[Federal Register Volume 76, Number 30 (Monday, February 14, 2011)]
[Proposed Rules]
[Pages 8319-8321]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-3216]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM441 Special Conditions No. 25-11-01-SC]


Special Conditions: Gulfstream Model GVI Airplane; Design Roll 
Maneuver Requirement for Electronic Flight Controls

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed special conditions.

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SUMMARY: This action proposes special conditions for the Gulfstream GVI 
airplane. This airplane will have novel or unusual design features when 
compared to the state of technology envisioned in the airworthiness 
standards for transport category airplanes. These design features 
include an electronic flight control system that provides roll control 
of the airplane through pilot inputs to the flight

[[Page 8320]]

computers. 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: We must receive your comments by March 31, 2011.

ADDRESSES: You must mail two copies of your comments to: Federal 
Aviation Administration, Transport Airplane Directorate, Attn: Rules 
Docket (ANM-113), Docket No. NM441, 1601 Lind Avenue, SW., Renton, 
Washington 98057-3356. You may deliver two copies to the Transport 
Airplane Directorate at the above address. You must mark your comments: 
Docket No. NM441. You can inspect comments in the Rules Docket 
weekdays, except Federal holidays, between 7:30 a.m. and 4 p.m.

FOR FURTHER INFORMATION CONTACT: Carl Niedermeyer, FAA, Airframe/Cabin 
Safety Branch, ANM-115, Transport Standards Staff, Transport Airplane 
Directorate, Aircraft Certification Service, 1601 Lind Avenue, SW., 
Renton, Washington 98057-3356; telephone (425) 227-2279; 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 file in the docket all comments we receive, as well as a 
report summarizing each substantive public contact with FAA personnel 
concerning these special conditions. You can inspect the docket before 
and after the comment closing date. If you wish to review the docket in 
person, go to the address in the ADDRESSES section of this preamble 
between 7:30 a.m. and 4 p.m., Monday through Friday, except Federal 
holidays.
    We will consider all comments we receive on or before the closing 
date for comments. We will consider comments filed late if it is 
possible to do so without incurring expense or delay. We may change 
these special conditions based on the comments we receive.
    If you want us to acknowledge receipt of your comments on this 
proposal, include with your comments a self-addressed, stamped postcard 
on which you have written the docket number. We will stamp the date on 
the postcard and mail it back to you.

Background

    On March 29, 2005, Gulfstream Aerospace Corporation (hereafter 
referred to as ``Gulfstream'') applied for an FAA type certificate for 
its new Gulfstream Model GVI passenger airplane. Gulfstream later 
applied for, and was granted, an extension of time for the type 
certificate, which changed the effective application date to September 
28, 2006. The Gulfstream Model GVI airplane will be an all-new, two-
engine jet transport airplane with an executive cabin interior. The 
maximum takeoff weight will be 99,600 pounds, with a maximum passenger 
count of 19 passengers.

Type Certification Basis

    Under provisions of Title 14, Code of Federal Regulations (14 CFR) 
21.17, Gulfstream must show that the Gulfstream Model GVI airplane 
(hereafter referred to as ``the GVI'') meets the applicable provisions 
of 14 CFR part 25, as amended by Amendments 25-1 through 25-119, 25-
122, and 25-124. 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 GVI because of a novel 
or unusual design feature, special conditions are prescribed under the 
provisions of Sec.  21.16.
    In addition to complying with the applicable airworthiness 
regulations and special conditions, the GVI 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. The FAA must also issue a 
finding of regulatory adequacy pursuant to 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, in 
accordance with Sec.  11.38, and they become part of the type 
certification basis under Sec.  21.17(a)(2).
    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 novel or 
unusual design features, the special conditions would also apply to the 
other model under provisions of Sec.  21.101.

Novel or Unusual Design Features

    The GVI is equipped with an electronic flight control system that 
provides roll control of the airplane through pilot inputs to the 
flight computers. The current design roll maneuver requirement for 
structural loads in 14 CFR part 25 is inadequate for addressing an 
airplane with electronic flight controls that affect maneuvering. 
Special conditions are proposed to take into account the effects of an 
electronic flight control system.

Discussion of Proposed Special Conditions

    The GVI is equipped with an electronic flight control system that 
provides roll control of the airplane through pilot inputs to the 
flight computers. Current part 25 airworthiness regulations account for 
``control laws'' for which aileron deflection is proportional to 
control wheel deflection. They do not address any nonlinearities \1\ or 
other effects on aileron and spoiler actuation that may be caused by 
electronic flight controls. Therefore, the FAA considers the flight 
control system to be a novel and unusual feature compared to those 
envisioned when the current regulations were adopted. Since this type 
of system may affect flight loads, and therefore the structural 
capability of the airplane, special conditions are needed to address 
these effects.
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    \1\ A nonlinearity is a situation where output does not change 
in the same proportion as input.
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    These proposed special conditions differ from current requirements 
in that the special conditions require that the roll maneuver result 
from defined movements of the cockpit roll control as opposed to 
defined aileron deflections. Also, these proposed special conditions 
require an additional load condition at design maneuvering speed 
(VA), in which the cockpit roll control is returned to 
neutral following the initial roll input.

Applicability

    As discussed above, these proposed special conditions are 
applicable to the GVI. Should Gulfstream apply at a later date for a 
change to the type certificate to include another model incorporating 
the same novel or unusual design features, these proposed special 
conditions would apply to that model as well.

Conclusion

    This action affects only certain novel or unusual design features 
of the GVI. 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:


[[Page 8321]]


    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 the GVI airplanes.
    In lieu of compliance with Sec.  25.349(a), Gulfstream must comply 
with the following special conditions.
    The following conditions, speeds, and cockpit roll control motions 
(except as the motions may be limited by pilot effort) must be 
considered in combination with an airplane load factor of zero and of 
two-thirds of the positive maneuvering factor used in design. In 
determining the resulting control surface deflections, the torsional 
flexibility of the wing must be considered in accordance with Sec.  
25.301(b):
    1. Conditions corresponding to steady rolling velocities must be 
investigated. In addition, conditions corresponding to maximum angular 
acceleration must be investigated for airplanes with engines or other 
weight concentrations outboard of the fuselage. For the angular 
acceleration conditions, zero rolling velocity may be assumed in the 
absence of a rational time history investigation of the maneuver.
    2. At VA, sudden movement of the cockpit roll control up 
to the limit is assumed. The position of the cockpit roll control must 
be maintained until a steady roll rate is achieved and then must be 
returned suddenly to the neutral position.
    3. At VC, the cockpit roll control must be moved 
suddenly and maintained so as to achieve a roll rate not less than that 
obtained in paragraph 2.
    4. At VD, the cockpit roll control must be moved 
suddenly and maintained so as to achieve a roll rate not less than one 
third of that obtained in paragraph 2.

    Issued in Renton, Washington, on February 3, 2011.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-3216 Filed 2-11-11; 8:45 am]
BILLING CODE 4910-13-P