Special Conditions: Airbus, A350-900 Series Airplane; Design Roll Maneuver, 2365-2366 [2014-00451]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 79, Number 9 (Tuesday, January 14, 2014)]
[Rules and Regulations]
[Pages 2365-2366]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-00451]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2013-0895; Notice No. 25-516-SC]


Special Conditions: Airbus, A350-900 Series Airplane; Design Roll 
Maneuver

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions, request for comments.

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SUMMARY: These special conditions are issued for Airbus Model A350-900 
series airplanes. These airplanes will have a novel or unusual design 
feature(s) associated with the airplane's response to the design roll 
maneuver. The applicable airworthiness regulations do not contain 
adequate or appropriate safety standards for this design feature. These 
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: The effective date of these special conditions is January 14, 
2014. We must receive your comments by February 28, 2014.

ADDRESSES: Send comments identified by docket number FAA-2013-0895 
using any of the following methods:
     Federal eRegulations Portal: Go to https://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 https://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 https://DocketsInfo.dot.gov/.
    Docket: Background documents or comments received may be read at 
https://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 and Cabin 
Safety Branch, 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: The substance of these special conditions 
has been subject to the public comment process in several prior 
instances with no substantive comments received. The FAA therefore 
finds that good cause exists for making these special conditions 
effective upon issuance.

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 by 45 days after 
publication of these special condition in the Federal Register. 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 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 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 is equipped with an electronic 
flight control system that provides control of the aircraft through 
pilot inputs to the flight computer. Current part 25 airworthiness 
regulations account for control laws for which aileron deflection is 
proportional to control stick deflection. They do not address any 
nonlinearities or other effects on aileron actuation that may be caused 
by electronic flight controls. Since this type of system may affect 
flight loads, and therefore the structural capability of the airplane, 
specific regulations are needed to address these effects. These special 
conditions adjust the current roll maneuver requirement, Title 14, Code 
of Federal Regulations (14 CFR) 25.349(a), to take into account the 
effects of an electronic flight control system.

Type Certification Basis

    Under Sec.  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 25-129.
    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 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 novel or 
unusual design feature, the special conditions would also apply to the 
other model.
    In addition to the applicable airworthiness regulations and 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 section 611 of Public Law 92-574, 
the ``Noise Control Act of 1972.''

[[Page 2366]]

    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 will incorporate the following 
novel or unusual design features: An electronic flight control system 
that can affect how the airplane responds to a roll maneuver. This 
requires that the roll maneuver result from defined movements of the 
cockpit roll control as opposed to defined aileron deflections. This 
also requires an additional load condition at VA, in which 
the cockpit roll control is returned to neutral following the initial 
roll input.

Discussion

    These proposed special conditions differ from similar special 
conditions applied on previous programs; and are limited to the roll 
axis only, whereas previous special conditions also included the pitch 
and yaw axes. Special conditions are no longer needed for the pitch or 
yaw axes, because 14 CFR part 25 Amendment 25-91 takes into account the 
effects of an electronic flight control system in those axes (Sec.  
25.331 for pitch and Sec.  25.351 for yaw).

Applicability

    As discussed above, these 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 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.
    The substance of these special conditions has been subjected to the 
notice and comment period in several prior instances and has been 
derived without substantive change from those previously issued. It is 
unlikely that prior public comment would result in a significant change 
from the substance contained herein. Therefore, the FAA has determined 
that prior public notice and comment are unnecessary and impracticable, 
and good cause exists for adopting these special conditions upon 
issuance. The FAA is requesting comments to allow interested persons to 
submit views that may not have been submitted in response to the prior 
opportunities for comment described above.

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 Special Conditions

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the following special conditions are issued as part of 
the type certification basis for Airbus Model A350-900 series 
airplanes.

1. Design Roll Maneuver Conditions

    The following conditions, speeds, and cockpit roll control motions 
(except as the motions may be limited by pilot effort) must be 
considered in combination with an airplane load factor of zero and of 
two-thirds of the positive maneuvering factor used in design. In 
determining the resulting control surface deflections, the torsional 
flexibility of the wing must be considered in accordance with Sec.  
25.301(b):
    a. Conditions corresponding to steady rolling velocities must be 
investigated. In addition, conditions corresponding to maximum angular 
acceleration must be investigated for airplanes with engines or other 
weight concentrations outboard of the fuselage. For the angular 
acceleration conditions, zero rolling velocity may be assumed in the 
absence of a rational time history investigation of the maneuver.
    b. At VA, sudden movement of the cockpit roll control up 
to the limit is assumed. The position of the cockpit roll control must 
be maintained until a steady roll rate is achieved and then must be 
returned suddenly to the neutral position.
    c. At VC, the cockpit roll control must be moved 
suddenly and maintained so as to achieve a roll rate not less than that 
obtained in paragraph b.
    d. At VD, the cockpit roll control must be moved 
suddenly and maintained so as to achieve a roll rate not less than one-
third of that obtained in paragraph b.

    Issued in Renton, Washington, on October 22, 2013.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2014-00451 Filed 1-13-14; 8:45 am]
BILLING CODE 4910-13-P