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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46172 Federal Register / Vol. 79, No. 152 / Thursday, August 7, 2014 / Rules and Regulations 

unique in that traditional airplanes with 

conventional flight-control systems 

(mechanical linkages) are limited in the 

pitch axis only by the elevator surface 

area and deflection limit. The elevatorcontrol power is normally derived for 

adequate controllability and 

maneuverability at the most critical 

longitudinal pitching moment. The 

result is that traditional airplanes have 

a significant portion of the flight 

envelope wherein maneuverability in 

excess of limit structural-design values 

is possible. 

Title 14, Code of Federal Regulations 

(14 CFR) part 25 does not specify 

requirements or policy for 

demonstrating maneuver controls that 

impose any handling-qualities 

requirements beyond the design limit 

structural loads. Nevertheless, some 

pilots have become accustomed to the 

availability of this excess maneuver 

capacity in case of extreme emergency, 

such as upset recoveries or collision 

avoidance. 

These special conditions are needed 

to ensure adequate maneuverability and 

controllability for the Model A350–900 

airplane using the Airbus flight-control 

system. 

Type Certification Basis 

Under 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. 

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 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 final 

special conditions, the Model A350–900 

airplane must comply with the fuel-vent 

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: An electronic 

flight-control system (EFCS), that when 

operating in its normal mode, will 

prevent airplane pitch attitudes greater 

than +30 degrees and less than –15 

degrees, and roll angles greater than 

plus or minus 67 degrees. In addition, 

positive spiral stability is introduced for 

roll angles greater than 33 degrees at 

speeds below VMO/MMO. At speeds 

greater than VMO and up to VDF, 

maximum aileron-control force is 

limited to only 45 degrees maximum 

bank angle. 

Discussion 

Flight-envelope protection that limits 

normal load-factor (g) limiting is 

considered novel and unusual because 

the current regulations do not provide 

standards for maneuverability and 

controllability evaluations for such 

systems. Special conditions are needed 

to ensure adequate maneuverability and 

controllability when using this design 

feature. 

As with previous fly-by-wire 

airplanes, the FAA has no regulatory or 

safety reason to inhibit the design 

concept of the Airbus A350 flightcontrol system with load-factor limiting. 

Pilots accustomed to this control feature 

may feel more freedom in commanding 

full stick-displacement maneuvers 

because of the following: 

• Knowledge that the limit system 

will protect the structure, 

• Low stick-force/displacement 

gradients, and 

• Smooth transition from pilot 

elevator control to limit control. 

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. 25–13–28–SC for Airbus Model 

A350–900 airplanes was published in 

the Federal Register on December 17, 

2013 (78 FR 76249). 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 the 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, to meet the intent of 

adequate maneuverability and 

controllability required by § 25.143(a), 

and in the absence of other limiting 

factors, the following special conditions 

are issued as part of the typecertification basis for Airbus Model 

A350–900 airplanes. 

(1) The positive limiting load factor 

must not be less than: 

(a) 2.5g for the EFCS normal state 

with the high-lift devices retracted up to 

VMO/MMO. The positive limiting load 

factor may be gradually reduced down 

to 2.25g above VMO/MMO. 

(b) 2.0g for the EFCS normal state 

with the high-lift devices extended. 

(2) The negative limiting load factor 

must be equal to or more negative than: 

(a) Minus 1.0g for the EFCS normal 

state with the high-lift devices retracted. 

(b) 0.0g for the EFCS normal state 

with high-lift devices extended. 

(3) Maximum reachable positive loadfactor wings level may be limited by 

flight-control system characteristics or 

flight-envelope protections (other than 

load-factor protection) provided that: 

(a) The required values are readily 

achievable in turns, and 

(b) wings-level pitch-up 

responsiveness is satisfactory. 

(4) Maximum achievable negative 

load factor may be limited by flightcontrol system characteristics or flightenvelope protections (other than loadfactor protection) provided that: 

(a) Pitch-down responsiveness is 

satisfactory 

(b) from level flight, 0g is readily 

achievable or alternatively, a 

satisfactory trajectory change is readily 

achievable at operational speeds (from 

VLS to maximum speed—10 knots). VLS

is the lowest speed at which the crew 

may fly with auto-thrust or auto-pilot 

engaged. It is displayed on primary 

flight displays as the top of the lowVerDate Mar<15>2010 16:00 Aug 06, 2014 Jkt 232001 PO 00000 Frm 00006 Fmt 4700 Sfmt 4700 E:\FR\FM\07AUR1.SGM 07AUR1

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Federal Register / Vol. 79, No. 152 / Thursday, August 7, 2014 / Rules and Regulations 46173 

speed amber band, and is the lower end 

of the normal flight envelope. The 

formula (maximum speed—10 knots) is 

to cover typical margin from VMO/MMO

to cruise speeds, and typical margin 

from VFE to standard speed in high lift 

configurations. 

Note: For the FAA to consider a trajectory 

change as satisfactory, the applicant should 

propose and justify a pitch rate that provides 

sufficient maneuvering capability in the most 

critical scenarios. Compliance demonstration 

with the above requirements may be 

performed without ice accretion on the 

airframe. 

Issued in Renton, Washington, on July 15, 

2014. 

John P. Piccola, Jr., 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service. 

[FR Doc. 2014–18660 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–2014–0303; Special 

Conditions No. 25–561–SC] 

Special Conditions: Airbus Model 

A350–900 Airplane; Operation Without 

Normal Electrical Power 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final special condition; request 

for comments. 

SUMMARY: These special conditions are 

issued for the Airbus Model A350–900 

airplane. This airplane will have a novel 

or unusual design feature associated 

with operation without normal 

electrical power. 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 August 7, 2014. We 

must receive your comments by 

September 22, 2014. 

ADDRESSES: Send comments identified 

by docket number FAA–2014–0303 

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: 

Nazih Khaouly, FAA, Airframe and 

Flightcrew Interface Branch, ANM–111, 

Transport Airplane Directorate, Aircraft 

Certification Service, 1601 Lind Avenue 

SW., Renton, Washington 98057–3356; 

telephone (425) 227–2432; facsimile 

(425) 227–1320. 

SUPPLEMENTARY INFORMATION: The FAA 

has determined that notice of, and 

opportunity for prior public comment 

on, these special conditions is 

impracticable because these procedures 

would significantly delay issuance of 

the design approval and thus delivery of 

the affected aircraft. In addition, 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 publication in 

the Federal Register. 

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 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 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 Airbus Model 

A350–900 airplane 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. 

The Airbus Model A350–900 airplane 

fly-by-wire control system requires a 

continuous source of electrical power to 

maintain an operable flight-control 

system. The current rule, Title 14, Code 

of Federal Regulations (14 CFR) 

25.1351(d), Amendment 25–72, requires 

safe operation under visual flight rules 

(VFR) conditions for at least five 

minutes after loss of all normal 

electrical power. This rule was 

structured around a traditional design 

utilizing mechanical control cables for 

flight control while the crew took time 

to sort out the electrical failure, start 

engine(s) if necessary, and re-establish 

some of the electrical-power-generation 

capability. 

To maintain the same level of safety 

associated with traditional designs, 

Airbus Model A350–900 airplanes must 

be designed for operation with the 

normal sources of engine- or Auxiliary 

Power Unit (APU)-generated electrical 

power inoperative. Service experience 

has shown that loss of all electrical 

power from the airplane’s engine and 

APU-driven generators is not extremely 

improbable. Therefore, it must be shown 

that the airplane is capable of recovering 

adequate primary electrical-power 

generation for safe flight and landing 

with the use of its emergency electricalpower systems. These emergency 

electrical-power systems must be able to 


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