[Federal Register Volume 89, Number 20 (Tuesday, January 30, 2024)]
[Rules and Regulations]
[Pages 5760-5762]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-01740]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2023-2439; Special Conditions No. 25-852-SC]


Special Conditions: Gulfstream Aerospace Corporation Model GVIII-
G700 and GVIII-G800 Series 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 GVIII-G700 and GVIII-G800 
series airplanes. These airplanes 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 electrical power-generation and distribution 
systems, whereby the loss of all electrical power may be catastrophic 
to the airplane. 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 January 30, 2024. Send 
comments on or before March 15, 2024.

ADDRESSES: Send comments identified by Docket No. FAA-2023-2439 using 
any of the following methods:
     Federal eRegulations Portal: Go to 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.

[[Page 5761]]

     Docket: Background documents or comments received may be 
read at 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: Dan Poblete, Aircraft Systems, AIR-
623, Technical Innovation Policy Branch, Policy and Innovation 
Division, Aircraft Certification Service, Federal Aviation 
Administration, 3960 Paramount Boulevard, Suite 100, Lakewood, 
California 90712; telephone 562-627-5335, fax 562-627-5210; email 
[email protected].

SUPPLEMENTARY INFORMATION: The substance of these special conditions 
has been published in the Federal Register for public comment in 
several prior instances with no substantive comments received. 
Therefore, the FAA finds, pursuant to 14 CFR 11.38(b), that new 
comments are unlikely, and notice and comment prior to this publication 
are unnecessary.

Privacy

    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in 14 CFR 
11.35, the FAA will post all comments received without change to 
www.regulations.gov, including any personal information you provide. 
The FAA will also post a report summarizing each substantive verbal 
contact received about these special conditions.

Confidential Business Information

    Confidential Business Information (CBI) is commercial or financial 
information that is both customarily and actually treated as private by 
its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), 
CBI is exempt from public disclosure. If your comments responsive to 
these special conditions contain commercial or financial information 
that is customarily treated as private, that you actually treat as 
private, and that is relevant or responsive to these special 
conditions, it is important that you clearly designate the submitted 
comments as CBI. Please mark each page of your submission containing 
CBI as ``PROPIN.'' The FAA will treat such marked submissions as 
confidential under the FOIA, and the indicated comments will not be 
placed in the public docket of these special conditions. Send 
submissions containing CBI to the individual listed in the For Further 
Information Contact section above. Comments the FAA receives, which are 
not specifically designated as CBI, will be placed in the public docket 
for these special conditions.

Comments Invited

    The FAA invites 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.
    The FAA will consider all comments received by the closing date for 
comments and will consider comments filed late if it is possible to do 
so without incurring delay. The FAA may change these special conditions 
based on the comments received.

Background

    On December 31, 2019, Gulfstream applied for an amendment to Type 
Certificate No. T00015AT to include the new Model GVIII-G700 and GVIII-
G800 series airplanes. These airplanes, which are derivatives of the 
Model GVI currently approved under Type Certificate No. T00015AT, are 
twin-engine, transport-category airplanes, with seating for 19 
passengers, and a maximum take-off weight of 107,600 pounds (GVIII-
G700) and 105,600 pounds (GVIII-G800).

Type Certification Basis

    Under the provisions of title 14, Code of Federal Regulations (14 
CFR) 21.101, Gulfstream must show that the Model GVIII-G700 and GVIII-
G800 series airplanes meet the applicable provisions of the regulations 
listed in Type Certificate No. T00015AT, or the applicable regulations 
in effect on the date of application for the change, except for earlier 
amendments as agreed upon by the FAA.
    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 GVIII-G700 and 
GVIII-G800 series airplanes 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 novel or 
unusual design feature, or should any other model already included on 
the same type certificate be modified to incorporate the same novel or 
unusual design feature, these special conditions would also apply to 
the other model under Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the Gulfstream Model GVIII-G700 and GVIII-G800 series 
airplanes must comply with the 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 14 CFR 11.38, and they become part of the type 
certification basis under Sec.  21.101.

Novel or Unusual Design Features

    The Gulfstream Model GVIII-G700 and GVIII-G800 series airplanes 
will incorporate the following novel or unusual design feature:
    This design feature is 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 Sec.  25.1351(d).

Discussion

    The Gulfstream Aerospace Corporation Model GVIII-G700 and GVIII-
G800 airplanes incorporate 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 GVIII-G700 and GVIII-G800 airplane's 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

[[Page 5762]]

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 GVIII-G700 and GVIII-G800 series airplanes. 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 Gulfstream Model GVIII-G700 and GVIII-G800 series of airplanes. It 
is not a rule of general applicability.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.

Authority Citation

    The authority citation for these special conditions is as follows:

    Authority:  49 U.S.C. 106(f), 106(g), 40113, 44701, 44702, and 
44704.

The Special Conditions

    [ssquf] 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 Model GVIII-G700 and 
GVIII-G800 series airplanes.
    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 GVIII-G700 and GVIII-G800 airplanes.
    (a) 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)(i) and (1)(ii), 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.
    (i) In showing compliance with this requirement, Gulfstream must 
account for common-cause failures, cascading failures, and zonal 
physical threats.
    (ii) 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:
    (i) 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
    (ii) 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:
    (i) 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.
    (ii) 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 
tests must demonstrate this capability at the most critical condition.
    (i) The applicant must show that the APU will provide adequate 
electrical power for continued safe flight and landing.
    (ii) 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:
    (i) 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.
    (ii) After an unrestorable loss of normal engine-driven generated 
electrical power, the airplane engine-restart capability is provided, 
and operations are continued in IMC.
    (iii) 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.
    (iv) 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 Kansas City, Missouri, on January 24, 2024.
Patrick R. Mullen,
Manager, Technical Innovation Policy Branch, Policy and Innovation 
Division, Aircraft Certification Service.
[FR Doc. 2024-01740 Filed 1-29-24; 8:45 am]
BILLING CODE 4910-13-P