[Federal Register Volume 89, Number 52 (Friday, March 15, 2024)]
[Rules and Regulations]
[Pages 18767-18769]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-05661]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2023-2437; Special Conditions No. 25-858-SC]


Special Conditions: Gulfstream Aerospace Corporation Model GVIII-
G700 and GVIII-G800 Series Airplanes; Flight Envelope Protection: 
Takeoff Stall Protection

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions.

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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 envelope protection function to protect the airplane from 
over- and rapid-rotation on takeoff. 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: Effective March 15, 2024.

FOR FURTHER INFORMATION CONTACT: Troy Brown, Performance and 
Environment Unit, AIR-621A, Technical Policy Branch, Policy and 
Standards Division, Aircraft Certification Service, Federal Aviation 
Administration, 1801 S Airport Rd., Wichita, KS 67209-2190; telephone 
and fax 405-666-1050; email [email protected].

SUPPLEMENTARY INFORMATION:

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 will be 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 (e.g., 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

[[Page 18768]]

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 airplanes will 
incorporate the following novel or unusual design feature:
    An envelope protection function within the electronic flight 
control system (EFCS) to protect the airplane from over- and rapid-
rotation on takeoff.

Discussion

    The Gulfstream Model GVIII-G700 and GVIII-G800 series airplanes are 
equipped with an envelope protection function within the EFCS that is 
designed to provide enhanced takeoff stall protection (TSP) function. 
This feature protects against excessive pitch rate and pitch attitude 
during takeoff using a limitation in the electronic flight controls. It 
is designed to provide conventional behavior using a normal takeoff 
technique, including ``performance'' takeoffs. The limit to pitch 
attitude will indirectly limit the angle of attack.
    The TSP involves a control law update in the on-ground control mode 
only. The Model GVIII-G700 and GVIII-G800 series airplane's pitch 
control behavior, with regard to rotation rates and attitudes for 
normal takeoffs, will be similar to other Gulfstream airplanes equipped 
with side sticks; however, takeoffs with rapid rotation rates and over-
rotation will be influenced by the TSP.
    The current regulations in Subpart B of 14 CFR part 25 do not 
address envelope protections for electronic flight control systems as 
this technology is novel or unusual for transport category airplanes. 
These special conditions are specific to the GVIII-G700 and GVIII-G800 
series airplanes. These conditions are necessary to ensure that the TSP 
function supports safe operation and does not interfere with required 
maneuvering in normal and emergency operations and in foreseeable 
atmospheric conditions.
    The 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.

Discussion of Comments and Final Special Conditions

    The FAA issued Notice of Proposed Special Conditions No. 25-24-01-
SC, for the GVIII-G700 and GVIII-G800 series airplanes. This Notice was 
published in the Federal Register on January 18, 2024 (89 FR 3364). The 
only comment the FAA received was from the applicant (Gulfstream).
    Gulfstream requested that the FAA revise the third paragraph of the 
Discussion section, to better reflect the content and scope of the 
proposed special conditions. The FAA agrees with this comment as it 
aligns with proposed regulation text from the Flight Test Harmonization 
Working Group Phase 2 Rev A Final Report. The identified text has been 
revised in a manner consistent with Gulfstream's request.\1\
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    \1\ Specifically, the Discussion in Notice contained the 
following text: ``These special conditions are specific to the 
GVIII-700 and GVIII-G800 series airplanes. These conditions are 
necessary to ensure a smooth transition from normal flight to the 
TSP mode and adequate maneuver capability. These conditions also 
ensure that the structural limits of the airplane are not exceeded. 
Furthermore, failure of the TSP function must not create hazardous 
flight conditions.'' This text is replaced in these final special 
conditions with: ``These special conditions are specific to the 
Takeoff Stall Protection Function of the GVIII-G700 and GVIII-G800 
series airplanes. These conditions are necessary to ensure that the 
TSP function supports safe operation and does not interfere with 
required maneuvering in normal and emergency operations and in 
foreseeable atmospheric conditions.''
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    Gulfstream requested that the FAA remove certain text from the 
first paragraph of the Discussion section. The FAA finds that the 
referenced text is unnecessary for the Discussion and has removed it in 
these final special conditions.
    Gulfstream requested that the FAA revise the text of the Special 
Conditions section (i.e., the requirements) to align with the text of 
the Flight Test Harmonization Working Group Phase 2 Rev A Final 
Report.\2\ The primary difference is that the proposed special 
conditions included terms applicable to the ``takeoff stall protection 
function,'' but the term in the Report, which Gulfstream requested to 
be used, is the more general ``envelope protection function.'' The FAA 
agrees with Gulfstream's request to make this change for consistency 
with the terminology in the Report; but notes that the design feature 
being addressed by these special conditions remains the same as 
proposed. The FAA has also added ``simultaneous'' to the beginning of 
paragraph (e) as a final conformance with the requested text of the 
Report.
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    \2\ The Report is available at https://www.faa.gov/regulations_policies/rulemaking/committees/documents/media/09%20-%20FTHWG_Final_Report_Phase_2_RevA__Apr_2017.pdf; the requested text 
is at pages 43 and 221, and discussed beginning at page 238.
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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 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 apply to the other model 
as well.
    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 Gulfstream 
Model GVIII-G700 and GVIII-G800 is imminent, the FAA finds that good 
cause exists to make these special conditions effective upon 
publication.

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, 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 the Gulfstream Model GVIII-G700 and 
GVIII-G800 series airplanes, and will be applied by the FAA to the 
extent necessary to certify the envelope protection function within the 
electronic flight control system (EFCS) that protects the airplane from 
over- and rapid-rotation on takeoff.
    For airplanes that employ envelope protection functions:
    (a) Envelope protection functions must not unduly limit the 
maneuvering capability of the airplane nor interfere with its ability 
to perform maneuvers

[[Page 18769]]

required for normal and emergency operations.
    (b) Onset characteristics of each envelope protection function must 
be appropriate to the phase of flight and type of maneuver and must not 
conflict with the ability of the pilot to satisfactorily control the 
airplane flight path, speed, or attitude.
    (c) Excursions of a limited flight parameter beyond its nominal 
design limit value due to dynamic maneuvering, airframe and system 
tolerances, and non-steady atmospheric conditions must not result in 
unsafe flight characteristics or conditions.
    (d) Operation of envelope protection functions must not adversely 
affect aircraft control during expected levels of atmospheric 
disturbances, nor impede the application of recovery procedures in case 
of windshear.
    (e) Simultaneous activation of envelope protection functions must 
not result in adverse coupling or adverse priority.
    (f) In case of abnormal attitude or excursion of any flight 
parameters outside the protected boundaries, operation of envelope 
protection functions must not hinder airplane recovery.

    Issued in Kansas City, Missouri, on March 12, 2024.
James David Foltz,
Manager, Technical Policy Branch, Policy and Standards Division, 
Aircraft Certification Service.
[FR Doc. 2024-05661 Filed 3-13-24; 11:15 am]
BILLING CODE 4910-13-P