Airworthiness Directives; Gulfstream Aerospace Corporation Airplanes

[Federal Register Volume 91, Number 126 (Thursday, July 2, 2026)]
[Rules and Regulations]
[Pages 40363-40366]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-13476]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2026-4667; Project Identifier AD-2026-00584-T; 
Amendment 39-23392; AD 2026-13-51]
RIN 2120-AA64


Airworthiness Directives; Gulfstream Aerospace Corporation 
Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Gulfstream Aerospace Corporation Model GVIII-G700 and GVIII-
G800 airplanes. This AD was prompted by a report indicating that a 
hollow pin cap on the right-side engine aft thrust strut mount 
interface was found broken due to a missing sleeve bushing. This AD 
requires a visual inspection of the upper surface of the engine mount 
to the forward and aft thrust strut mount at the hollow pin head 
interface, of the left and right engines, for evidence of movement or 
distress; an inspection of the forward and aft thrust strut mount 
hardware to ensure the sleeve bushing, nut, washers, and cotter pins 
are properly installed; and applicable

[[Page 40364]]

corrective actions. The FAA previously sent an emergency AD to all 
known U.S. owners and operators of these airplanes. The FAA is issuing 
this AD to address the unsafe condition on these products.

DATES: This AD is effective July 17, 2026. Emergency AD 2026-13-51, 
issued on June 18, 2026, which contains the requirements of this 
amendment, was effective with actual notice.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of July 17, 
2026.
    The FAA must receive comments on this AD by August 17, 2026.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
    <bullet> Federal eRulemaking Portal: Go to regulations.gov. Follow 
the instructions for submitting comments.
    <bullet> Fax: 202-493-2251.
    <bullet> Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE, Washington, DC 20590.
    <bullet> Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2026-4667; or in person at Docket Operations between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD 
docket contains this final rule, any comments received, and other 
information. The street address for Docket Operations is listed above.
    Material Incorporated by Reference:
    <bullet> For Gulfstream Aerospace Corporation material identified 
in this AD, contact Gulfstream Aerospace Corporation, Technical 
Publications Dept., P.O. Box 2206, Savannah, GA 31402-2206; telephone 
800-810-4853; email [email protected]; website gulfstream.com/en/customer-support.
    <bullet> You may view this material at the FAA, Airworthiness 
Products Section, Operational Safety Branch, 2200 South 216th St., Des 
Moines, WA. For information on the availability of this material at the 
FAA, call 206-231-3195. It is also available at regulations.gov under 
Docket No. FAA-2026-4667.

FOR FURTHER INFORMATION CONTACT: Jeff Johnson, Senior Aviation Safety 
Engineer, FAA, 1701 Columbia Avenue, College Park, GA 30337; phone: 
404-474-5554; email: [email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites you to send any written relevant data, views, or 
arguments about this AD. Send your comments using a method listed under 
the ADDRESSES section. Include ``Docket No. FAA-2026-4667; Project 
Identifier AD-2026-00584-T'' at the beginning of your comments. The 
most helpful comments reference a specific portion of the final rule, 
explain the reason for any recommended change, and include supporting 
data. The FAA will consider all comments received by the closing date 
and may amend this final rule because of those comments.
    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 
regulations.gov, including any personal information you provide. The 
agency will also post a report summarizing each substantive verbal 
contact received about this final rule.

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 this AD contain commercial 
or financial information that is customarily treated as private, that 
you actually treat as private, and that is relevant or responsive to 
this AD, 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 they will not be placed in the public 
docket of this AD. Submissions containing CBI should be sent to Jeff 
Johnson, Senior Aviation Safety Engineer, FAA, 1701 Columbia Avenue, 
College Park, GA 30337; phone: 404-474-5554; email: [email protected]. 
Any commentary that the FAA receives that is not specifically 
designated as CBI will be placed in the public docket for this 
rulemaking.

Background

    The FAA issued Emergency AD 2026-13-51, dated June 18, 2026 (the 
emergency AD), to address an unsafe condition on certain Gulfstream 
Aerospace Corporation Model GVIII-G700 and GVIII-G800 airplanes. The 
FAA sent the emergency AD to all known U.S. owners and operators of 
these airplanes. The emergency AD requires a visual inspection of the 
upper surface of the engine mount to the forward and aft thrust strut 
mount at the hollow pin head interface, of the left and right engines, 
for evidence of movement or distress; an inspection of the forward and 
aft thrust strut mount hardware to ensure the sleeve bushing, nut, 
washers, and cotter pins are properly installed; and applicable 
corrective actions.
    The emergency AD was prompted by a report indicating that a hollow 
pin cap on the right-side engine aft thrust strut mount interface was 
found broken due to a missing sleeve bushing. Further investigation 
found the sleeve bushing was loose (displaced) within the engine pylon. 
The airplane had accumulated 1,056 total flight hours and 324 total 
flight cycles. During a subsequent audit, an additional airplane failed 
a gap check at the right-side engine forward thrust strut mount 
interface. The additional airplane had accumulated 551 total flight 
hours and 182 total flight cycles. The engine thrust struts on both 
airplanes were previously disconnected to perform production retrofit 
activities prior to entry into service. An improperly installed engine 
thrust strut could compromise the structural integrity of the engine 
mount system and lead to failure of the engine mount system. This 
condition, if not addressed, could result in an in-flight separation of 
the engine from the airplane, leading to loss of control of the 
airplane.

Material Incorporated by Reference Under 1 CFR Part 51

    The FAA reviewed Gulfstream GVIII-G700 Alert Customer Bulletin No. 
001, dated June 16, 2026; and Gulfstream GVIII-G800 Alert Customer 
Bulletin No. 001, dated June 16, 2026. This material specifies 
procedures for visually inspecting the upper surface of the engine 
mount to the forward and aft thrust strut mount at the hollow pin head 
interface, of the left and right engines, for evidence of movement or 
distress (i.e., paint abrasion or witness marks, gouging or surface 
damage, a broken or compromised hollow pin); inspecting the forward and 
aft thrust strut mount hardware to ensure the sleeve bushing, nut, 
washers, and cotter pins are properly installed; and depending on 
findings, submitting certain information to the manufacturer for 
further evaluation and engineering disposition (i.e., corrective 
action).
    This material is reasonably available because the interested 
parties have access to it through their normal course of business or by 
the means identified in the ADDRESSES section.

[[Page 40365]]

FAA's Determination

    The FAA is issuing this AD because the agency has determined the 
unsafe condition described previously is likely to exist or develop in 
other products of the same type design.

AD Requirements

    This AD requires accomplishing the actions specified in the 
material already described, except for any differences identified as 
exceptions in the regulatory text of this AD.

Interim Action

    The FAA considers this AD to be an interim action. If a final 
action is later identified, the FAA might consider further rulemaking 
then.

FAA's Justification and Determination of the Effective Date

    Section 553(b) of the Administrative Procedure Act (APA) (5 U.S.C. 
551 et seq.) authorizes agencies to dispense with notice and comment 
procedures for rules when the agency, for ``good cause,'' finds that 
those procedures are ``impracticable, unnecessary, or contrary to the 
public interest.'' Under this section, an agency, upon finding good 
cause, may issue a final rule without providing notice and seeking 
comment prior to issuance. Further, section 553(d) of the APA 
authorizes agencies to make rules effective in less than thirty days, 
upon a finding of good cause.
    An unsafe condition exists that required the immediate adoption of 
Emergency AD 2026-13-51 issued on June 18, 2026, to all known U.S. 
owners and operators of these airplanes. The FAA found that the risk to 
the flying public justified forgoing notice and comment prior to 
adoption of this rule because the urgency of the unsafe condition 
necessitates prohibiting further flight until the airplane is inspected 
and the applicable corrective actions are performed. These conditions 
still exist, and the AD is hereby published in the Federal Register as 
an amendment to 14 CFR 39.13 to make it effective to all persons. Given 
the significance of the risk presented by this unsafe condition, it 
must be immediately addressed. Accordingly, notice and opportunity for 
prior public comment are impracticable and contrary to the public 
interest pursuant to 5 U.S.C. 553(b).
    In addition, the FAA finds that good cause exists pursuant to 5 
U.S.C. 553(d) for making this amendment effective in less than 30 days, 
for the same reasons the FAA found good cause to forgo notice and 
comment.

Regulatory Flexibility Act (RFA)

    The requirements of the RFA do not apply when an agency finds good 
cause pursuant to 5 U.S.C. 553 to adopt a rule without prior notice and 
comment. Because the FAA has determined that it has good cause to adopt 
this rule without notice and comment, RFA analysis is not required.

Costs of Compliance

    The FAA estimates that this AD affects 37 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
               Action                         Labor cost            Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Inspections........................  20 work-hours x $85 per                  $0          $1,700         $62,900
                                      hour = $1,700.
----------------------------------------------------------------------------------------------------------------

    The FAA has received no definitive data on which to base the cost 
estimates for the on-condition actions specified in this AD.
    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some or all of the costs of 
this AD may be covered under warranty, thereby reducing the cost impact 
on affected operators.

Paperwork Reduction Act

    A federal agency may not conduct or sponsor, and a person is not 
required to respond to, nor shall a person be subject to a penalty for 
failure to comply with a collection of information subject to the 
requirements of the Paperwork Reduction Act unless that collection of 
information displays a currently valid OMB Control Number. The OMB 
Control Number for the collection of information required by this AD is 
2120-0056. The paperwork cost associated with this AD has been detailed 
in the Costs of Compliance section of this document and includes time 
for reviewing instructions, as well as completing and reviewing the 
collection of information. Therefore, all reporting associated with 
this AD is mandatory. Comments concerning the accuracy of this burden 
and suggestions for reducing the burden should be directed to: 
Information Collection Clearance Officer, Federal Aviation 
Administration, 10101 Hillwood Parkway, Fort Worth, TX 76177-1524.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII: Aviation Programs 
describes in more detail the scope of the Agency's authority.
    The FAA is issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701: General requirements. 
Under that section, Congress charges the FAA with promoting safe flight 
of civil aircraft in air commerce by prescribing regulations for 
practices, methods, and procedures the Administrator finds necessary 
for safety in air commerce. This regulation is within the scope of that 
authority because it addresses an unsafe condition that is likely to 
exist or develop on products identified in this rulemaking action.

Regulatory Findings

    This AD will not have federalism implications under Executive Order 
13132. This AD will not have a substantial direct effect on the States, 
on the relationship between the national government and the States, or 
on the distribution of power and responsibilities among the various 
levels of government.
    For the reasons discussed above, I certify that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866, and
    (2) Will not affect intrastate aviation in Alaska.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

[[Page 40366]]

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

2026-13-51 Gulfstream Aerospace Corporation: Amendment 39-23392; 
Docket No. FAA-2026-4667; Project Identifier AD-2026-00584-T.

(a) Effective Date

    The FAA issued Emergency Airworthiness Directive (AD) 2026-13-51 
on June 18, 2026 (also referred to as the emergency AD), directly to 
affected owners and operators. As a result of such actual notice, 
the emergency AD was effective for those owners and operators on the 
date it was received. This AD contains the same requirements as the 
emergency AD and, for those who did not receive actual notice, is 
effective on July 17, 2026.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Gulfstream Aerospace Corporation airplanes, 
certificated in any category, identified in paragraphs (c)(1) and 
(2) of this AD.
    (1) Model GVIII-G700 airplanes, serial numbers (S/Ns) 87002 
through 87049 inclusive, 87053, and 87076.
    (2) Model GVIII-G800 airplanes, S/Ns 88002 through 88014 
inclusive.

(d) Subject

    Air Transport Association (ATA) of America Code 71, Power Plant.

(e) Unsafe Condition

    This AD was prompted by a report indicating that a hollow pin 
cap on the right engine aft thrust strut was found broken due to a 
missing sleeve bushing. The FAA is issuing this AD to address an 
improperly installed engine thrust strut that could compromise the 
structural integrity of the engine mount system and lead to failure 
of the engine mount system. The unsafe condition, if not addressed, 
could result in an in-flight separation of the engine from the 
airplane, leading to loss of control of the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    Before further flight: Except as specified by paragraph (h) of 
this AD, do all applicable actions identified as ``RC'' (required 
for compliance) in, and in accordance with, the Accomplishment 
Instructions of Gulfstream GVIII-G700 Alert Customer Bulletin No. 
001, dated June 16, 2026; or Gulfstream GVIII-G800 Alert Customer 
Bulletin No. 001, dated June 16, 2026; as applicable.

(h) Exceptions to Service Information Specifications

    Where GVIII-G700 Alert Customer Bulletin No. 001, dated June 16, 
2026; and Gulfstream GVIII-G800 Alert Customer Bulletin No. 001, 
dated June 16, 2026; specify to submit certain information to 
Gulfstream for further evaluation and engineering disposition (i.e., 
corrective action) before aircraft can return to service: This AD 
requires doing the corrective action before further flight using a 
method approved in accordance with the procedures specified in 
paragraph (k) of this AD.

(i) Credit for Previous Actions

    This paragraph provides credit for the corresponding inspections 
specified in paragraph (g) of this AD, if those actions were 
performed before the effective date of this AD, using Gulfstream 
Technical Evaluation Discrepancy Sheet/Workorder, Control No. TE-26-
06-01, issued June 15, 2026.

(j) Special Flight Permit

    Special flight permits, as described in 14 CFR 21.197 and 
21.199, are not allowed.

(k) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, East Certification Branch, FAA, has the 
authority to approve AMOCs for this AD, if requested using the 
procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, 
send your request to your principal inspector or responsible Flight 
Standards Office, as appropriate. If sending information directly to 
the manager of the certification office, send it to the attention of 
the person identified in paragraph (l)(1) of this AD. Information 
may be emailed to: [email protected]. Before using any approved AMOC, 
notify your appropriate principal inspector, or lacking a principal 
inspector, the manager of the local flight standards district 
office/certificate holding district office.
    (2) An AMOC that provides an acceptable level of safety may be 
used for any repair, modification, or alteration required by this AD 
if it is approved by Gulfstream Engineering Authorized 
Representative (EAR) of the Gulfstream Organization Designation 
Authorization (ODA) that has been authorized by the Manager, East 
Certification Branch, FAA, to make those findings. To be approved, 
the repair method, modification deviation, or alteration deviation 
must meet the certification basis of the airplane, and the approval 
must specifically refer to this AD.
    (3) Except as specified by paragraph (h) of this AD: For 
material that contains steps that are labeled as RC, the provisions 
of paragraphs (k)(3)(i) and (ii) of this AD apply.
    (i) The steps labeled as RC, including substeps under an RC step 
and any figures identified in an RC step, must be done to comply 
with the AD. An AMOC is required for any deviations to RC steps, 
including substeps and identified figures.
    (ii) Steps not labeled as RC may be deviated from using accepted 
methods in accordance with the operator's maintenance or inspection 
program without obtaining approval of an AMOC, provided the RC 
steps, including substeps and identified figures, can still be done 
as specified, and the airplane can be put back in an airworthy 
condition.

(l) Additional Information

    (1) For more information about this AD, contact Jeff Johnson, 
Senior Aviation Safety Engineer, FAA, 1701 Columbia Avenue, College 
Park, GA 30337; phone: 404-474-5554; email: [email protected].
    (2) Material identified in this AD that is not incorporated by 
reference is available at the address specified in paragraph (m)(3) 
of this AD.

(m) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference of the material listed in this paragraph 
under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this material as applicable to do the actions 
required by this AD, unless the AD specifies otherwise.
    (i) Gulfstream GVIII-G700 Alert Customer Bulletin No. 001, dated 
June 16, 2026.
    (ii) Gulfstream GVIII-G800 Alert Customer Bulletin No. 001, 
dated June 16, 2026.
    (3) For Gulfstream Aerospace Corporation material identified in 
this AD, contact Gulfstream Aerospace Corporation, Technical 
Publications Dept., P.O. Box 2206, Savannah, GA 31402-2206; 
telephone 800-810-4853; email [email protected]; website 
gulfstream.com/en/customer-support.
    (4) You may view this material at the FAA, Airworthiness 
Products Section, Operational Safety Branch, 2200 South 216th St., 
Des Moines, WA. For information on the availability of this material 
at the FAA, call 206-231-3195.
    (5) You may view this material at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].

    Issued on June 25, 2026.
Christopher R. Parker,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2026-13476 Filed 7-1-26; 8:45 am]
BILLING CODE 4910-13-P

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