Airworthiness Directives; Airbus Helicopters

DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2025-1736; Project Identifier MCAI-2024-00435-R]</DEPDOC> <RIN>RIN 2120-AA64</RIN> <SUBJECT>Airworthiness Directives; Airbus Helicopters</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Federal Aviation Administration (FAA), DOT. <HD SOURCE="HED">ACTION:</HD> Notice of proposed rulemaking (NPRM). <SUM> <HD SOURCE="HED">SUMMARY:</HD> The FAA proposes to supersede Airworthiness Directive (AD) 2020-06-12, which applies to certain Airbus Helicopters Model AS 332L2 and EC 225LP helicopters. AD 2020-06-12 requires determining the accumulated hours time-in-service (TIS) of certain part-numbered main gearbox (MGB) suspension bar attachment bolts (bolt) and certain part-numbered MGB suspension bar attachment fittings (fitting), applying a life limit add-on factor, and inspecting the torque of certain MGB suspension bar attachment nuts (nuts). Since the FAA issued AD 2020-06-12, the manufacturer developed a design improvement, and the FAA determined modifying the helicopter is necessary. This proposed AD would retain the actions required by AD 2020-06-12 and would also require modification of the MGB suspension bar, inspection of the torque, and corrective actions. This proposed AD would also allow credit for the initial service life calculations if certain requirements are met and would prohibit installing a certain bolt after the modification is accomplished on any helicopter. The FAA is proposing this AD to address the unsafe condition on these products. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> The FAA must receive comments on this NPRM by October 3, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods: • <E T="03">Federal eRulemaking Portal:</E> Go to <E T="03">regulations.gov.</E> Follow the instructions for submitting comments. • <E T="03">Fax:</E> (202) 493-2251. • <E T="03">Mail:</E> U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590. • <E T="03">Hand Delivery:</E> Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. <E T="03">AD Docket:</E> You may examine the AD docket at <E T="03">regulations.gov</E> under Docket No. FAA-2025-1736; 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. <E T="03">Material Incorporated by Reference:</E> • For Airbus Helicopters material identified in this proposed AD, contact Airbus Helicopters, 2701 North Forum Drive, Grand Prairie, TX 75052; phone: (972) 641-0000 or (800) 232-0323; fax: (972) 641-3775; website: <E T="03">airbus.com/en/products-services/helicopters/hcare-services/airbusworld.</E> It is also available at <E T="03">regulations.gov</E> under Docket No. FAA-2025-1736. • You may view this material at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Parkway, Room 6N-321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222-5110. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Dan McCully, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (781) 238-7244; email: <E T="03">william.mccully@faa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED"> SUPPLEMENTARY INFORMATION: </HD> <HD SOURCE="HD1">Comments Invited</HD> The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the <E T="02">ADDRESSES</E> section. Include “Docket No. FAA-2025-1736; Project Identifier MCAI-2024-00435-R” 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 the 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 <E T="03">regulations.gov</E> , including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this NPRM. <HD SOURCE="HD1">Confidential Business Information</HD> 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 Dan McCully, 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. <HD SOURCE="HD1">Background</HD> The FAA issued AD 2020-06-12, Amendment 39-19881 (85 FR 19077, April 6, 2020) (AD 2020-06-12), for Airbus Helicopters Model AS 332L2 and EC 225LP helicopters with a MGB suspension bar front bolt part number (P/N) 332A22-1613-21 or 332A22-1613-20, MGB suspension bar rear bolt P/N 332A22-1614-20, MGB suspension bar front fitting P/N 332A22-1623-01, MGB suspension bar rear left-hand fitting P/N 332A22-1624-02 or 332A22-1624-04, or MGB suspension bar rear right-hand fitting P/N 332A22-1624-03 or 332A22-1624-05 installed. AD 2020-06-12 was prompted by MCAI originated by the European Union Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union. EASA issued AD 2017-0189, dated September 22, 2017 (EASA AD 2017-0189), after finding the installation of the MGB upper deck fittings of the three MGB suspension bars could lead to tightening torque loss on the fittings' attachment bolts. EASA determined the life limits in the Airworthiness Limitations Sections for the bolts and fittings are valid if an “add-on penalty factor” is applied. AD 2020-06-12 requires determining the accumulated hours TIS of the affected bolts and fittings, applying a life limit add-on factor, and inspecting the torque of the MGB suspension bar attachment nuts. The FAA issued AD 2020-06-12 to address MGB suspension bar bolts and fittings remaining in service beyond their fatigue life and loose MGB suspension bar bolts and fittings, which could result in structural failure of the MGB suspension bar and loss of helicopter control. <HD SOURCE="HD1">Actions Since AD 2020-06-12 Was Issued</HD> Since the FAA issued AD 2020-06-12, EASA issued a series of ADs related to this unsafe condition. EASA AD 2022-0021, dated February 1, 2022 (EASA AD 2022-0021), superseded EASA AD 2017-0189 due to Airbus Helicopters developing a design improvement consisting of installing new links on the fittings of the MGB suspension bars through modifications 0728521, 0728904, 0728496 and 0729044. EASA AD 2022-0021 introduced new service life limits (SLL) for certain post-modification parts and a new tightening torque check. EASA AD 2022-0021 was subsequently superseded by EASA AD 2023-0147, dated July 19, 2023 (EASA AD 2023-0147), after EASA determined that, for helicopters modified with the new links on the fittings of the MGB suspension bars using earlier revisions of the service information, installing shims on the rear cooling rails of the MGB compartment was necessary. EASA revised AD 2023-0147 and issued EASA AD 2023-0147R1, dated March 12, 2025 (EASA AD 2023-0147R1) (also referred to as “the MCAI”) to address a difficulty with the installation of modification kits for EC 225LP helicopters. This condition, if not addressed, could lead to structural failure of the bolts or fittings, and consequent loss of control of the helicopter. You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2025-1736. <HD SOURCE="HD1">Material Incorporated by Reference Under 1 CFR Part 51</HD> The FAA reviewed Airbus Helicopters Emergency Alert Service Bulletin (EASB) No. 01.00.86, Revision 4, dated January 6, 2022 (EASB 01.00.86 Rev 4), for Model AS 332L2 helicopters and Airbus Helicopters EASB No. 04A013, Revision 4, dated January 6, 2022 (EASB 04A013 Rev 4), for Model EC 225LP helicopters. This material specifies procedures for applying an add-on factor to the flying hours logged by the pins (bolts) and fittings and replacing them if the SLL is exceeded. The FAA also reviewed Airbus Helicopters Alert Service Bulletin (ASB) No. AS332-53.02.03, Revision 2, dated June 15, 2023, for Model AS 332LP helicopters and Airbus Helicopters ASB No. EC225-53A065, Revision 4, dated May 28, 2024 (ASB EC225-53A065 Rev 4), for Model EC 225LP helicopters. This material specifies procedures to install new links on the attachment brackets of the MGB suspension bars and corresponds to Airbus Helicopters modification 0728496, 0728521, 0728904, and 0729044. This material is reasonably available because the interested p ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 35k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━