Airworthiness Directives; Airbus Helicopters Deutschland GmbH (AHD) Helicopters
The FAA is superseding Airworthiness Directive (AD) 2024-04-10 which applied to all Airbus Helicopters Deutschland GmbH (AHD) Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1,...
[Docket No. FAA-2026-7230; Project Identifier MCAI-2026-00185-R; Amendment 39-23512; AD 2026-22-10]
RIN 2120-AA64
AGENCY:
Federal Aviation Administration (FAA), DOT.
ACTION:
Final rule.
SUMMARY:
The FAA is superseding Airworthiness Directive (AD) 2024-04-10 which applied to all Airbus Helicopters Deutschland GmbH (AHD) Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, EC135T3, and EC635T2+ helicopters. AD 2024-04-10 required repetitively inspecting certain part-numbered tail rotor (T/R) blades for a crack and, depending on the results, removing any cracked T/R blade from service. AD 2024-04-10 also prohibits installing certain T/R blades on any helicopter unless certain requirements are met. Since AD 2024-04-10 was issued, it was determined that inspection Method A should be discontinued and that additional limitations shall be provided. This AD retains the actions of AD 2024-04-10 and requires repetitively inspecting a certain tail rotor blade (TRB) assembly for cracks and, depending on the results, removing any cracked TRB assembly from service and replacing an affected part as terminating action for the repetitive inspections. This AD also prohibits installing an affected TRB assembly on any helicopter unless certain requirements are met. The FAA is issuing this AD to address the unsafe condition on these products.
DATES:
This AD is effective December 14, 2026.
The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of December 14, 2026.
ADDRESSES:
AD Docket:
You may examine the AD docket at
regulations.gov
under Docket No. FAA-2026-7230; 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 address for Docket Operations is U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.
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:ADs@easa.europa.eu;
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-2026-7230.
FOR FURTHER INFORMATION CONTACT:
Soban Saeed, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (316) 946-4123; email:
soban.saeed@faa.gov.
SUPPLEMENTARY INFORMATION:
( printed page 70772)
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2024-04-10, Amendment 39-22689 (89 FR 15431, March 4, 2024), (AD 2024-04-10). AD 2024-04-10 applied to all AHD Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, EC135T3, and EC635T2+ helicopters. AD 2024-04-10 required repetitively inspecting T/R blades having part number (P/N) L642A2002111 or P/N L642A2002112 installed for a crack and, depending on the results, removing any cracked T/R blade from service. AD 2024-04-10 also prohibited installing certain T/R blades on any helicopter unless certain requirements are met. The FAA issued AD 2024-04-10 to detect and address cracks in affected T/R blades. The unsafe condition, if not addressed, could result in separation of a T/R blade assembly and subsequently reduced control of the helicopter.
The NPRM was published in the
Federal Register
on July 30, 2026 (91 FR 47994). The NPRM was prompted by an MCAI originated by EASA, which is the Technical Agent for the Member States of the European Union. EASA issued EASA AD 2026-0032, dated February 19, 2026 (EASA AD 2026-0032) (also referred to as the MCAI). The MCAI states that a determination was made by the manufacturer that a previously approved inspection method (Method A) should be discontinued. Method A consisted of a dye-penetrant (with increased temperature) inspection.
In the NPRM, the FAA proposed to retain the requirements of AD 2024-04-10 and also proposed to require repetitively inspecting a certain TRB assembly for cracks and, depending on the results, removing any cracked TRB assembly from service and replacing an affected part as terminating action for the repetitive inspections. In the NPRM, the FAA also proposed to prohibit installing an affected TRB assembly on any helicopter unless certain requirements are met.
You may examine the MCAI in the AD docket at
regulations.gov
under Docket No. FAA-2026-7230.
Discussion of Final Airworthiness Directive
Comments
The FAA received no comments on the NPRM or on the determination of the costs.
Conclusion
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. 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, 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 EASA AD 2026-0032, which specifies procedures for repetitively inspecting the affected TRB assembly for cracks and, if any crack is detected, replacing the affected TRB assembly with a serviceable part. EASA AD 2026-0032 prohibits installing a certain TRB assembly on any helicopter unless certain requirements are met and specifies that replacing an affected TRB assembly with an eligible TRB assembly that is not an affected part is terminating action for certain repetitive inspections.
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.
Differences Between This AD and the MCAI
The MCAI applies to Airbus Helicopters Model EC635 P2+, EC635 P3, EC635 T1, and EC635 T3 helicopters, whereas this AD does not because those models do not have an FAA type certificate.
The MCAI specifies inspecting cracks by performing a visual inspection, dye-penetrant inspection, eddy current inspection, or fluorescent penetrant inspection, whereas this AD requires inspection methods under certain scenarios as outlined in the regulatory text of this AD, which are also described in a Note in the regulatory text of this AD.
Costs of Compliance
The FAA estimates that this AD affects 359 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
Inspect one affected TRB assembly (up to 10 per helicopter)
3 work-hours × $85 per hour = $255
$50
Up to $305
Up to $109,495.
The FAA estimates the following costs to do any replacements that will be required based on the results of the inspection. The agency has no way of determining the number of helicopters that might need this replacement:
On-Condition Costs
Action
Labor cost
Parts cost
Cost per product
Replace one TRB assembly (up to 10 per helicopter)
3 work-hours × $85 per hour = $255
$4,900 per TRB assembly
Up to $51,550.
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.
( printed page 70773)
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
The FAA has determined that 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:
(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.
This airworthiness directive (AD) is effective December 14, 2026.
(b) Affected ADs
This AD replaces AD 2024-04-10, Amendment 39-22689 (89 FR 15431, March 4, 2024) (AD 2024-04-10).
(c) Applicability
This AD applies to all Airbus Helicopters Deutschland GmbH (AHD) Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, EC135T3, and EC635T2+ helicopters, certificated in any category.
(d) Subject
Joint Aircraft System Component (JASC) Code 6410, Tail rotor blades.
(e) Unsafe Condition
This AD was prompted by a report of a separated tail rotor blade (TRB) assembly due to a crack in the TRB assembly caused by intergranular corrosion. The FAA is issuing this AD to detect and address cracks in the TRB assembly. The unsafe condition, if not addressed, could result in separation of a TRB assembly and reduced control of the helicopter.
(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, European Union Aviation Safety Agency AD 2026-0032, dated February 19, 2026 (EASA AD 2026-0032).
(h) Exceptions to EASA AD 2026-0032
(1) Where EASA AD 2026-0032 refers to its effective date, this AD requires using the effective date of this AD.
(2) Where EASA AD 2026-0032 refers to January 29, 2024 (the effective date of EASA Emergency AD 2024-0028-E), this AD requires using March 19, 2024 (the effective date of AD 2024-04-10).
(3) Where EASA AD 2026-0032 refers to flight hours, this AD requires using hours time-in-service (TIS).
(4) Where paragraph (1) of EASA AD 2026-0032 specifies “Before an affected part exceeds 685 FH [flight hours] since first installation on a helicopter”, this AD requires replacing that text with “Before an affected part accumulates 685 hours TIS since first installation on a helicopter, or within 10 hours TIS after March 19, 2024 (the effective date of AD 2024-04-10), whichever occurs later”.
(5) Where paragraph 4.3 of the material referenced in EASA AD 2026-0032 recommends type II visible dye inspections, this AD requires the inspection methods in paragraphs (h)(5)(i), (ii), or (iii) of this AD, as applicable:
(i) If the affected part has previously been inspected using a type II visible dye method, perform type II visible dye (Method B of the material referenced in EASA AD 2026-0032) or eddy current inspections, instead of fluorescent penetrant inspections.
(ii) If the affected part has not previously been inspected using a type II visible dye inspection, perform eddy current or fluorescent penetrant inspections, instead of type II visible dye inspections.
(iii) If you cannot determine whether the affected part has previously been inspected by a type II visible dye method, clean all surfaces to be inspected and perform an eddy current or a fluorescent penetrant inspection, instead of a type II visible dye inspection.
Note 1 to paragraph (h)(5):
The FAA reminds operators of the airworthiness concern regarding type II visible dye inspections of critical parts discussed in FAA Special Airworthiness Information Bulletin (SAIB) CE-18-26R1, dated October 30, 2018 (SAIB CE-18-26R1). SAIB CE-18-26R1 explains the risks associated with using type II visible dye inspection methods, including the prohibition in ASTM E1417 on the use of type II visible dye penetrant prior to the use of type I fluorescent penetrant on the same surface. SAIB CE-18-26R1 also advises of the importance of pre- and post-inspection cleaning to ensure proper detection of cracks. You can find SAIB CE-18-26R1 at
drs.faa.gov.
Note 2 to paragraph (h)(5):
The material referenced in EASA AD 2026-0032 identifies a type II visible dye inspection as Method A (not allowed) or Method B; eddy current inspection as Method C; fluorescent penetrant inspection as Method D; and visual inspection as Method E.
Note 3 to paragraph (h)(5):
When entering compliance with the applicable paragraph of the AD into the helicopter maintenance records, documenting that a type II visible dye inspection was performed improves the accuracy of maintenance records.
(6) This AD does not adopt paragraph (3) of EASA AD 2026-0032.
(7) This AD does not adopt the “Remarks” section of EASA AD 2026-0032.
(i) No Reporting or Returning of Parts
Where the material referenced in EASA AD 2026-0032 specifies to submit certain information and to send removed parts to the manufacturer, this AD does not include those actions.
(j) Special Flight Permits
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, 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 responsible 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 (l) of this AD and email to
AMOC@faa.gov.
(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager
( printed page 70774)
of the local flight standards district office/certificate holding district office.
(l) Additional Information
For more information about this AD, contact Soban Saeed, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (316) 946-4123; email:
soban.saeed@faa.gov.
(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) European Union Aviation Safety Agency (EASA) AD 2026-0032, dated February 19, 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:
ADs@easa.europa.eu;
website:
easa.europa.eu.
You may find the EASA material on the EASA website at
ad.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.
14 CFR part 39
49 U.S.C. 106(g)
www.archives.gov/federal-register/cfr/ibr-locations