
[Federal Register Volume 78, Number 218 (Tuesday, November 12, 2013)]
[Proposed Rules]
[Pages 67321-67323]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-26936]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No.FAA-2013-0942; Notice No. 25-13-30-SC]


Special Conditions: Bombardier Aerospace Inc., Models BD-500-1A10 
and BD-500-1A11 Series Airplanes; Autobraking System Loads

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed special conditions.

-----------------------------------------------------------------------

SUMMARY: This action proposes special conditions for the Bombardier 
Aerospace Inc. Models BD-500-1A10 and BD-500-1A11 series airplanes. 
These airplanes will have novel or unusual design features associated 
with the autobraking system for use during landing. The applicable 
airworthiness regulations do not contain adequate or appropriate safety 
standards for this design feature. These proposed special conditions 
contain the additional safety standards that the Administrator 
considers necessary to establish a level of safety equivalent to that 
established by the existing airworthiness standards.

DATES: Send your comments on or before December 27, 2013.

ADDRESSES: Send comments identified by docket number FAA-2013-0942 
using any of the following methods:
     Federal eRegulations 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: Mark Freisthler, FAA, Airframe and 
Cabin Safety Branch, ANM-115 Transport Airplane Directorate, Aircraft

[[Page 67322]]

Certification Service, 1601 Lind Avenue SW., Renton, Washington, 98057-
3356; telephone 425-227-1119; facsimile 425-227-1232.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite interested people to take part in this rulemaking by 
sending written comments, data, or views. The most helpful comments 
reference a specific portion of the special conditions, explain the 
reason for any recommended change, and include supporting data.
    We will consider all comments we receive on or before the closing 
date for comments. We may change these special conditions based on the 
comments we receive.

Background

    On December 10, 2009, Bombardier Inc. applied for a type 
certificate for their new Models BD-500-1A10 and BD-500-1A11 series 
airplanes (hereafter collectively referred to as ``C-series''). The C-
series airplanes are swept-wing monoplanes with a pressurized cabin. 
They share an identical supplier base and significant common design 
elements. The fuselage is an aluminum alloy material, blended double-
bubble design, sized for nominal 5-abreast seating. Each airplane's 
powerplant consists of two under wing Pratt and Whitney PW1524G ultra-
high bypass, geared turbofan engines. Flight controls are fly-by-wire 
systems with two passive/uncoupled side sticks. Avionics include five 
landscape primary cockpit displays. The dimensions of the airplanes 
encompass a wingspan of 115 feet; a height of 37.75 feet; and a length 
of 114.75 feet for the Model BD-500-1A10 and 127 feet for the Model BD-
500-1A11. Passenger capacity is designated as 110 for the Model BD-500-
1A10 and 125 for the Model BD-500-1A11. Maximum takeoff weight is 
131,000 pounds for the Model BD-500-1A10 and 144,000 pounds for the 
Model BD-500-1A11. Maximum takeoff thrust is 21,000 pounds for the 
Model BD-500-1A10 and 23,300 pounds for the Model BD-500-1A11. Range is 
3,394 miles (5,463 kilometres) for both models of airplanes. Maximum 
operating altitude is 41,000 feet for both models of airplanes.

Type Certification Basis

    Under the provisions of Title 14, Code of Federal Regulations (14 
CFR) 21.17, Bombardier Inc. must show that the C-series airplanes meet 
the applicable provisions of part 25 as amended by Amendments 25-1 
through 25-129.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 25) do not contain adequate or 
appropriate safety standards for the C-series airplanes because of a 
novel or unusual design feature, special conditions are prescribed 
under the provisions of Sec.  21.16.
    Special conditions are initially applicable to the model for which 
they are issued. Should the type certificate for that model be amended 
later to include any other model that incorporates the same or similar 
novel or unusual design feature, the special conditions would also 
apply to the other model under Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the C-series airplanes must comply with the fuel vent and 
exhaust emission requirements of 14 CFR part 34 and the noise 
certification requirements of 14 CFR part 36, and the FAA must issue a 
finding of regulatory adequacy under Sec.  611 of Public Law 92-574, 
the ``Noise Control Act of 1972.''
    The FAA issues special conditions, as defined in 14 CFR 11.19, in 
accordance with Sec.  11.38, and they become part of the type 
certification basis under Sec.  21.17(a)(2).

Novel or Unusual Design Features

    The C-series airplanes will incorporate the following novel or 
unusual design features: The C-series airplanes possess an autobrake 
system. This is a pilot-selectable function that allows earlier maximum 
braking at landing without pilot pedal input. When the autobrake system 
is armed before landing, it automatically commands maximum braking at 
main wheels touchdown. Normal procedures remain unchanged and call for 
manual braking after nose wheel touchdown.

Discussion

    Section 25.493 addresses braked roll loads but does not contain a 
specific ``pitchover'' requirement addressing the loading on the nose 
gear, the nose gear surrounding structure, and the forward fuselage. 
Moreover, Sec.  25.493 specifies airplane attitudes in accordance with 
figure 6 of appendix A to part 25, which are level landing attitudes. 
For airplanes with traditional braking systems, the current ground load 
requirements are considered adequate for the design of the nose gear 
and airframe structure. However, the C-Series airplane autobrake 
system, which could apply maximum braking at the main wheels with the 
airplane in a tail-down attitude well before the nose touches down, 
will cause a high nose gear sink rate and potentially higher gear and 
airframe loads.
    Part 25 does not contain adequate requirements to address the 
potentially higher structural loads that could result from this type of 
braking system. In addition, the effects on fatigue covered by Sec.  
25.571 also need to be considered. Therefore, FAA has determined that 
additional airworthiness standards are needed for the certification of 
this unusual design feature. These special conditions propose 
airworthiness standards for the certification of the C-series airplanes 
with an autobrake system.

Applicability

    As discussed above, these special conditions are applicable to the 
Models BD-500-1A10 and BD-500-1A11 series airplanes. Should Bombardier 
Inc. apply at a later date for a change to the type certificate to 
include another model incorporating the same novel or unusual design 
feature, the special conditions would apply to that model as well.

Conclusion

    This action affects only certain novel or unusual design features 
on one series of airplanes. It is not a rule of general applicability.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.
    The authority citation for these special conditions is as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701, 44702, 44704.

The Proposed Special Conditions

    Accordingly, the Federal Aviation Administration (FAA) proposes the 
following special conditions as part of the type certification basis 
for Bombardier Inc. Models BD-500-1A10 and BD-500-1A11 series 
airplanes.

Autobraking System Loads

    A landing pitchover condition must be addressed that takes into 
account the effect of the autobrake system. The airplane is assumed to 
be at the design maximum landing weight, or at the maximum weight 
allowed with the autobrake system on. The airplane is assumed to land 
in a tail-down attitude at the speeds defined by Sec.  25.481. 
Following main gear contact, the airplane is assumed to rotate about 
the main gear wheels at the highest pitch rate generated by the 
autobrake system. This is considered a limit load condition from which 
ultimate loads must also be determined. Loads must be determined for a 
critical fuel and payload distribution and centers of

[[Page 67323]]

gravity. Nose gear loads, as well as airframe loads, must be 
determined. The airplane must support these loads as described in Sec.  
25.305.
    In addition to the above airworthiness standards, fatigue loads 
must also be determined and applied in accordance to Sec.  25.571.

    Issued in Renton, Washington, on November 1, 2013.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-26936 Filed 11-8-13; 8:45 am]
BILLING CODE 4910-13-P


