
[Federal Register Volume 79, Number 152 (Thursday, August 7, 2014)]
[Rules and Regulations]
[Pages 46170-46171]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-18658]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2013-0903; Special Conditions No. 25-525-SC]


Special Conditions: Airbus Model A350-900 Series Airplane; Side-
Stick Controllers

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions.

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SUMMARY: These special conditions are issued for Airbus Model A350-900 
airplanes. These airplanes will have a novel or unusual design feature 
associated with side-stick controllers for pitch and roll control, 
instead of conventional wheels and columns. 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: Effective Date: September 8, 2014.

FOR FURTHER INFORMATION CONTACT: Loran Haworth, FAA, Airplane and 
Flight Interface Branch, ANM-111, Transport Airplane Directorate, 
Aircraft Certification Service, 1601 Lind Avenue SW., Renton, 
Washington 98057-3356; telephone (425) 227-1133; facsimile (425) 227-
1320.

SUPPLEMENTARY INFORMATION: 

Background

    On August 25, 2008, Airbus applied for a type certificate for their 
new Model A350-900 airplane. Later, Airbus requested, and the FAA 
approved, an extension to the application for FAA type certification to 
November 15, 2009. The Model A350-900 airplane has a conventional 
layout with twin wing-mounted Rolls-Royce Trent XWB 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 airplane configuration 
accommodates 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.
    The Airbus Model A350-900 airplane, like its predecessors the Model 
A320, A330, A340 and A380 airplanes, will use side-stick controllers 
for pitch and roll control. Regulatory requirements pertaining to 
conventional wheel and column controls, such as pilot strength and 
controllability, are not directly applicable for the side stick. In 
addition, pilot-control authority may be uncertain because the side 
sticks are not mechanically interconnected as with conventional wheel 
and column controls.

Type Certification Basis

    Under Title 14, Code of Federal Regulations (14 CFR) 21.17, Airbus 
must show that the Model A350-900 airplane meets the applicable 
provisions of 14 CFR part 25, as amended by Amendments 25-1 through 25-
129.
    The FAA has determined that Airbus Model A350-900 airplanes must 
comply with Sec. Sec.  25.143, 25.145(b), 25.175(b), 25.671, and 
25.1329(a).
    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 Airbus Model A350-900 airplane 
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 special conditions would also 
apply to the other model under Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the Airbus Model A350-900 airplane must comply with the 
fuel-vent

[[Page 46171]]

and exhaust-emission requirements of 14 CFR part 34, and the noise-
certification requirements of 14 CFR part 36. The FAA must issue a 
finding of regulatory adequacy under section 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 airplane will incorporate the following 
novel or unusual design features: side-stick controllers for pitch and 
roll control, in place of conventional wheel and column controls.

Discussion

    Current FAA regulations do not specifically address the use of 
side-stick controllers for pitch and roll control. The unique features 
of the side stick must therefore be demonstrated through flight and 
simulator tests to have suitable handling and control characteristics 
when considering the following:
    1. The handling-qualities tasks and requirements of the A350 
Special Conditions and other 14 CFR part 25 requirements for stability, 
control, and maneuverability, including the effects of turbulence.
    2. General ergonomics: Armrest comfort and support, local freedom 
of movement, displacement angle suitability, and axis harmony.
    3. Inadvertent input in turbulence.
    4. Inadvertent pitch-roll crosstalk.
    The Handling Qualities Rating Method (HQRM) of Appendix 5 of the 
Flight Test Guide, AC 25-7C, may be used to show compliance.
    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.

Discussion of Comments

    Notice of proposed special conditions no. 25-13-26-SC for Airbus 
Model A350-900 airplanes was published in the Federal Register on 
November 8, 2013 (78 FR 67077). No comments were received, and the 
special conditions are adopted as proposed.

Applicability

    As discussed above, these special conditions apply to Airbus Model 
A350-900 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 Airbus Model A350-900 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 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 airplanes.

Side-Stick Controllers

    1. Pilot strength: In lieu of the ``strength of pilots'' limits 
shown in Sec.  25.143(c) for pitch and roll, and in lieu of the 
specific pitch-force requirement of Sec. Sec.  25.145(b) and 25.175(d), 
it must be shown that the temporary and maximum prolonged force levels 
for the side-stick controllers are suitable for all expected operating 
conditions and configurations, whether normal or non-normal.
    2. Pilot-control authority: The electronic side-stick-controller 
coupling design must provide for corrective and/or overriding control 
inputs by either pilot with no unsafe characteristics. Annunciation of 
the controller status must be provided, and must not be confusing to 
the flightcrew.
    3. Pilot control: It must be shown by flight tests that the use of 
side-stick controllers does not produce unsuitable pilot-in-the-loop 
control characteristics when considering precision path control/tasks 
and turbulence. In addition, pitch and roll control force and 
displacement sensitivity must be compatible, so that normal inputs on 
one control axis will not cause significant unintentional inputs on the 
other.

    Issued in Renton, Washington, on July 15, 2014.
John P. Piccola, Jr.,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2014-18658 Filed 8-6-14; 8:45 am]
BILLING CODE 4910-13-P


