Background The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to all Gulfstream Aerospace Corporation Model GVII-G500 and GVII-G600 airplanes. The NPRM was published in the Federal Register on June 30, 2025 (90 FR 27824). The NPRM was prompted by a determination that new and more restrictive airworthiness limitations are necessary. In the NPRM, the FAA proposed to revise the existing maintenance or inspection program, as applicable, to incorporate new and more restrictive airworthiness limitations. The FAA is issuing this AD to prevent failure of principal structural elements throughout the service life of each part. This condition, if not addressed, could compromise the structural integrity of the airplane. Discussion of Final Airworthiness Directive Comments The FAA received comments from Aery Aviation and Gulfstream. The following presents the comments received on the NPRM and the FAA's response to each comment. Request To Increase the Labor Rate Aery Aviation stated that the labor rate used in the proposed AD does not accurately reflect the cost to implement the proposed AD, particularly for airplanes maintained by the airplane manufacturer. The commenter stated the Gulfstream labor rate currently ranges from $250 to $322 per hour. The commenter recommended using Gulfstream's published labor rates for executive/private jets. The FAA notes that the current wage rate for aviation mechanics as provided by the Bureau of Labor Statistics, found at data.bls.gov/oesprofile , after accounting for fringe benefits that are valued at roughly 50% of the nominal wage, is lower than the estimated fully burdened labor rate of $85 per hour. Therefore, the FAA is unable to justify increasing the labor rate above $85 per hour. The FAA has not revised this AD in this regard. Request To Clarify What Prompted the Proposed AD Gulfstream requested the FAA revise the Background section of the proposed AD to specify the FAA received a report that the airworthiness limitations section of the Gulfstream GVII-G500 and GVII-G600 aircraft maintenance manuals (AMMs) has been revised to correct a typographical error for the main landing gear (MLG) cross bolt part number and to clarify safe life limit part numbers where "& Sub" was previously noted. Gulfstream also requested the FAA revise paragraph (e) of the proposed AD to specify the proposed AD was prompted by that report. Gulfstream said the statements in the Background section of the proposed AD regarding incorrect part numbers and new safe life limits, and in paragraph (e) of proposed AD regarding the FAA's determination that new and more restrictive airworthiness limitations are necessary, are vague and may be misleading. Gulfstream asserted these statements should revised for better clarity and to align with the actual reported condition. The FAA agrees to clarify that the report indicated the airworthiness limitations section (ALS) of the AMMs were revised to correct an error for the MLG cross bolt part number and to add safe life limit part numbers that were incorrectly assumed as included under the "& sub" family of parts. However, the FAA disagrees with revising this AD. The FAA considers differences between the FAA-approved engineering data and the technical publications to be errors. The MLG cross bolt part number was revised, and the safe life limit part numbers were expanded, because the ALS of the AMMs did not match the FAA-approved engineering data. Further, the FAA determined that these changes to ALS of the AMMs constitute new and more restrictive airworthiness limitations, and this AD was prompted by that determination. Request To Reference Later AMM Revisions Gulfstream requested that the FAA revise paragraphs (g) and (l) of the proposed AD to reference Section 05-10-10, "Airworthiness Limitations," Chapter 05, "Time Limits/Maintenance Checks," Gulfstream GVII-G500 AMM, Revision 20, dated April 15, 2025; and Gulfstream GVII-G600 AMM, Revision 16, dated April 15, 2025. Gulfstream stated paragraph (g) of the proposed AD would require incorporating earlier AMM revisions, without accommodating these later AMM revisions. Gulfstream noted that Revision 20 of the Gulfstream GVII-G500 AMM and Revision 16 of the Gulfstream GVII-G600 AMM incorporate additional guidance for airplanes operating under European Union Part-26/EASA Certification Specifications 26 and do not modify any of the airworthiness limitations related to the proposed AD. Gulfstream expressed concern that operators who have incorporated later AMM revisions would not be able to demonstrate compliance with the proposed AD unless they obtained an alternative method of compliance (AMOC). Gulfstream also stated that paragraph (l) of the proposed AD would require incorporating by reference the entire AMM, whereas only the airworthiness limitations in Section 05-10-10 are necessary to address the unsafe condition. The FAA agrees to revise paragraph (g) of this AD to clarify that using a later revision of Section 05-10-10 of the applicable AMM is acceptable for compliance with the requirements of paragraph (g) of this AD, provided that the information in the later revision is identical to that contained in Section 05-10-10, "Airworthiness Limitations," Chapter 05, "Time Limits/Maintenance Checks," Gulfstream GVII-G500 AMM, Revision 18, dated March 29, 2024; and Section 05-10-10, "Airworthiness Limitations," Chapter 05, "Time Limits/Maintenance Checks," Gulfstream GVII-G600 AMM, Revision 14, dated March 29, 2024; as applicable. As long as the information in the later revision of the applicable AMM is identical, an operator can show compliance with those airworthiness limitations without having to obtain an AMOC. The FAA disagrees with Gulfstream's interpretation that this AD mandates the entire AMM. The FAA notes that paragraph (g) of this AD mandates Section 05-10-10 of the Gulfstream GVII-G500 AMM, Revision 18, dated March 29, 2024; and Section 05-10-10, "Airworthiness Limitations," Chapter 05, "Time Limits/Maintenance Checks," Gulfstream GVII-G600 AMM, Revision 14, dated March 29, 2024; as applicable. Accordingly, paragraphs (l)(2)(i) and (ii) of this AD incorporate by reference that same service information. It is not necessary to reference Revision 20 of the Gulfstream GVII-G500 AMM and Revision 16 of the Gulfstream GVII-G600 AMM in paragraph (l) of this AD because these later revisions are not required for compliance and are instead referenced as acceptable methods of compliance with the requirements in paragraph (g) of this AD. Therefore, the FAA has not revised paragraph (l) of this AD in response to this comment. Conclusion The FAA reviewed the relevant data, considered any comments received, and determined that air safety requires adopting this AD as proposed. Accordingly, the FAA is issuing this AD to address the unsafe condition on these products. Except for minor editorial changes, and any other changes described previously, this AD is adopted as proposed in the NPRM. None of the changes will increase the economic burden on any operator. Material Incorporated by Reference Under 1 CFR Part 51 The FAA reviewed Section 05-10-10, "Airworthiness Limitations," Chapter 05, "Time Limits/Maintenance Checks," Gulfstream GVII-G500 AMM, Revision 18, dated March 29, 2024; and Section 05-10-10, "Airworthiness Limitations," Chapter 05, "Time Limits/Maintenance Checks," Gulfstream GVII-G600 AMM, Revision 14, dated March 29, 2024. This material specifies more restrictive airworthiness limitations and includes new safe life limit part numbers. These documents are distinct since they apply to different airplane models. 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. Costs of Compliance The FAA estimates that this AD affects 278 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD: The FAA has determined that revising the existing maintenance or inspection program takes an average of 90 work-hours per operator, although the agency recognizes that this number may vary from operator to operator. Since operators incorporate maintenance or inspection program changes for their affected fleet(s), the FAA has determined that a per-operator estimate is more accurate than a per-airplane estimate. Therefore, the FAA estimates the average total cost per operator to be $7,650 (90 work-hours × $85 per work-hour). 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, (2) Will not affect intrastate aviation in Alaska, and (3) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. The Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: PART 39-AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 [Amended] 2. The FAA amends § 39.13 by adding the following new airworthiness directive: 2026-01-03 Gulfstream Aerospace Corporation: Amendment 39-23231; Docket No. FAA-2025-1349; Project Identifier AD-2025-00310-T. (a) Effective Date This airworthiness directive (AD) is effective February 24, 2026. (b) Affected ADs None. (c) Applicability This AD applies to all Gulfstream Aerospace Corporation Model GVII-G500 and GVII-G600 airplanes, certificated in any category. (d) Subject Air Transport Association (ATA) of America Code 32, Main Landing Gear. (e) Unsafe Condition This AD was prompted by a determination that new and more restrictive airworthiness limitations are necessary. The FAA is issuing this AD to prevent failure of principal structural elements throughout the service life of each part. This condition, if not addressed, could compromise the structural integrity of the airplane. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Maintenance or Inspection Program Revision Within 30 days after the effective date of this AD, revise the existing maintenance or inspection program, as applicable, to incorporate the information specified in Section 05-10-10, "Airworthiness Limitations," Chapter 05, "Time Limits/Maintenance Checks," Gulfstream GVII-G500 Aircraft Maintenance Manual (AMM), Revision 18, dated March 29, 2024; and Section 05-10-10, "Airworthiness Limitations," Chapter 05, "Time Limits/Maintenance Checks," Gulfstream GVII-G600 AMM, Revision 14, dated March 29, 2024; as applicable. The initial compliance time for doing the tasks is at the time specified in Section 05-10-10, "Airworthiness Limitations," Chapter 05, "Time Limits/Maintenance Checks," Gulfstream GVII-G500 AMM, Revision 18, dated March 29, 2024; and Section 05-10-10, "Airworthiness Limitations," Chapter 05, "Time Limits/Maintenance Checks," Gulfstream GVII-G600 AMM, Revision 14, dated March 29, 2024; as applicable, or within 30 days after the effective date of this AD, whichever occurs later. Using a later revision of Section 05-10-10 of the applicable AMM with information identical to that contained in Section 05-10-10, "Airworthiness Limitations," Chapter 05, "Time Limits/Maintenance Checks," Gulfstream GVII-G500 AMM, Revision 18, dated March 29, 2024; and Section 05-10-10, "Airworthiness Limitations," Chapter 05, "Time Limits/Maintenance Checks," Gulfstream GVII-G600 AMM, Revision 14, dated March 29, 2024; as applicable, is acceptable for compliance with the requirements of this paragraph. (h) No Alternative Actions or Intervals After the existing maintenance or inspection program has been revised as required by paragraph (g) of this AD, no alternative actions ( e.g., inspections) or intervals may be used unless the actions and intervals are approved as an alternative method of compliance (AMOC) in accordance with the procedures specified in paragraph (j) of this AD. (i) Special Flight Permits Special flight permits, as described in 14 CFR 21.197 and 21.199, are not allowed. (j) Alternative Methods of Compliance (AMOCs) 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 East Certification Branch, send it to the attention of the person identified in paragraph (k) of this AD. Information may be emailed to: AMOC@faa.gov. Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the responsible Flight Standards Office. (k) Additional Information For more information about this AD, contact Jeffrey Johnson, Aviation Safety Engineer, FAA, 1701 Columbia Avenue, College Park, GA 30337; phone: 404-474-5554; email: ecb-cos@faa.gov. (l) 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) Section 05-10-10, "Airworthiness Limitations," Chapter 05, "Time Limits/Maintenance Checks," Gulfstream GVII-G500 Aircraft Maintenance Manual (AMM), Revision 18, dated March 29, 2024. (ii) Section 05-10-10, "Airworthiness Limitations," Chapter 05, "Time Limits/Maintenance Checks," Gulfstream GVII-G600 AMM, Revision 14, dated March 29, 2024. (3) For Gulfstream 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 pubs@gulfstream.com; 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 fr.inspection@nara.gov. Issued on January 14, 2026. Christopher R. Parker, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.