[Federal Register Volume 79, Number 170 (Wednesday, September 3, 2014)]
[Rules and Regulations]
[Pages 52169-52171]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-20865]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2014-0419; Special Conditions No. 25-563-SC]
Special Conditions: Gulfstream Aerospace Corporation, Model GVI;
Electro-Hydraulically Actuated Seats Equipped With a Backup Power
Supply
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special condition; request for comments.
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SUMMARY: These special conditions are issued for Gulfstream Aerospace
Corporation Model GVI airplane. This airplane, as modified by
Gulfstream Aerospace Corporation, will have novel or unusual design
features associated with the installation of electro-hydraulically
operated seats with a backup power supply (BPS) and hydraulic
reservoir, pump, and actuators, as well as massage and heating
functions. The applicable airworthiness regulations do not contain
adequate or appropriate safety standards for these design features.
These 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: The effective date of these special conditions is September 3,
2014. We must receive your comments by October 20, 2014.
ADDRESSES: Send comments identified by docket number FAA-2014-0419
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.
[[Page 52170]]
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: Dan Jacquet, FAA, Airframe and Cabin
Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft
Certification Service, 1601 Lind Avenue SW., Renton, Washington 98057-
3356; telephone 425-227-2676; facsimile 425-227-1320.
SUPPLEMENTARY INFORMATION: The FAA has determined that notice of, and
opportunity for prior public comment on, these special conditions is
impracticable because these procedures would significantly delay
issuance of the design approval and thus delivery of the affected
aircraft. The FAA therefore finds that good cause exists for making
these special conditions effective upon publication in the Federal
Register.
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 will consider all comments we receive by the closing date for
comments. We may change these special conditions based on the comments
we receive.
Background
On June 14, 2014, Gulfstream Aerospace Corporation applied for an
amendment to a Supplemental Type Certificate (STC) ST04252AT-D for the
installation of electro-hydraulically operated seats with novel or
unusual features in the Model GVI airplane. These features include a
backup power supply used to return the backrest, seat pan, and leg rest
to the taxi, takeoff, and landing (TT&L) position in the event of a
power failure. In addition, each seat contains a hydraulic reservoir,
pump, and actuators, as well as massage and heating functions. The
Model GVI is a business jet airplane powered by two Rolls-Royce
Deutschland Ltd. and Company KG turbofan engines and is certified for
19 passengers and a crew of 3.
Type Certification Basis
Under the provisions of Title 14, Code of Federal Regulation (14
CFR) 21.101, Gulfstream Aerospace Corporation must show that the Model
GVI, as changed, continues to meet the applicable provisions of the
regulations incorporated by reference in Type Certificate No. T00015AT
or the applicable regulations in effect on the date of application for
the change. The regulations incorporated by reference in the type
certificate are commonly referred to as the ``original type
certification basis.'' The regulations incorporated by reference in
Type Certificate No. T00015AT are as follows:
14 CFR part 25, Airworthiness Standards: Transport
Category Airplanes, effective February 1, 1965, including Amendments
25-1 through 25-120 and 25-122, 25-124, and 25-132. Amendment 25-118
was not published and therefore has no applicability.
14 CFR part 36, Noise Standards: Aircraft Type and
Airworthiness Certification, effective December 1, 1969, including
Amendments 36-1 through 36-28.
Compliance with Section 44715(e) of Title 49 U.S.C. (Noise
Control Act of 1972).
Optional Design Regulations:
(a) The Model GVI has been shown to comply with the requirements
for ditching: Sec. Sec. 25.801, 25.563, 25.807(e), and 25.1585(a).
When the operating rules require emergency ditching equipment,
compliance with Sec. Sec. 25.1411 and 25.1415 must be shown.
Gulfstream Report GVI-GER-1709, ``Design Requirements Document for
Ditching Equipment,'' provides an acceptable means for showing
compliance with Sec. Sec. 25.1411 and 25.1415.
(b) The Model GVI is approved for flight into known icing
conditions and has demonstrated compliance to Sec. 25.1419.
Exemptions pertinent to these special conditions:
Exemption No. 9761, Sec. Sec. 25.562(a) and 25.785(b), Side Facing
Divan.
In addition, the certification basis includes certain special
conditions, exemptions, and equivalent safety findings that are not
relevant to these proposed special conditions.
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 Gulfstream Model GVI because of a
novel or unusual design feature, special conditions are prescribed
under the provisions of 14 CFR 21.16.
Special conditions are initially applicable to the model for which
they are issued. Should the applicant apply for a STC to modify any
other model included on the same type certificate to incorporate the
same novel or unusual design feature, the special conditions would also
apply to the other model.
In addition to the applicable airworthiness regulations and special
conditions, the Gulfstream Model 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 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 14 CFR 21.101.
Novel or Unusual Design Features
The Gulfstream Model GVI will incorporate the following novel or
unusual design features: Hydraulically-actuated components on airplane
seats including hydraulic reservoir, pump, and actuators, as well as
massage and heating functions and backup power systems.
Discussion
Hydraulically-actuated components and backup power systems on
airplane seats are considered novel or unusual by the FAA. Therefore,
we developed special conditions that contain the additional standards
that the Administrator considers necessary to establish a level of
safety equivalent to that established by the existing airworthiness
standards.
The FAA has considered the installation of seats with these
features to have four primary safety concerns:
[[Page 52171]]
1. Reliability of the backup power supply;
2. Safety hazards to the occupants from the hydraulically-actuated
components of the seat;
3. Structural integrity of the hydraulic components; and
4. Flammability.
Emergency exits must be accessible to the passengers and the
effectiveness of evacuation must be maintained. Typical airplane seats
can be manually positioned to the lateral (track) and directional
(swivel) TT&L position by mechanical means, so they can be positioned
in the event of a loss of cabin power. For this electro-hydraulically
operated seat design, in lieu of a manual means to re-position the
hydraulically operated seat features (backrest, seat pan, and leg rest
deployment) for TT&L, a BPS is used to temporarily power the hydraulic
system. The BPS is only intended for use in the event of a loss of
cabin power. If the seats are installed in the path of the emergency
over wing exits, failure to return the seat to a TT&L position may have
an adverse effect on evacuation. Substantiation of 14 CFR 25.809(b) and
25.813(c)(2)(ii) must be shown with the seats in their most adverse
positions.
It must be shown that the hydraulically-actuated components of the
seat pose no safety hazard to the occupants or airplane. This includes
injuries caused by crushing of airplane occupants who are between the
hydraulically-actuated components and any part of the passenger cabin
when seat features (e.g., leg rest or backrest) are actuated.
Additionally, the risk of loss of function of a control or proximity
switch resulting in the pump motor being commanded to stay on, after
the hydraulic actuator(s) have reached their maximum/minimum limit,
must not cause the overloaded motor to overheat, as it could catch
fire.
The FAA has also considered the emergency landing dynamic
conditions for the installation of electro-hydraulically actuated
seats. The applicant must show that the hydraulic system (actuators,
reservoir, lines, etc.) remains intact and free from leakage under the
conditions specified in Sec. 25.562. Testing of each seat's hydraulic
system per Sec. 25.1435(c) may be conducted off of the airplane.
Flammability of hydraulic fluid used in the seat movement mechanism
must be considered. If the fluid is flammable, it could contribute to a
post-crash or in-flight fire. Any failure modes that would result in
release of the flammable hydraulic fluid during a post-crash or in-
flight fire causing such fluid to materially increase an existing fire
must be examined. Examples of this could be flex lines burning through
and releasing the flammable hydraulic fluid, or the fluid reservoir
could be heated in a fire resulting in a boiling liquid expanding vapor
explosion. The potential for spontaneous ignition of the fluid coming
into contact with hot surfaces or other ignition sources should also be
addressed. The applicant should examine any possible failure mode in
which the flammable hydraulic fluid could be absorbed into materials,
like the seat foam/fabric, carpeting, etc. The applicant must show that
any fluid-soaked seat parts are still self-extinguishing. The applicant
must also show that flammability of dry residue, which may be present
from a slow leak/fluid weepage, does not degrade the flammability
characteristics of any materials it may come into contact with to a
level below the requirements specified in Sec. 25.853.
Applicability
As discussed above, these special conditions are applicable to STC
ST04252AT-D, which modifies the Gulfstream Model GVI airplane. Should
Gulfstream Aerospace Corporation apply at a later date to amend this
STC to incorporate the same novel or unusual design feature, the
special conditions would apply to that amended STC as well.
Conclusion
This action affects only certain novel or unusual design features
on one airplane model. It is not a rule of general applicability and
affects only the applicant who applied to the FAA for approval of these
features on the airplane.
Under standard practice, the effective date of final special
conditions would be 30 days after the date of publication in the
Federal Register; however, as the certification date for the
modification to the Gulfstream Model GVI airplane is imminent, the FAA
finds that good cause exists to make these special conditions effective
upon publication in the Federal Register.
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 Special Conditions
Accordingly, pursuant to the authority delegated to me by the
Administrator, the following special conditions are issued as part of
the type certification basis for Gulfstream Aerospace Corporation
airplanes modified by Gulfstream Aerospace Corporation.
Electro-Hydraulically Actuated Seats Equipped With a Backup Power
Supply
1. The probability of failure of the backup power supply to return
seat components to the required taxi, takeoff, and landing position
must be shown to be no greater than 10-5 per flight hour.
2. It must be shown that the hydraulically-actuated components of
the seat pose no safety hazard to the occupants. Hazards to be
considered per the latest revision of Advisory Circular 25.1309-1, at a
minimum are:
a. Injuries caused by crushing of airplane occupants who are
between the hydraulically actuated components and any part of the
passenger cabin when the leg rest or backrest is actuated.
b. The risk of loss of function of a control or proximity switch
resulting in the pump motor being commanded to stay on after the
hydraulic actuator(s) have reached their maximum/minimum limit,
creating potential for overheat or fire.
c. The potential for a significant contribution to a fire in the
event fluid comes into contact with hot surfaces or other ignition
sources, and the potential for release of toxic or flammable vapors/
gasses.
3. It must be shown that the hydraulic system (actuators,
reservoir, lines, etc.) remains intact and free from leakage under the
conditions specified in Sec. 25.562. Testing of each seat's hydraulic
system per Sec. 25.1435(c) may be conducted off of the airplane.
4. Section 25.863 requires consideration of any effects the fluid,
including the fluid as a dry residue, could have on combustible or
absorbing materials. The characteristics of the flammable fluid in
these conditions must be tested to the requirements of Sec. 25.853(a)
and (c), or the materials must be shielded in a manner that prevents
contact by the fluid. However, as an alternative to such testing or
shielding, the applicant may provide, in accordance with Sec.
25.863(c), a quick-acting means that alerts the crew that the fluid has
leaked.
Issued in Renton, Washington, on August 26, 2014.
Michael Kaszycki,
Assistant Manager, Transport Airplane Directorate, Aircraft
Certification Service.
[FR Doc. 2014-20865 Filed 9-2-14; 8:45 am]
BILLING CODE 4910-13-P