[Federal Register Volume 76, Number 32 (Wednesday, February 16, 2011)]
[Proposed Rules]
[Pages 8917-8919]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-3412]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM445 Special Conditions No. 25-11-04-SC]
Special Conditions: Gulfstream Model GVI Airplane; Automatic
Speed Protection for Design Dive Speed
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 a high speed protection system. 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 April 4, 2011.
[[Page 8918]]
ADDRESSES: You must mail two copies of your comments to: Federal
Aviation Administration, Transport Airplane Directorate, Attn: Rules
Docket (ANM-113), Docket No. NM445, 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. NM445. 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 a high speed protection system that limits
nose down pilot authority at speeds above VC/MC,
and prevents the airplane from actually performing the maneuver
required under Sec. 25.335(b)(1). The applicable airworthiness
regulations do not contain adequate or appropriate safety standards for
this design feature. These proposed special conditions address this
design feature. These proposed special conditions are identical or
nearly identical to those previously required for type certification of
other airplane models.
Discussion of Proposed Special Conditions
Gulfstream proposes to reduce the speed margin between
VC and VD required by Sec. 25.335(b), based on
the incorporation of a high speed protection system in the GVI flight
control laws. The GVI is equipped with a high speed protection system
that limits nose down pilot authority at speeds above VC/
MC and prevents the airplane from actually performing the
maneuver required under Sec. 25.335(b)(1).
Section 25.335(b)(1) is an analytical envelope condition which was
originally adopted in Part 4b of the civil air regulations to provide
an acceptable speed margin between design cruise speed and design dive
speed. Freedom from flutter and the airframe design loads are affected
by the design dive speed. While the initial condition for the upset
specified in the rule is 1g level flight, protection is afforded for
other inadvertent overspeed conditions as well. Section 25.335(b)(1) is
intended as a conservative enveloping condition for all potential
overspeed conditions, including non-symmetric ones.
To establish that all potential overspeed conditions are enveloped,
the applicant would demonstrate that the dive speed will not be
exceeded during pilot-induced or gust-induced upsets in non-symmetric
attitudes.
In addition, the high speed protection system in the GVI must have
a high level of reliability.
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:
Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.
The Proposed Special Conditions
Accordingly, the Federal Aviation Administration (FAA) proposes the
[[Page 8919]]
following special conditions as part of the type certification basis
for the GVI airplanes.
1. In lieu of compliance with Sec. 25.335(b)(1), if the flight
control system includes functions that act automatically to initiate
recovery before the end of the 20 second period specified in Sec.
25.335(b)(1), VD/MD must be determined from the
greater of the speeds resulting from conditions (a) and (b) below. The
speed increase occurring in these maneuvers may be calculated if
reliable or conservative aerodynamic data are used.
(a) From an initial condition of stabilized flight at
VC/MC, the airplane is upset so as to take up a
new flight path 7.5 degrees below the initial path. Control
application, up to full authority, is made to try to maintain this new
flight path. Twenty seconds after initiating the upset, manual recovery
is made at a load factor of 1.5 g (0.5 acceleration increment), or a
greater load factor that is automatically applied by the system with
the pilot's pitch control neutral. Power, as specified in Sec.
25.175(b)(1)(iv), is assumed until recovery is initiated, at which time
power reduction and the use of pilot controlled drag devices may be
used.
(b) From a speed below VC/MC, with power to
maintain stabilized level flight at this speed, the airplane is upset
so as to accelerate through VC/MC at a flight
path 15 degrees below the initial path (or at the steepest nose down
attitude that the system will permit with full control authority if
less than 15 degrees). The pilot's controls may be in the neutral
position after reaching VC/MC and before recovery
is initiated. Recovery may be initiated three seconds after operation
of high speed warning system by application of a load factor of 1.5g
(0.5 acceleration increment), or such greater load factor that is
automatically applied by the system with the pilot's pitch control
neutral. Power may be reduced simultaneously. All other means of
decelerating the airplane, the use of which are authorized up to the
highest speed reached in the maneuver, may be used. The interval
between successive pilot actions must not be less than one second.
2. The applicant must also demonstrate that the speed margin,
established as above, will not be exceeded in inadvertent or gust
induced upsets resulting in initiation of the dive from non-symmetric
attitudes, unless the airplane is protected by the flight control laws
from getting into non-symmetric upset conditions. The upset maneuvers
described in Advisory Circular 25-7A, Change 1, section 32, paragraphs
c.(3)(i) and (iii) may be used to comply with this requirement.
3. Any failure of the high speed protection system that would
affect the speed margin determined by paragraphs 1. and 2. must be
improbable (occur at a rate less than 10-5 per flight hour).
4. Failures of the system must be annunciated to the pilots, and
flight manual instructions must be provided to reduce the maximum
operating speeds, VMO/MMO. The operating speed
must be reduced to a value that maintains a speed margin between
VMO/MMO and VD/MD that is
consistent with showing compliance with Sec. 25.335(b) without the
benefit of the high speed protection system.
5. Master minimum equipment list (MMEL) relief for the high speed
protection system may be considered by the FAA Flight Operations
Evaluation Board (FOEB) provided that the flight manual instructions
indicate reduced maximum operating speeds as described in paragraph 4.,
and that no additional hazards are introduced with the high speed
protection system inoperative. In addition, the cockpit display of the
reduced operating speeds, as well as the overspeed warning for
exceeding those speeds, must be equivalent to that of the normal
airplane with the high speed protection system operative.
Issued in Renton, Washington, on February 3, 2011.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2011-3412 Filed 2-15-11; 8:45 am]
BILLING CODE 4910-13-P