rule costs of $17.1 million (present value 
$4.4 million).
Benefits of This Proposed Rule
    Notwithstanding the absence of post-crash fuel tank explosions in 
recent years and lacking other sufficient bases upon which to estimate 
future risks, the merits of the proposed rule can be assessed by 
considering the number of fatalities that would need to be prevented to 
offset the costs of the rule.
    We estimate the breakeven benefits of the rule by estimating the 
number of averted fatalities necessary to offset the $4.4 million 
present value costs of the rule. We find that just two averted 
fatalities would offset these estimated costs.

B. Regulatory Flexibility Determination

    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 it 
will, the agency must prepare a regulatory flexibility analysis as 
described in the RFA.
    However, if an agency determines that a rule is not expected to 
have a significant economic impact on a substantial number of small 
entities, section 605(b) of the RFA provides that the head of the 
agency may so certify and a regulatory flexibility analysis is not 
required. The certification must include a statement providing the 
factual basis for this determination, and the reasoning should be 
clear.
    All small U.S. manufacturers affected by this rule are wholly owned 
subsidiaries of large companies, who have more than 1,500 employees 
(the small business criterion for aircraft manufacturing) and, 
therefore, are not classified as small entities by the Small Business 
Administration. Part 121 operators would be directly affected by the 
average $415 annual maintenance cost per airplane. These costs are 
minimal, especially compared to the high cost of new part 25 airplanes.
    If an agency determines that a rulemaking will not result in a 
significant economic impact on a substantial number of small entities, 
the head of the agency may so certify under section 605(b) of the RFA. 
Therefore, as provided in section 605(b), the head of the FAA certifies 
that this rulemaking would not result in a significant economic impact 
on a substantial number of small entities.
    The FAA solicits comments regarding this determination.

C. International Trade Impact Assessment

    The Trade Agreements Act of 1979 (Public Law 96-39), as amended by 
the Uruguay Round Agreements Act (Public Law 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 as 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.
    This proposed rule would not create an unnecessary obstacle to 
foreign commerce as foreign and domestic manufacturers are equally 
affected and its effect on part 121 operators would be domestic only.

D. Unfunded Mandates Assessment

    Title II of the Unfunded Mandates Reform Act of 1995 (Public Law 
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 $151.0 million in lieu of $100 
million. This proposed rule does not contain such a mandate; therefore, 
the requirements of Title II of the Act do not apply.

E. Paperwork Reduction Act

    The Paperwork Reduction Act of 1995 (44 U.S.C. 3507(d)) requires 
that the FAA consider the impact of paperwork and other information 
collection burdens imposed on the public. The FAA has determined that 
there would be no new requirement for information collection associated 
with this proposed rule.

F. International Compatibility and Cooperation

    In keeping with U.S. obligations under the Convention on 
International Civil Aviation, it is FAA policy to conform to 
International Civil Aviation Organization (ICAO) Standards and 
Recommended Practices to the maximum extent practicable. The FAA has 
determined that there are no ICAO Standards and Recommended Practices 
that correspond to these proposed regulations.

G. Environmental

    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 this rulemaking action qualifies for the categorical 
exclusion identified in paragraph 312f and involves no extraordinary 
circumstances.

V. Executive Order Determinations

A. Executive Order 13132, Federalism

    The FAA has analyzed this proposed rule under the principles and 
criteria of Executive Order 13132, Federalism. The agency has 
determined that this action would 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,

[[Page 48104]]

therefore, would not have Federalism implications.

B. Executive Order 13211, Regulations That Significantly Affect Energy 
Supply, Distribution, or Use

    The FAA analyzed this proposed rule under Executive Order 13211, 
Actions Concerning Regulations that Significantly Affect Energy Supply, 
Distribution, or Use (May 18, 2001). The agency has determined that it 
would not be a ``significant energy action'' under the executive order 
and would not be likely to have a significant adverse effect on the 
supply, distribution, or use of energy.

VI. Additional Information

A. Comments Invited

    The FAA invites interested persons to participate in this 
rulemaking by submitting written comments, data, or views. The agency 
also invites comments relating to the economic, environmental, energy, 
or federalism impacts that might result from adopting the proposals in 
this document. The most helpful comments reference a specific portion 
of the proposal, explain the reason for any recommended change, and 
include supporting data. To ensure the docket does not contain 
duplicate comments, commenters should send only one copy of written 
comments, or if comments are filed electronically, commenters should 
submit only one time.
    The FAA will file in the docket all comments it receives, as well 
as a report summarizing each substantive public contact with FAA 
personnel concerning this proposed rulemaking. Before acting on this 
proposal, the FAA will consider all comments it receives on or before 
the closing date for comments. The FAA will consider comments filed 
after the comment period has closed if it is possible to do so without 
incurring expense or delay. The agency may change this proposal in 
light of the comments it receives.
    Proprietary or Confidential Business Information: Commenters should 
not file proprietary or confidential business information in the 
docket. Such information must be sent or delivered directly to the 
person identified in the FOR FURTHER INFORMATION CONTACT section of 
this document, and marked as proprietary or confidential. If submitting 
information on a disk or CD ROM, mark the outside of the disk or CD 
ROM, and identify electronically within the disk or CD ROM the specific 
information that is proprietary or confidential.
    Under 14 CFR 11.35(b), if the FAA is aware of proprietary 
information filed with a comment, the agency does not place it in the 
docket. It is held in a separate file to which the public does not have 
access, and the FAA places a note in the docket that it has received 
it. If the FAA receives a request to examine or copy this information, 
it treats it as any other request under the Freedom of Information Act 
(5 U.S.C. 552). The FAA processes such a request under Department of 
Transportation procedures found in 49 CFR part 7.

B. Availability of Rulemaking Documents

    An electronic copy of rulemaking documents may be obtained from the 
Internet by:
    1. Searching the Federal eRulemaking Portal (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.gpo.gov/fdsys/.
    Copies may also be obtained 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. 
Commenters must identify the docket or notice number of this 
rulemaking.
    All documents the FAA considered in developing this proposed rule, 
including economic analyses and technical reports, may be accessed from 
the Internet through the Federal eRulemaking Portal referenced in item 
1 above.

List of Subjects

14 CFR Part 25

    Aircraft, Aviation safety, Life-limited parts, Reporting and 
recordkeeping requirements.

14 CFR Part 121

    Air carriers, Aircraft, Aviation safety, Reporting and 
recordkeeping requirements, Safety, Transportation.

14 CFR Part 129

    Air carriers, Aircraft, Aviation safety, Reporting and 
recordkeeping requirements.

The Proposed Amendment

    In consideration of the foregoing, the Federal Aviation 
Administration proposes to amend chapter I of Title 14, Code of Federal 
Regulations as follows:

PART 25--AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES

0
1. The authority citation for part 25 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, and 44704.
0
2. Amend Sec.  25.975 by revising paragraphs (a)(5) and (a)(6), and 
adding a new paragraph (a)(7) to read as follows:


Sec.  25.975  Fuel tank vents and carburetor vapor vents.

    (a) * * *
    (5) There may be no point in any vent line where moisture can 
accumulate with the airplane in the ground attitude or the level flight 
attitude, unless drainage is provided;
    (6) No vent or drainage provision may end at any point--
    (i) Where the discharge of fuel from the vent outlet would 
constitute a fire hazard; or
    (ii) From which fumes could enter personnel compartments; and
    (7) Each fuel tank system must be designed to prevent explosions 
caused by propagation of flames from outside the tank through the fuel 
tank vents into fuel tank vapor spaces for a minimum of 2 minutes and 
30 seconds of continuous exposure to flame impingement on any fuel tank 
vent.
* * * * *

PART 121--OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL 
OPERATIONS

0
3. The authority citation for part 121 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 40119, 41706, 44101, 44701-
44702, 44705, 44709-44711, 44713, 44716-44717, 44722, 46105.
0
4. Add Sec.  121.1119 to subpart AA to read as follows:


Sec.  121.1119  Fuel tank vent explosion protection.

    (a) Applicability. This section applies to transport category, 
turbine-powered airplanes with a type certificate issued after January 
1, 1958, that, as a result of original type certification or later 
increase in capacity, have:
    (1) A maximum type-certificated passenger capacity of 30 or more, 
or
    (2) A maximum payload capacity of 7,500 pounds or more.
    (b) New production airplanes. No certificate holder may operate an 
airplane for which the State of Manufacture issued the original 
certificate of airworthiness or export airworthiness approval after 
[insert date 2 years after effective date of rule] unless fuel tank 
vent system explosion prevention means meeting the requirements of 
Sec.  25.975 of this chapter, are installed and operational.

[[Page 48105]]

PART 129--OPERATIONS: FOREIGN AIR CARRIERS AND FOREIGN OPERATORS OF 
U.S.-REGISTERED AIRCRAFT ENGAGED IN COMMON CARRIAGE

0
5. The authority citation for part 129 continues to read as follows:

    Authority: 49 U.S.C. 40113, 40119, 41301, 44101, 44701-44702, 
44705, 44709-44711, 44713, 44716-44717, 44722, 44901-44904, 44906, 
44912, 46105, Public Law 107-71 sec. 104.
0
6. Add Sec.  129.119 to subpart B to read as follows:


Sec.  129.119  Fuel tank vent explosion protection.

    (a) Applicability. This section applies to transport category, 
turbine-powered airplanes with a type certificate issued after January 
1, 1958, that, as a result of original type certification or later 
increase in capacity, have:
    (1) A maximum type-certificated passenger capacity of 30 or more, 
or
    (2) A maximum payload capacity of 7,500 pounds or more.
    (b) New production airplanes. No certificate holder may operate an 
airplane for which the State of Manufacture issued the original 
certificate of airworthiness or export airworthiness approval after 
[insert date 2 years after effective date of rule] unless fuel tank 
vent system explosion prevention means meeting the requirements of 
Sec.  25.975 of this chapter, are installed and operational.

    Issued under authority provided by 49 U.S.C. 106(f), 44701(a), 
and 44703 in Washington, DC, on August 1, 2014.
Frank Paskiewicz,
Acting Director, Aircraft Certification Service.
[FR Doc. 2014-18959 Filed 8-14-14; 8:45 am]
BILLING CODE 4910-13-P


