Document ID: FAA-2013-0890-0001
Agency: faa
Document Type: Proposed Rule
Title: Special Conditions: Airbus, Model A350-900 series airplane; Ground Pivoting Loads
Posted Date: 2013-10-29T04:00Z

[Federal Register Volume 78, Number 209 (Tuesday, October 29, 2013)]
[Proposed Rules]
[Pages 64415-64417]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-25398]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR part 25

[Docket No. FAA-2013-0890; Notice No. 25-13-10-SC]

Special Conditions: Airbus, Model A350-900 Series Airplane; 
Ground Pivoting Loads

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed special conditions.

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SUMMARY: This action proposes special conditions for Airbus Model A350-
900 series airplanes. These airplanes will have a novel or unusual 
design feature(s) associated with a braking system that affects the 
airplane's pivoting behavior. 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

[[Page 64416]]

that established by the existing airworthiness standards.

DATES: Send your comments on or before December 13, 2013.

ADDRESSES: Send comments identified by docket number FAA-2013-0890 
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: Todd Martin, FAA, Airframe/Cabin 
Safety, ANM-115, Transport Airplane Directorate, Aircraft Certification 
Service, 1601 Lind Avenue SW., Renton, Washington, 98057-3356; 
telephone (425) 227-1178; facsimile (425) 227-1320.

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 proposed special conditions, 
explain the reason for any recommended change, and include supporting 
data. We ask that you send us two copies of written comments.
    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 August 25, 2008, Airbus applied for a type certificate for their 
new Model A350-900 series airplane. Later, Airbus requested and the FAA 
approved an extension to the application for FAA type certification to 
June 28, 2009. The Model A350-900 series airplane has a conventional 
layout with twin wing-mounted Rolls-Royce Trent engines. It features a 
twin aisle 9-abreast economy class layout, and accommodates side-by-
side placement of LD-3 containers in the cargo compartment. The basic 
Model A350-900 series configuration will accommodate 315 passengers in 
a standard two-class arrangement. The design cruise speed is Mach 0.85 
with a Maximum Take-Off Weight of 602,000 lbs. Airbus proposes the 
Model A350-900 series airplane to be certified for extended operations 
(ETOPS) beyond 180 minutes at entry into service for up to a 420-minute 
maximum diversion time.
    The Airbus Model A350-900 series airplane is equipped with a 
braking system that affects the airplane's pivoting behavior. During 
pivoting the braking system inhibits braking on some wheels. Title 14 
Code of Federal Regulations (14 CFR) 25.503 and European Aviation 
Safety Agency (EASA) Certification Specification (CS) section 25.503, 
each specify limit loads due to pivoting, however, system effects are 
not taken into account.

Type Certification Basis

    Under Title 14, Code of Federal Regulations (14 CFR) 21.17, Airbus 
must show that the Model A350-900 series meets the applicable 
provisions of 14 CFR part 25, as amended by Amendments 25-1 through 25-
128.
    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 Model A350-900 series because of a 
novel or unusual design feature, special conditions are prescribed 
under 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 proposed special conditions would 
also apply to the other model under Sec.  21.101.
    In addition to the applicable airworthiness regulations and 
proposed special conditions, the Model A350-900 series 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, 
under Sec.  11.38, and they become part of the type-certification basis 
under Sec.  21.17(a)(2).

Novel or Unusual Design Features

    The Airbus Model A350-900 series airplane will incorporate the 
following novel or unusual design features: a braking system that 
affects the airplane's pivoting behavior.

Discussion

    Within the Aviation Rulemaking Advisory Committee, the Loads and 
Dynamics Harmonization Working Group developed criteria for determining 
pivoting loads. The group recommended, for airplanes with more than two 
main landing gear units, a rational pivoting maneuver that takes into 
account the effects of the braking system and tire characteristics, in 
lieu of the current requirement. Although the Airbus Model A350-900 
series airplane has two main landing gear units, EASA and the FAA 
propose to apply the same criteria on this airplane.

Applicability

    As discussed above, these proposed special conditions apply to 
Airbus Model A350-900 series airplanes. Should Airbus apply later for a 
change to the type certificate to include another model incorporating 
the same novel or unusual design feature, the proposed special 
conditions would apply to that model as well.

Conclusion

    This action affects only certain novel or unusual design features 
on the Airbus Model A350-900 series 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.

[[Page 64417]]

The Proposed Special Conditions

    Accordingly, the Federal Aviation Administration (FAA) proposes the 
following special conditions as part of the type certification basis 
for Airbus Model A350-900 series airplanes in lieu of Sec.  25.503:
    1. The main landing gear and supporting structure must be designed 
for the loads induced by pivoting during ground maneuvers.
    (a) The following rational pivoting maneuvers must be considered:
    (i) Towing at the nose gear at the critical towing angle with no 
brakes applied, including cases with torque links disconnected; and 
separately,
    (ii) Application of symmetrical or unsymmetrical forward thrust to 
aid pivoting, with or without braking by pilot action on the pedals.
    (b) The airplane is assumed to be in static equilibrium, with the 
loads being applied at the ground contact points.
    (c) The limit vertical load factor must be 1.0, and:
    (i) For wheels with brakes applied, the coefficient of friction 
must be 0.8,
    (ii) For wheels with brakes not applied, the ground tire reactions 
must be based on reliable tire data.

    Issued in Renton, Washington, on September 12, 2013.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-25398 Filed 10-28-13; 8:45 am]
BILLING CODE 4910-13-P