Document ID: FAA-2013-0901-0001
Agency: faa
Document Type: Proposed Rule
Title: Special Conditions: Airbus, Model A350-900 Series Airplane; Flight Envelope Protection: High Speed Limiting
Posted Date: 2014-01-08T05:00Z

[Federal Register Volume 79, Number 5 (Wednesday, January 8, 2014)]
[Proposed Rules]
[Pages 1336-1337]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-00100]

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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.

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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

[[Page 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 wing-mounted Rolls-Royce Trent 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 
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 Sec.  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 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 
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 Sec.  11.38, and they become part of the type-certification basis 
under Sec.  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 Sec.  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