83 FR 4575 - Special Conditions: Gulfstream Aerospace Corporation Model GVII-G500 Airplanes; Operation Without Normal Electrical Power

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 83, Issue 22 (February 1, 2018)

These special conditions are issued for the Gulfstream Aerospace Corporation (Gulfstream) Model GVII-G500 airplane. This airplane will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport-category airplanes. This design feature is an electronic flight-control system, the functions of which are dependent upon the airplane's electrical power generation and distribution systems. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. 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.

[Federal Register Volume 83, Number 22 (Thursday, February 1, 2018)]
[Rules and Regulations]
[Pages 4575-4577]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2018-01963]



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Rules and Regulations
                                                Federal Register
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Federal Register / Vol. 83, No. 22 / Thursday, February 1, 2018 / 
Rules and Regulations

[[Page 4575]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2015-7290; Special Conditions No. 25-715-SC]


Special Conditions: Gulfstream Aerospace Corporation Model GVII-
G500 Airplanes; Operation Without Normal Electrical Power

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for the Gulfstream 
Aerospace Corporation (Gulfstream) Model GVII-G500 airplane. This 
airplane will have a novel or unusual design feature when compared to 
the state of technology envisioned in the airworthiness standards for 
transport-category airplanes. This design feature is an electronic 
flight-control system, the functions of which are dependent upon the 
airplane's electrical power generation and distribution systems. The 
applicable airworthiness regulations do not contain adequate or 
appropriate safety standards for this design feature. 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: This action is effective on Gulfstream on February 1, 2018. We 
must receive your comments by March 19, 2018.

ADDRESSES: Send comments identified by docket number FAA-2015-7290 
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 website, 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/ 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 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: Nazih Khaouly, FAA, Airplane and 
Flightcrew Interface Branch, ANM-111, Transport Airplane Directorate, 
Aircraft Certification Service, 1601 Lind Avenue SW, Renton, Washington 
98057-3356; telephone 425-227-2432; facsimile 425-227-1320.

SUPPLEMENTARY INFORMATION: The FAA has determined that notice of, and 
opportunity for prior public comment on, these special conditions is 
unnecessary because the substance of these special conditions has been 
subject to the public-comment process in several prior instances with 
no substantive comments received. 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 March 29, 2012, Gulfstream applied for a type certificate for 
their new Model GVII-G500 airplane. This transport-category, twin-
engine airplane will be a business jet capable of accommodating up to 
19 passengers. The maximum takeoff weight is 91,000 lbs.

Type Certification Basis

    Under Title 14, Code of Federal Regulations (14 CFR) 21.17, 
Gulfstream must show that the Model GVII-G500 airplane 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., part 25) do not contain adequate or appropriate 
safety standards for the Model GVII-G500 airplane because of a novel or 
unusual design feature, special conditions are prescribed under the 
provisions of 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 special 
conditions, Model GVII-G500 airplanes 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 issue a 
finding of regulatory adequacy under Sec.  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

[[Page 4576]]

the type certification basis under Sec.  21.17(a)(2).

Novel or Unusual Design Features

    The Model GVII-G500 airplane will incorporate the following novel 
or unusual design feature:
    An electronic flight-control system, the functions of which are 
dependent upon the electrical power-generation and distribution 
systems, whereby the loss of all electrical power may be catastrophic 
to the airplane. These special conditions retain the level of safety 
offered by 14 CFR 25.1351(d).

Discussion

    The Gulfstream Aerospace Corporation Model GVII-G500 airplane 
incorporates a fly-by-wire flight-control system that requires a 
continuous source of electrical power to keep the flight-control system 
operable. The current regulation, Sec.  25.1351(d), Amendment 25-72, 
``Operation without normal electrical power,'' states that the airplane 
must be operated safely in visual-flight-rules conditions for a period 
of not less than five minutes after loss of all normal electrical 
power. This rule was structured around a traditional design of 
mechanical control cables for flight control that allowed time for the 
crew to remedy an electrical failure, start the engine(s) if necessary, 
and re-establish some or all of the electrical power-generation 
capability.
    To maintain the same level of safety associated with traditional 
designs, the Model GVII-G500 airplane design must not be time limited 
in its operation when the airplane is without its normal source of 
engine- or auxiliary-power-unit-generated electrical power. Service 
experience has shown that the loss of all electrical power generated by 
an airplane's engine generators or auxiliary power unit (APU) is not 
extremely improbable. Likewise, regulations require the applicant to 
demonstrate that the airplane has the power required for continued safe 
flight and landing with the use of its emergency electrical power 
systems. These emergency electrical power systems must be able to power 
all loads considered essential for continued safe flight and landing.
    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.

Applicability

    As discussed above, these special conditions are applicable to the 
Gulfstream Model GVII-G500 airplane. 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 feature, these special 
conditions would apply to that model as well.

Conclusion

    This action affects only a certain novel or unusual design feature 
on one model series of airplanes. It is not a rule of general 
applicability.
    The substance of these special conditions has been subjected to the 
notice and comment period in several prior instances and has been 
derived without substantive change from those previously issued. It is 
unlikely that prior public comment would result in a significant change 
from the substance contained herein. Therefore, the FAA has determined 
that prior public notice and comment are unnecessary, and good cause 
exists for adopting these special conditions upon publication in the 
Federal Register.
    The FAA is requesting comments to allow interested persons to 
submit views that may not have been submitted in response to the prior 
opportunities for comment described above.

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

    Because the total loss of normal, generated, electrical power in 
two-engine airplanes is not extremely improbable, and because the loss 
of all electrical power may be catastrophic to airplanes equipped with 
an electronic flight-control system, the following special conditions 
apply to Gulfstream Model GVII airplanes.
    In lieu of Sec.  25.1351(d), the following special conditions 
apply:
    1. Gulfstream must show, by test or a combination of test and 
analysis, that the airplane is capable of continued safe flight and 
landing with all normal electrical power sources inoperative, as 
prescribed by paragraphs 1.a. and 1.b., below. For purposes of these 
special conditions, normal sources of electrical-power generation do 
not include alternate power sources such as the battery, ram-air 
turbine, or independent power systems such as the flight-control 
permanent-magnet generating system. In showing capability for continued 
safe flight and landing, Gulfstream must account for systems 
capability, effects on crew workload and operating conditions, and the 
physiological needs of the flightcrew and passengers for the longest 
diversion time for which Gulfstream is seeking approval.
    a. In showing compliance with this requirement, Gulfstream must 
account for common-cause failures, cascading failures, and zonal 
physical threats.
    b. Gulfstream may consider the ability to restore operation of 
portions of the electrical power generation and distribution system if 
it can be shown that unrecoverable loss of those portions of the system 
is extremely improbable. The design must provide an alternative source 
of electrical power for the time required to restore the minimum 
electrical-power generation capability required for safe flight and 
landing. Gulfstream may exclude unrecoverable loss of all engines when 
showing compliance with this requirement.
    2. Regardless of electrical-power generation and distribution-
system recovery capability shown under special condition 1, above, 
sufficient electrical-system capability must be provided to:
    a. Allow time to descend, with all engines inoperative, at the 
speed that provides the best glide distance, from the maximum operating 
altitude to the top of the engine-restart envelope, and
    b. Subsequently allow multiple start attempts of the engines and 
auxiliary power unit (APU). The design must provide this capability in 
addition to the electrical capability required by existing part 25 
requirements related to operation with all engines inoperative.
    3. The airplane emergency electrical-power system must be designed 
to supply:
    a. Electrical power required for immediate safety, which must 
continue to operate without the need for crew action following the loss 
of the normal electrical power, for a duration sufficient to allow 
reconfiguration to provide a non-time-limited source of electrical 
power.
    b. Electrical power required for continued safe flight and landing 
for the maximum diversion time.
    4. If the applicant uses APU-generated electrical power to satisfy 
the requirements of these special conditions, and if reaching a 
suitable runway for landing is beyond the capacity of the battery 
systems, then the APU must be able to be started under any foreseeable 
flight condition prior to the depletion of the battery, or the 
restoration of normal electrical power, whichever occurs first. Flight 
test must demonstrate this capability at the most critical condition.
    a. The applicant must show that the APU will provide adequate 
electrical power for continued safe flight and landing.

[[Page 4577]]

    b. The airplane flight manual (AFM) must incorporate abnormal 
procedures that direct the pilot to take appropriate actions to 
activate the APU after loss of normal engine-driven generated 
electrical power.
    5. As part of showing compliance with these special conditions, the 
tests to demonstrate loss of all normal electrical power must also take 
into account the following:
    a. The assumption that the failure condition occurs during night 
instrument meteorological conditions (IMC) at the most critical phase 
of the flight, relative to the worst possible electrical-power 
distribution and equipment-loads-demand condition.
    b. After an unrestorable loss of normal engine-driven generated 
electrical power, the airplane engine-restart capability is provided 
and operations are continued in IMC.
    c. The airplane is demonstrated to be capable of continued safe 
flight and landing. The duration of this capability must be computed 
based on the maximum diversion-time capability for which the airplane 
is being certified. The applicant must account for airspeed reductions 
resulting from the associated failure or failures.
    d. The airplane must provide adequate indication of loss of normal 
electrical power to direct the pilot to the abnormal procedures, and 
the AFM must incorporate abnormal procedures that will direct the pilot 
to take appropriate actions.

    Issued in Renton, Washington, on January 11, 2018.
Victor Wicklund,
Manager, Transport Standards Branch, Policy and Innovation Division, 
Aircraft Certification Service.
[FR Doc. 2018-01963 Filed 1-31-18; 8:45 am]
 BILLING CODE 4910-13-P