Federal Register / Vol. 79, No. 9 / Tuesday, January 14, 2014 / Proposed Rules 2387 

control laws presenting neutral 

longitudinal stability significantly 

below the normal operating speeds. 

‘‘Adequate awareness’’ means warning 

information must be provided to alert 

the crew of unsafe operating conditions 

and to enable them to take appropriate 

corrective action. 

c. The static directional stability (as 

shown by the tendency to recover from 

a skid with the rudder free) must be 

positive for any landing gear and flap 

position and symmetrical power 

condition, at speeds from 1.13 VSR1, up 

to VFE, VLE, or VFC/MFC (as appropriate). 

d. The static lateral stability (as 

shown by the tendency to raise the low 

wing in a sideslip with the aileron 

controls free) for any landing gear and 

wing-flap position and symmetric 

power condition, may not be negative at 

any airspeed (except that speeds higher 

than VFE need not be considered for 

wing-flaps extended configurations nor 

speeds higher than VLE for landing gear 

extended configurations) in the 

following airspeed ranges: 

(1) From 1.13 VSR1 to VMO /MMO. 

(2) From VMO/MMO to VFC/MFC, unless 

the divergence is— 

(i) Gradual; 

(ii) Easily recognizable by the pilot; 

and 

(iii) Easily controllable by the pilot. 

e. In straight, steady sideslips over the 

range of sideslip angles appropriate to 

the operation of the airplane, but not 

less than those obtained with one-half of 

the available rudder control movement 

(but not exceeding a rudder control 

force of 180 pounds), rudder control 

movements and forces must be 

substantially proportional to the angle 

of sideslip in a stable sense; and the 

factor of proportionality must lie 

between limits found necessary for safe 

operation. This requirement must be 

met for the configurations and speeds 

specified in paragraph (c) of this 

section. 

f. For sideslip angles greater than 

those prescribed by paragraph (e) of this 

section, up to the angle at which full 

rudder control is used or a rudder 

control force of 180 pounds is obtained, 

the rudder control forces may not 

reverse, and increased rudder deflection 

must be needed for increased angles of 

sideslip. Compliance with this 

requirement must be shown using 

straight, steady sideslips, unless full 

lateral control input is achieved before 

reaching either full rudder control input 

or a rudder control force of 180 pounds; 

a straight, steady sideslip need not be 

maintained after achieving full lateral 

control input. This requirement must be 

met at all approved landing gear and 

wing-flap positions for the range of 

operating speeds and power conditions 

appropriate to each landing gear and 

wing-flap position with all engines 

operating. 

Issued in Renton, Washington, on October 

22, 2013. 

Stephen P. Boyd, 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service. 

[FR Doc. 2014–00449 Filed 1–13–14; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. FAA–2013–0900; Notice No. 25– 

12–08–SC] 

Special Conditions: Airbus, Model 

A350–900 Series Airplane; General 

Limiting Requirements 

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. This airplane will 

have a novel or unusual design feature 

associated with general limiting 

requirements of its flight envelope 

protection features. 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 28, 2014. 

ADDRESSES: Send comments identified 

by docket number FAA–2013–0900 

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, 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 

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 ask that you send 

us two copies of written comments. 

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 


tkelley on DSK3SPTVN1PROD with PROPOSALS
2388 Federal Register / Vol. 79, No. 9 / Tuesday, January 14, 2014 / Proposed Rules 

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. 

Flight envelope protection is the 

subject of several proposed special 

conditions for the A350. Each specific 

type of envelope protection is addressed 

individually, but some requirements are 

common to all limiting systems and are 

therefore put forth as general limiting 

requirements. 

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 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 proposed 

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 Airbus Model A350–900 series 

will incorporate the following novel or 

unusual design features: General 

Limiting Requirements for the flight 

envelope protection system. 

Discussion 

This proposed special condition and 

the following ones which pertain to 

flight envelope protection present 

general limiting requirements for all the 

unique flight envelope protection 

features of the basic A350 Electronic 

Flight Control System (EFCS) design. 

Current regulations do not address these 

types of protection features. The general 

limiting requirements are necessary to 

ensure a smooth transition from normal 

flight to the protection mode and 

adequate maneuver capability. The 

general limiting requirements also 

ensure that the structural limits of the 

airplane are not exceeded. Furthermore, 

failure of the protection feature must not 

create hazardous flight conditions. 

Envelope protection parameters include 

angle of attack, normal load factor, bank 

angle, pitch angle, and speed. To 

accomplish these envelope protections, 

one or more significant changes occur in 

the EFCS control laws as the normal 

flight envelope limit is approached or 

exceeded. 

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 conditions as part of 

the type certification basis for Airbus 

Model A350–900 series airplanes. 

1. General Limiting Requirements. 

a. Onset characteristics of each 

envelope protection feature must be 

smooth, appropriate to the phase of 

flight and type of maneuver, and not in 

conflict with the ability of the pilot to 

satisfactorily change airplane flight 

path, speed, or attitude as needed. 

b. Limit values of protected flight 

parameters (and if applicable, associated 

warning thresholds) must be compatible 

with the following: 

(1) Airplane structural limits, 

(2) Required safe and controllable 

maneuvering of the airplane, and 

(3) Margins to critical conditions. 

Unsafe flight characteristics/conditions 

must not result if dynamic 

maneuvering, airframe and system 

tolerances (both manufacturing and inservice), and non-steady atmospheric 

conditions, in any appropriate 

combination and phase of flight, can 

produce a limited flight parameter 

beyond the nominal design limit value. 

c. The airplane must be responsive to 

intentional dynamic maneuvering to 

within a suitable range of the parameter 

limit. Dynamic characteristics such as 

damping and overshoot must also be 

appropriate for the flight maneuver and 

limit parameter in question. 

d. When simultaneous envelope 

limiting is engaged, adverse coupling or 

adverse priority must not result. 

2. Failure States 

EFCS failures (including sensor) must 

not result in a condition where a 

parameter is limited to such a reduced 

value that safe and controllable 

maneuvering is no longer available. The 

crew must be alerted by suitable means 

if any change in envelope limiting or 

maneuverability is produced by single 

or multiple failures of the EFCS not 

shown to be extremely improbable. 

Issued in Renton, Washington, on October 

22, 2013. 

Stephen P. Boyd, 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service. 

[FR Doc. 2014–00448 Filed 1–13–14; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. FAA–2013–0907; Notice No. 25– 

13–19–SC] 

Special Conditions: Airbus, Model 

A350–900 series airplane; Tire 

Failure—Debris Penetration or Rupture 

of Fuel Tank Structure 

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 airplane. These airplanes will 

have a novel or unusual design feature 


tkelley on DSK3SPTVN1PROD with PROPOSALS