46170 Federal Register / Vol. 79, No. 152 / Thursday, August 7, 2014 / Rules and Regulations 

Applicability 

As discussed above, these special 

conditions apply to the 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 the 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. 

In lieu of § 25.361(b), the following 

special conditions apply: 

1. For turbine-engine installations, the 

engine mounts, pylons, and adjacent 

supporting airframe structure must be 

designed to withstand 1g level flight 

loads acting simultaneously with the 

maximum limit torque loads imposed 

by each of the following: 

a. Sudden engine deceleration due to 

a malfunction that could result in a 

temporary loss of power or thrust, and 

b. the maximum acceleration of the 

engine. 

2. For auxiliary power-unit 

installations, the power-unit mounts 

and adjacent supporting airframe 

structure must be designed to withstand 

1g level flight loads acting 

simultaneously with the maximum limit 

torque loads imposed by each of the 

following: 

a. Sudden auxiliary power-unit 

deceleration due to malfunction or 

structural failure, and 

b. the maximum acceleration of the 

power unit. 

3. For engine-supporting structure, an 

ultimate loading condition must be 

considered that combines 1g flight loads 

with the transient dynamic loads 

resulting from: 

a. The loss of any fan, compressor, or 

turbine blade, and separately 

b. where applicable to a specific 

engine design, any other engine 

structural failure that results in higher 

loads. 

4. The ultimate loads developed from 

the conditions specified in special 

conditions 3.a. and 3.b. are to be 

multiplied by a factor of 1.0 when 

applied to engine mounts and pylons, 

and multiplied by a factor of 1.25 when 

applied to adjacent supporting airframe 

structure. 

5. The airplane must be capable of 

continued safe flight considering the 

aerodynamic effects on controllability 

due to any permanent deformation that 

results from the conditions specified in 

special condition 3. 

Issued in Renton, Washington, on July 15, 

2014. 

John P. Piccola, Jr., 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service. 

[FR Doc. 2014–18657 Filed 8–6–14; 8:45 am] 

BILLING CODE 4910–13–P 

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. 

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 wingmounted 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 §§ 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 § 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 § 21.101. 

In addition to the applicable 

airworthiness regulations and special 

conditions, the Airbus Model A350–900 

airplane must comply with the fuel-vent 


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Federal Register / Vol. 79, No. 152 / Thursday, August 7, 2014 / Rules and Regulations 46171 

and exhaust-emission requirements of 

14 CFR part 34, and the noisecertification 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 § 11.38, 

and they become part of the typecertification basis under § 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 typecertification basis for Airbus Model 

A350–900 airplanes. 

Side-Stick Controllers 

1. Pilot strength: In lieu of the 

‘‘strength of pilots’’ limits shown in 

§ 25.143(c) for pitch and roll, and in lieu 

of the specific pitch-force requirement 

of §§ 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 nonnormal. 

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 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. FAA–2013–0905; Special 

Conditions No. 25–531–SC] 

Special Conditions: Airbus Model 

A350–900 Airplane; Flight-Envelope 

Protection, Normal Load-Factor (G) 

Limiting 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final special conditions. 

SUMMARY: These special conditions are 

issued for Airbus Model A350–900 

airplanes. These airplanes will have a 

novel or unusual design feature 

associated with a flight-control system 

that prevents the pilot from 

inadvertently or intentionally exceeding 

the positive or negative airplane limit 

load factor. 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: Joe 

Jacobsen, FAA, Airplane and Flightcrew 

Interface Branch, ANM–111, Transport 

Airplane Directorate, Aircraft 

Certification Service, 1601 Lind Avenue 

SW., Renton, Washington 98057–3356; 

telephone (425) 227–2011; 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 wingmounted 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 normal load-factor limit on 

Airbus Model A350–900 airplanes is 


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