SUPPLEMENTARY INFORMATION:

Background

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain AHD Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, EC135T3, EC635T2+, MBB-BK 117 C-2, and MBB-BK 117 D-2 helicopters. The NPRM was published in the Federal Register on February 13, 2026 (91 FR 6795). The NPRM was prompted by an MCAI, issued by EASA, which is the Technical Agent for the Member States of the European Union. EASA issued EASA AD 2025-0055, dated March 11, 2025 (EASA AD 2025-0055) (also referred to as the MCAI). The MCAI states that cracks were reported on a cable drum installed on certain part-numbered Goodrich rescue hoist assemblies. Additionally, the material referenced in the MCAI states that Goodrich determined that this occurrence was isolated to a batch of cable drums made from a plate material, which was determined to have increased susceptibility to corrosion-induced fatigue. This unsafe condition, if not addressed, could result in corrosion-induced fatigue of the cable drum, and consequent injuries to human load or individuals on the ground.

In the NPRM, the FAA proposed to require repetitively inspecting the cable drum of certain rescue hoist assemblies for cracks and depending on the results, replacing or repairing the cable drum of the rescue hoist assembly. Additionally, in the NPRM the FAA proposed to prohibit the operation and the installation of an affected rescue hoist assembly on a helicopter, unless certain requirements are met. The FAA is issuing this AD to address the unsafe condition on these products.

Additionally, since the FAA issued the NPRM, it was determined that the special flight permit restriction specified in paragraph (j) of the proposed rule is no longer needed. Accordingly, the FAA has revised this final rule by removing the special flight permit paragraph.

Discussion of Final Airworthiness Directive

Comments

The FAA received comments from three commenters. The commenters were AHD, Onboard Systems Hoist and Winch, and an individual commenter. The following discussion presents the comments received on the NPRM and the FAA's response to these comments.

Request To Clarify Affected Parts

An individual commenter requested that the FAA specify the affected part by serial number, part number, and manufacturing batches that have the highest risk. The commenter also stated that by including this information, it will avoid unnecessary repeated inspections which may delay rescue missions.

The FAA disagrees with specifying or limiting this final rule by adding the serial number, part number, or manufacturing batch information. The AD already incorporates this information by reference, and the serial numbers associated with a subset of the affected part numbers are identified in the incorporated MCAI. Additionally, manufacturing batch information is not necessary to determine the affected parts, and all of the identified part numbers present an equivalent level of risk; none represent a “highest risk” category as suggested by the commenter. The FAA did not change this AD as a result of this comment. ( printed page 67458)

Request To Revise Inspection Requirements

One individual commenter requested that the FAA clarify why only visual inspections are required and not other forms of testing or inspections. The commenter stated that visual inspections may not detect small, undetectable cracks that are caused by corrosion, which may grow faster than expected. The commenter further stated that by including this information, it will help determine how often inspections must occur to ensure safe cable drums.

The FAA infers the commenter is requesting the inspection methods increase to other forms of inspections and not just visual inspections alone. The FAA disagrees with revising the inspection method outside of the requirements that were proposed in the NPRM. EASA, the State of Design authority for these helicopters, determined the appropriate inspection methodology and criteria for the required inspections. The FAA agrees with EASA. The FAA did not change this AD as a result of this comment.

Request To Revise the Inspection Requirements

AHD and Onboard Systems Hoist and Winch (Onboard Systems) both requested that the FAA revise or remove the inspection requirements of paragraphs (h)(3) and (4) of the proposed AD.

Onboard Systems requested the FAA revise paragraph (h)(3) of the proposed AD by allowing maintenance personnel a limited compliance time to confirm indications of a crack with personnel at Airbus Helicopters or Onboard Systems Hoist and Winch prior to repairs. Onboard Systems stated the inspection process was carefully considered to ensure that cracks are detected well before they pose any risk of fracture, while also preventing the removal of essential search and rescue assets from service for misidentified indications. Additionally, Onboard Systems stated that they would have the operator send detailed images of the indication and if the indication could not be identified as benign, then they would require removing the part from the helicopter. AHD stated the proposed inspection as specified in paragraph (h)(3) of the proposed AD implies further changes to the inspection process, which could eliminate the 3mm minimum crack size criteria.

The FAA disagrees with Onboard System request to revise the compliance time to confirm indications because the FAA may prioritize immediate action upon detection of potential safety concerns, such as cracks, to eliminate any risk of fracture that could compromise safety. However, the FAA agrees to revise paragraph (h)(3) of this AD by removing the criteria for contacting the Manager, International Validation Branch, or Airbus Helicopters' Design Organizational Approval if any cracks or suspected cracks longer than 3mm in length are found.

Onboard Systems requested the FAA remove paragraph (h)(4) of the proposed AD. Onboard Systems stated if using more than 6X magnification and no minimum threshold, the risk of false indications increases exponentially. AHD requested the FAA remove paragraph (h)(4) of the proposed AD or revise by removing the words “or higher.” AHD stated the use of such high magnification could increase misidentifications or surface cracks, leading to false-positive indications. AHD stated this inspection deviations could lead to false-positive indications and the unnecessary grounding of search and rescue assets.

The FAA acknowledges the commenter's concern to prevent unnecessary actions that may remove important resources essential to rescue missions and the FAA has determined that a crack length of 3 mm is too small to accurately detect with the unaided eye (1x magnification). However, the FAA agrees that a 4X-6X magnification is sufficient. Accordingly, the FAA has revised paragraph (h)(4) of this AD to specify that 4X-6X magnification is required for the visual inspection.

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, 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 EASA AD 2025-0055, which specifies procedures for repetitively inspecting the cable drum installed on the rescue hoist assembly for cracks longer than 3 mm and, depending on the results, contacting the manufacturer for approved repair instructions. Additionally, the MCAI allows the installation of an affected rescue hoist assembly on a helicopter if it meets certain requirements. Finally, the MCAI prohibits the operation of an affected rescue hoist assembly after a certain effective date as specified in the MCAI.

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 AHD 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.

Where the MCAI specifies to contact the manufacturer for repair instructions, this AD requires repairing an affected rescue hoist assembly in accordance with a method approved by the Manager, International Validation Branch; EASA; or Airbus Helicopters' Design Organization Approval.

Costs of Compliance

The FAA estimates that this AD affects 476 helicopters of U.S. registry.

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

The FAA estimates the following costs to do any replacements that would be required based on the results of the required inspection. The agency has no way of determining the number of helicopters that might need this replacement:

The FAA has no way of determining the cost to repair a rescue hoist assembly or the number of helicopters that may require either repair or replacement of the rescue hoist assembly if any cracks are found in the cable drum that are of a certain length or more.

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.

The Amendment

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