1336 Federal Register / Vol. 79, No. 5 / Wednesday, January 8, 2014 / Proposed Rules 

2Cherry, R. and Warren, K. ‘‘Fuselage 

Burnthrough Protection for Increased Postcrash 

Occupant Survivability: Safety Benefit Analysis 

Based on Past Accidents, ‘‘FAA Report DOT/FAA/ 

AR–99/57, September 1999 and R G W Cherry & 

Associates Limited, ‘‘A Benefit Analysis for Cabin 

Water Spray Systems and Enhanced Fuselage 

Burnthrough Protection,’’ FAA Report DOT/FAA/

AR–02/49, April 7, 2003. 

are the structural integrity of the wing 

and tank, flammability of the tank, burnthrough resistance of the wing skin, and 

the presence of auto-ignition threats 

during exposure to a fire. The FAA 

assessed post-crash survival time during 

the adoption of Amendment 25–111 for 

fuselage burn-through protection. 

Studies conducted by and on behalf of 

the FAA indicated that, following a 

survivable accident, prevention of 

fuselage burn-through for approximately 

5 minutes can significantly enhance 

survivability.2

There is little benefit in requiring the 

design to prevent wing skin burnthrough beyond five minutes, due to the 

effects of the fuel fire itself on the rest 

of the airplane. That assessment was 

carried out based on accidents involving 

airplanes with conventional fuel tanks, 

and considering the ability of ground 

personnel to rescue occupants. In 

addition, AC 20–135 indicates that, 

when aluminum is used for fuel tanks, 

the tank should withstand the effects of 

fire for 5 minutes without failure. 

Therefore, to be consistent with existing 

capability and related requirements, the 

Model A350–900 series airplane fuel 

tanks must be capable of resisting a 

post-crash fire for at least 5 minutes. In 

demonstrating compliance, Airbus must 

address a range of fuel loads from 

minimum to maximum, as well as any 

other critical fuel load. 

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 under the provisions of 

§ 21.101. 

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. 

The Proposed Special Conditions 

Accordingly, pursuant to the 

authority delegated to me by the 

Administrator, the following special 

conditions are proposed as part of the 

type certification basis for the Model 

A350–900 series airplane: 

In addition to complying with 14 CFR 

part 25 regulations governing the firesafety performance of the fuel tanks, 

wings, and nacelle, the Airbus Model 

A350–900 series airplane must 

demonstrate acceptable post-crash 

survivability in the event the wings are 

exposed to a large fuel-fed ground fire. 

Airbus must demonstrate that the wing 

and fuel tank design can endure an 

external fuel-fed pool fire for at least 

five minutes. This shall be 

demonstrated for minimum fuel loads 

(not less than reserve fuel levels) and 

maximum fuel loads (maximum range 

fuel quantities), and other identified 

critical fuel loads. Considerations shall 

include fuel tank flammability, burnthrough resistance, wing structural 

strength retention properties, and autoignition threats during a ground fire 

event for the required time duration. 

Issued in Renton, Washington, on October 

22, 2013. 

Stephen P. Boyd 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service. 

[FR Doc. 2014–00102 Filed 1–7–14; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. FAA–2013–0901; Notice 

No. 25–13–23–SC] 

Special Conditions: Airbus, Model 

A350–900 Series Airplane; Flight 

Envelope Protection: High Speed 

Limiting 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed special 

conditions. 

SUMMARY: This action proposes special 

conditions for Airbus Model A350–900 

series airplanes. These airplanes will 

have a novel or unusual design feature 

associated with high speed limiting. 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 that established by the 

existing airworthiness standards. 

DATES: Send your comments on or 

before February 7, 2014. 

ADDRESSES: Send comments identified 

by docket number FAA–2013–0901 

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: 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: 

Comments Invited 

We invite interested people to take 

part in this rulemaking by sending 

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Federal Register / Vol. 79, No. 5 / Wednesday, January 8, 2014 / Proposed Rules 1337 

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 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 has a 

conventional layout with twin wingmounted Rolls-Royce Trent engines. It 

features a twin aisle 9-abreast economy 

class layout, and accommodates side-byside 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 longitudinal control law design of 

the Airbus Model A350–900 

incorporates an overspeed protection 

system in the normal mode; this would 

prevent the pilot from inadvertently or 

intentionally exceeding a speed 

approximately equivalent to VFC or 

attaining VDF. Current Title 14 Code of 

Federal Regulations (14 CFR) part 25 

sections do not relate to a high speed 

limiting protection system that might 

preclude or modify flying qualities 

assessments in the overspeed region. 

However, the requirements of § 25.253 

(High-speed characteristics) and its 

related policy are applicable to the 

Model A350–900 series and not affected 

by this proposed special condition. 

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 25–129. 

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 Airbus Model A350–900 series 

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 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 

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 Model A350–900 series will 

incorporate the following novel or 

unusual design features: An overspeed 

protection system which prevents the 

pilot from inadvertently or intentionally 

exceeding a speed approximately 

equivalent to VFC or attaining VDF. 

At VMO + 10 knots or MMO + 0.02, an 

automatic nose up pitch is applied with 

phase advance in case of high 

acceleration. The speed stabilizes at VD

¥ 10kts/MD ¥ 0.02 if the stick is full 

forward, or the speed will return below 

VMO/MMO if the stick is released. 

Discussion 

This proposed special condition 

establishes requirements to ensure that 

operation of the high speed limiting 

protection system does not impede 

normal attainment of speeds up to the 

overspeed warning. Its main features 

are: 

1. It protects the airplane against high 

speed/high Mach number flight 

conditions beyond VMO/MMO. 

2. It does not interfere with flight at 

VMO/MMO, even in turbulent air. 

3. It still provides load factor 

limitation through the ‘‘pitch limiting’’ 

function described below. 

4. It restores positive static stability 

beyond VMO/MMO. 

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. 

The Proposed Special Conditions 

Accordingly, the Federal Aviation 

Administration (FAA) proposes the 

following special condition as part of 

the type certification basis for Airbus 

Model A350–900 series airplanes. 

In addition to § 25.143, the following 

requirements apply: Operation of the 

high speed limiter during all routine 

and descent procedure flight must not 

impede normal attainment of speeds up 

to overspeed warning 

Issued in Renton, Washington, on October 

22, 2013. 

Stephen P. Boyd, 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service. 

[FR Doc. 2014–00100 Filed 1–7–14; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. FAA–2013–0892; Notice 

No. 25–13–21–SC] 

Special Conditions: Airbus, A350–900 

Series Airplane; Crashworthiness— 

Emergency Landing Conditions 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed special 

conditions. 

SUMMARY: This action proposes special 

conditions for the Airbus Model A350– 

900 series airplanes. These airplanes 

will have a novel or unusual design 

feature associated with crashworthiness 

of carbon fiber reinforced plastic used in 

the construction of the fuselage. 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 

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