Document

Airworthiness Directives; Airbus Helicopters Deutschland GmbH (AHD) Helicopters

The FAA is adopting a new airworthiness directive (AD) for all Airbus Helicopters Deutschland GmbH (AHD) Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, E...

Department of Transportation
Federal Aviation Administration
  1. 14 CFR Part 39
  2. [Docket No. FAA-2026-11786; Project Identifier MCAI-2026-00439-R; Amendment 39-23479; AD 2026-20-06]
  3. RIN 2120-AA64
( printed page 61113)

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for all Airbus Helicopters Deutschland GmbH (AHD) Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, EC135T3, and EC635T2+ helicopters. This AD was prompted by a determination that in cases of loss of oil from the main gearbox (MGB), the low pressure caution or warning light might not activate. This AD requires revising the existing rotorcraft flight manual (RFM) for the helicopter by incorporating updated emergency, malfunction, and normal procedures. The FAA is issuing this AD to address the unsafe condition on these products.

DATES:

This AD is effective October 13, 2026.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of October 13, 2026.

The FAA must receive comments on this AD by November 12, 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-2026-11786; 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, the mandatory continuing airworthiness information (MCAI), any comments received, and other information. The street address for Docket Operations is listed above.

Material Incorporated by Reference:

  • For European Union Aviation Safety Agency (EASA) material identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email:; website: easa.europa.eu.
  • You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 10101 Hillwood Parkway, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222-5110. It is also available atregulations.gov under Docket No. FAA-2026-11786.

FOR FURTHER INFORMATION CONTACT:

Anthony Kenward, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (817) 222-5257; email: .

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to send any written data, views, or arguments about this final rule. Send your comments using a method listed under ADDRESSES . Include “Docket No. FAA-2026-11786; Project Identifier MCAI-2026-00439-R” 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 Anthony Kenward, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking.

Background

EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2026-0080, dated April 17, 2026 (EASA AD 2026-0080) (also referred to as the MCAI), to correct an unsafe condition on all AHD Model EC135 P1, EC135 P2, EC135 P2+, EC135 P3, EC135 T1, EC135 T2, EC135 T2+, EC135 T3, EC635 P2+, EC635 T1, and EC635 T2+ helicopters. The MCAI states a determination was made that in a case of loss of oil from the MGB, the low pressure caution or warning light might not activate. The FAA is issuing this AD to prevent undetected loss of oil from the MGB. The unsafe condition, if not addressed, could result in failure of the MGB and loss of control of the helicopter.

You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2026-11786. ( printed page 61114)

Material Incorporated by Reference Under 1 CFR Part 51

The FAA reviewed EASA AD 2026-0080, which specifies procedures for implementing the updated emergency, malfunction, and normal procedures. As an alternate to updating the procedures, EASA AD 2026-0080 specifies procedures for amending the existing RFM for the helicopter by inserting a copy of the applicable RFM temporary revision. 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 (CAA) 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. The FAA is issuing this AD after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design.

AD Requirements

This AD requires accomplishing the actions specified in EASA AD 2026-0080, described previously, as incorporated by reference, except for any differences identified as exceptions in the regulatory text of this AD. See “Differences Between this AD and the MCAI” for a discussion of the general differences included in this AD.

The owner/operator (pilot) holding at least a private pilot certificate may revise the existing RFM and must enter compliance into the helicopter maintenance records in accordance with 14 CFR 43.9(a) and 91.417(a)(2)(v). The pilot may perform this action because it only involves revising the RFM, which could be performed equally well by a pilot or mechanic. This is an exception to the FAA's standard maintenance regulations.

Differences Between This AD and the Referenced Material

The MCAI applies to AHD Model EC635 P2+ and EC635 T1, whereas this AD does not, because those models do not have an FAA type certificate.

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 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, EASA AD 2026-0080 is incorporated by reference in this AD. This AD requires compliance with EASA AD 2026-0080 in its entirety through that incorporation, except for any differences identified as exceptions in the regulatory text of this AD. Using common terms that are the same as the heading of a particular section in EASA AD 2026-0080 does not mean that operators need to comply only with that section. For example, where the AD requirement refers to “all required actions and compliance times,” compliance with this AD requirement is not limited to the section titled “Required Action(s) and Compliance Time(s)” in EASA AD 2026-0080. Material required by EASA AD 2026-0080 for compliance will be available at regulations.gov under Docket No. FAA-2026-11786 after this AD is published.

Justification for Immediate Adoption 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 requires the immediate adoption of this AD without providing an opportunity for public comments prior to adoption. The FAA has found that the risk to the flying public justifies forgoing notice and comment prior to adoption of this rule because the MGB is critical to the control of the helicopter, and without the low pressure caution or warning light being activated, the pilot would be unaware that the MGB was losing oil, which could cause the MGB to fail and lead to loss of control of the helicopter. Additionally, because failure of the MGB could occur during any phase of flight, the RFM procedures must be incorporated within 14 days or 50 hours time-in-service, whichever occurs first, after the effective date of this AD. These compliance times are shorter than the time necessary for the public to comment and for publication of the final rule. 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

The requirements of the Regulatory Flexibility Act (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 prior notice and comment, RFA analysis is not required.

Interim Action

The FAA considers that this AD is an interim action. If final actions are later identified, the FAA might consider further rulemaking.

Costs of Compliance

The FAA estimates that this AD affects 106 helicopters of U.S. registry.

The FAA estimates the following costs to comply with this AD:

Estimated Costs

Action Labor cost Parts cost Cost per product Cost on U.S. operators
Revise RFM 1 work-hour × $85 per hour = $85 $0 $85 $9,010
( printed page 61115)

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

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.

[Amended]

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

2026-20-06 Airbus Helicopters Deutschland GmbH (AHD): Amendment 39-23479; Docket No. FAA-2026-11786; Project Identifier MCAI-2026-00439-R.

(a) Effective Date

This airworthiness directive (AD) is effective October 13, 2026.

(b) Affected ADs

None.

(c) Applicability

This AD applies to all Airbus Helicopters Deutschland GmbH (AHD) Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, EC135T3, and EC635T2+ helicopters.

Note 1 to paragraph (c):

Helicopters with an EC135P3H designation are Model EC135P3 helicopters. Helicopters with an EC135T3H designation are Model EC135T3 helicopters.

(d) Subject

Joint Aircraft System Component (JASC) Code 6320, Main rotor gearbox.

(e) Unsafe Condition

This AD was prompted by a determination that in cases of loss of oil from the main gearbox (MGB), the low pressure caution or warning light might not activate. The FAA is issuing this AD to prevent undetected loss of oil from the MGB. The unsafe condition, if not addressed, could result in failure of the MGB and loss of control of the helicopter.

(f) Compliance

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

(g) Required Actions

(1) Except as specified in paragraph (h) of this AD: Comply with all required actions and compliance times specified in, and in accordance with European Union Aviation Safety Agency AD 2026-0080, dated April 17, 2026 (EASA AD 2026-0080).

(2) Insert the following language into the Normal section of the existing rotorcraft flight manual (RFM) for your helicopter: “WARNING: Pilots must vigilantly monitor the main gearbox oil pressures and temperatures. Main gearbox oil loss could occur without triggering cautions, warnings, or audio alerts. Catastrophic failure of the main gearbox could result in severe aircraft damage, injury, or death.”

(3) The owner/operator (pilot) holding at least a private pilot certificate may revise the existing RFM for the helicopter, as required by this AD, and must enter compliance into the helicopter maintenance records in accordance with 14 CFR 43.9(a) and 91.417(a)(2)(v). The record must be maintained as required by 14 CFR 91.417, 121.380, or 135.439.

(h) Exceptions to EASA AD 2026-0080

(1) Where EASA AD 2026-0080 refers to its effective date, this AD requires using the effective date of this AD.

(2) Where EASA AD 2026-0080 refers to flight hours, this AD requires using hours time-in-service.

(3) Where paragraph (1) of EASA AD 2026-0080 specifies “implement the updated procedures, as defined in this AD,” this AD requires replacing that text with “amend the existing RFM for the helicopter by inserting a copy of the RFM TR [temporary revision] specified in EASA AD 2026-0080”.

(4) This AD does not adopt paragraph (2) or the “Remarks” section of EASA AD 2026-0080.

(i) Alternative Methods of Compliance (AMOCs)

(1) The Manager, International Validation 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 local Flight Standards District Office, as appropriate. If sending information directly to the manager of the International Validation Branch, send it to the attention of the person identified in paragraph (j) of this AD and email to: .

(2) 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.

(j) Additional Information

For more information about this AD, contact Anthony Kenward, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (817) 222-5257; email: .

(k) 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) European Union Aviation Safety Agency (EASA) AD 2026-0080, dated April 17, 2026.

(ii) [Reserved]

(3) For EASA material identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email: ; website: easa.europa.eu.

(4) You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 10101 Hillwood Parkway, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222-5110.

(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 .

Issued on September 22, 2026.

Paul R. Bernado,

Director, Compliance & Airworthiness Division, Aircraft Certification Service.

[FR Doc. 2026-19757 Filed 9-25-26; 8:45 am]

BILLING CODE 4910-13-P

Legal Citation

Federal Register Citation

Use this for formal legal and research references to the published document.

91 FR 61113

Web Citation

Suggested Web Citation

Use this when citing the archival web version of the document.

“Airworthiness Directives; Airbus Helicopters Deutschland GmbH (AHD) Helicopters,” thefederalregister.org (September 28, 2026), https://thefederalregister.org/documents/2026-19757/airworthiness-directives-airbus-helicopters-deutschland-gmbh-ahd-helicopters.