Airworthiness Directives; Gulfstream Aerospace LP Airplanes

DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2025-5404; Project Identifier MCAI-2025-00424-T] RIN 2120-AA64 Airworthiness Directives; Gulfstream Aerospace LP Airplanes AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Gulfstream Aerospace LP (GALP) Model Gulfstream G280 airplanes. This proposed AD was prompted by reports of the accumulation of water in electrical connectors located in the aft fuselage directly below the empennage, resulting in empennage flight control related crew alerting system (CAS) messages. This proposed AD would require retrofitting the flight controls empennage electrical harness. The FAA is proposing this AD to address the unsafe condition on these products.

DATES:

The FAA must receive comments on this proposed AD by February 23, 2026.

ADDRESSES:

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:

• Federal eRulemaking Portal: Go to regulations.gov. Follow the instructions for submitting comments.

• Fax: 202-493-2251.

• 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.

• 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-2025-5404; 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 NPRM, the mandatory continuing airworthiness information (MCAI), any comments received, and other information. The street address for Docket Operations is listed above

der the ADDRESSES section. Include “Docket No. FAA-2025-5404; Project Identifier MCAI-2025-00424-T” at the beginning of your comments. The most helpful comments reference a specific portion of the proposal, 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 proposal 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 NPRM.

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 NPRM 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 NPRM, 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 NPRM. Submissions containing CBI should be sent to Richard Bolden, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 404-474-5592; email richard.bolden@faa.gov. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking

A, and they will not be placed in the public docket of this NPRM. Submissions containing CBI should be sent to Richard Bolden, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 404-474-5592; email richard.bolden@faa.gov. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking.

Background

The CAAI, which is the aviation authority for Israel, has issued CAAI AD ISR I-27-2025-03-06 R1, dated August 28, 2025 (CAAI AD ISR I-27-2025-03-06 R1) (also referred to as the MCAI), to correct an unsafe condition for certain GALP Model G280 airplanes. The MCAI states that several reports of empennage flight control related CAS messages have been attributed to the accumulation of water in electrical connectors located in the aft fuselage directly below the empennage. The unsafe condition, if not addressed, could, in combination with various specific failures or scenarios, result in loss of controllability of the airplane.

The FAA is proposing this AD to address the unsafe condition on these products.

You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2025-5404.

Material Incorporated by Reference Under 1 CFR Part 51

CAAI AD ISR I-27-2025-03-06 R1 specifies procedures for retrofitting the flight controls empennage electrical harness by replacing the backshells of electrical connectors at the vertical tail compartment.

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.

FAA's Determination

These products have been approved by the civil aviation authority of another country and are approved for operation in the United States. Pursuant to the FAA's bilateral agreement with this State of Design Authority, that authority has notified the FAA of the unsafe condition described in the MCAI referenced above

ry and are approved for operation in the United States. Pursuant to the FAA's bilateral agreement with this State of Design Authority, that authority has notified the FAA of the unsafe condition described in the MCAI referenced above. The FAA is issuing this NPRM after determining that the unsafe condition described previously is likely to exist or develop in other products of the same type design.

Proposed AD Requirements in This NPRM

This proposed AD would require accomplishing the actions specified in CAAI AD ISR I-27-2025-03-06 R1 described previously, except for any differences identified as exceptions in the regulatory text of this proposed AD.

Explanation of Required Compliance Information

In the FAA's ongoing efforts to improve the efficiency of the AD process, the FAA developed a process to use some civil aviation authority (CAA) ADs as the primary source of information for compliance with requirements for corresponding FAA ADs. The FAA has been coordinating this process with manufacturers and CAAs. As a result, the FAA proposes to incorporate CAAI AD ISR I-27-2025-03-06 R1 by reference in the FAA final rule. This proposed AD would, therefore, require compliance with CAAI AD ISR I-27-2025-03-06 R1 in its entirety through that incorporation, except for any differences identified as exceptions in the regulatory text of this proposed AD. Material required by CAAI AD ISR I-27-2025-03-06 R1 for compliance will be available at regulations.gov under Docket No. FAA-2025-5404 after the FAA final rule is published.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 140 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD:

Estimated Costs for Required Actions Labor cost Parts cost Cost per product Cost on U.S. operators 80 work-hours × $85 per hour = $6,800 $3,200 $10,000 $1,400,000 The FAA has included all known costs in its cost estimate

tial 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 this proposed regulation:

(1) Is not a “significant regulatory action” under Executive Order 12866,

(2) Would not affect intrastate aviation in Alaska, and

(3) Would 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 Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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:

Gulfstream Aerospace LP: Docket No. FAA-2025-5404; Project Identifier MCAI-2025-00424-T. (a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by February 23, 2026.

(b) Affected ADs

None.

(c) Applicability

This AD applies to Gulfstream Aerospace LP Model Gulfstream G280 airplanes, certificated in any category, as identified in Civil Aviation Authority of Israel (CAAI) AD ISR I-27-2025-03-06 R1, dated August 28, 2025 (CAAI AD ISR I-27-2025-03-06 R1).

(d) Subject

Air Transport Association (ATA) of America Code 27, Flight Controls.

ebruary 23, 2026.

(b) Affected ADs

None.

(c) Applicability

This AD applies to Gulfstream Aerospace LP Model Gulfstream G280 airplanes, certificated in any category, as identified in Civil Aviation Authority of Israel (CAAI) AD ISR I-27-2025-03-06 R1, dated August 28, 2025 (CAAI AD ISR I-27-2025-03-06 R1).

(d) Subject

Air Transport Association (ATA) of America Code 27, Flight Controls.

(e) Unsafe Condition

This AD was prompted by reports of the accumulation of water in electrical connectors located in the aft fuselage directly below the empennage, resulting in empennage flight control related crew alerting system (CAS) messages. The FAA is issuing this AD to address the accumulation of water in electrical connectors located in the aft fuselage directly below the empennage. The unsafe condition, if not addressed, could, in combination with various specific failures or scenarios, result in loss of controllability of the airplane.

(f) Compliance

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

(g) Requirements

Except as specified in paragraphs (h) and (i) of this AD: Comply with all required actions and compliance times specified in, and in accordance with, CAAI AD ISR I-27-2025-03-06 R1.

(h) Exceptions to CAAI AD ISR I-27-2025-03-06 R1

Where CAAI AD ISR I-27-2025-03-06 R1 refers to its effective date, this AD requires using the effective date of this AD.

(i) No Reporting Requirement

Although the material referenced in CAAI AD ISR I-27-2025-03-06 R1 specifies to submit certain information to the manufacturer, this AD does not include that requirement.

nternational Validation Branch, FAA; or CAAI; or CAAI's authorized Designee. If approved by the CAAI Designee, the approval must include the Designee's authorized signature.

(k) Additional Information

For more information about this AD, contact Richard Bolden, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: 404-474-5592; email: richard.bolden@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 this AD specifies otherwise.

(i) Civil Aviation Authority of Israel (CAAI) AD ISR I-27-2025-03-06 R1, dated August 28, 2025.

(ii) [Reserved]

(3) For CAAI material identified in this AD, contact CAAI, P.O. Box 1101, Golan Street, Airport City, 70100, Israel; telephone 972-3-9774665; fax 972-3-9774592; email aip@mot.gov.il. You may find this material on the CAAI website at www.gov.il/en/pages/israeli-airworthiness-directives.

(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 2, 2026. Christopher R. Parker, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.

[FR Doc. 2026-00119 Filed 1-6-26; 8:45 am] BILLING CODE 4910-13-P