AD 2024-20-04 Airworthiness Directives; Various Helicopters

This AD applies to all helicopters, certificated in any category, with a restraint system with a Pacific Scientific Company rotary buckle assembly (buckle) part number (P/N) 1111475 (all dash numbers) or P/N 1111548-01 having a date of manufacture (DOM) between January 2012 and April 2013 inclusive, or an unknown DOM. These buckles may be installed on, but not limited to, Airbus Helicopters model helicopters. Note 1 to paragraph (c): The buckle may be included as a component of a different part-numbered restraint system assembly. Note 2 to paragraph (c): These buckles may also be installed on airplanes; however, the FAA determined that a longer compliance time to accomplish the required actions is allowable for buckles installed on airplanes. Accordingly, the FAA plans to publish a separate AD rulemaking to address all airplanes with an affected buckle installed.

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

(1) For helicopters with buckle P/N 1111475 (all dash numbers), within 3 months after the effective date of this AD, inspect each buckle screw for cracked, loose, and missing screw heads by following the Accomplishment Instructions, paragraphs B.(1) and (2), of Parker Meggitt Service Bulletin (SB) 1111475-25-001-2023, Revision 002, dated April 1, 2024 (SB 1111475-25-001-2023 Rev 002). (i) If any screw has a cracked, loose, or missing screw head, before further flight, replace the buckle with an airworthy buckle. (ii) If none of the four screw heads are cracked, loose, or missing, before further flight, inspect each screw to determine if any screw has a Torx head by using one of the following methods in the Accomplishment Instructions of SB 1111475-25-001-2023 Rev 002: paragraph B.(4)(a) (Magnet Test); paragraph B.(4)(b) (Inspection); or paragraphs C.(2) through (4) (removing the buckle from the restraint system) and paragraphs D.(1)(a) through (d) (disassembling the buckle). (A) If none of the four screws have a Torx head, before further flight, reassemble the buckle (if necessary) by following the Accomplishment Instructions, paragraphs D.(1)(f) through (l), of SB 1111475-25-001-2023 Rev 002, and reidentify the buckle with “INS. A” by following the Accomplishment Instructions, paragraph B.(6), of SB 1111475-25-001-2023 Rev 002. (B) If at least one of the four screws has a Torx head, before further flight, with the buckle removed, replace each Torx head screw with a hex head screw, reassemble the buckle, and reidentify the buckle with “MOD. A” by following the Accomplishment Instructions, paragraphs D.(1)(e) through (m), of SB 1111475-25-001-2023 Rev 002, except you are not required to return any parts to Parker Meggitt. If a screw head breaks off during disassembly, before further flight, replace the buckle with an airworthy buckle. Note 3 to paragraph (g)(1): SB 1111475-25-001-2023 Rev 002 refers to a magnifying glass as an “eye loupe.” (2) For helicopters with buckle P/N 1111548-01, within 3 months after the effective date of this AD, inspect each buckle screw for cracked, loose, and missing screw heads by following the Accomplishment Instructions, paragraph B.(1), of Parker Meggitt SB 1111548-25-001-2023, Revision 002, dated April 1, 2024 (SB 1111548-25-001-2023 Rev 002). (i) If any screw has a cracked, loose, or missing screw head, before further flight, replace the buckle with an airworthy buckle. (ii) If none of the four screw heads are cracked, loose, or missing, before further flight, inspect each screw to determine which screws have a Torx head by using one of the following methods in the Accomplishment Instructions of SB 1111548-25-001-2023 Rev 002: paragraph B.(3)(a) (Inspection); or paragraph C. (removing the buckle from the restraint system) and paragraphs D.(1)(a) through (c) (disassembling the buckle). (A) If none of the four screws have a Torx head, before further flight, reassemble the buckle (if necessary) by following the Accomplishment Instructions, paragraphs D.(1)(e) through (l), of SB 1111548-25-001-2023 Rev 002, and reidentify the buckle with “INS. A” by following the Accomplishment Instructions, paragraph B.(5), of SB 1111548-25-001-2023 Rev 002. (B) If at least one of the four screws has a Torx head, before further flight, with the buckle removed, replace each Torx head screw with a hex head screw, reassemble the buckle, and reidentify the buckle with “MOD. A” by following the Accomplishment Instructions, paragraphs D.(1)(d) through (m), of SB 1111548-25-001-2023 Rev 002, except you are not required to return any parts to Parker Meggitt. If a screw head breaks off during disassembly, before further flight, replace the buckle with an airworthy buckle. Note 4 to paragraph (g)(2): SB 1111548-25-001-2023 Rev 002 refers to a magnifying glass as an “eye loupe.” (3) As of the effective date of this AD, do not install a buckle identified in paragraph (c) of this AD on any helicopter unless the buckle is marked with “MOD. A” or “INS. A.” (4) For a crewmember seat or passenger seat with a restraint system with a buckle identified in paragraph (c) of this AD installed, as an option for the actions required by paragraph (g)(1) or (2) of this AD, as applicable, within 3 months after the effective date of this AD: (i) Remove the male side from the lap of the restraint system assembly. (ii) Fabricate a placard using at least 1/8 inch letters with the words “USE OF THIS SEAT IS PROHIBITED” on it and install the placard on the seat within the crewmember or passenger's clear view. The seat is then inoperative until the actions required by paragraph (g)(1) or (2) of this AD, as applicable, are accomplished and the male side from the lap of the restraint system assembly is reinstalled.

This AD was prompted by a report of a manufacturing defect in the screws used inside the buckle. The FAA is issuing this AD to prevent cracking and missing screw heads when under load. The unsafe condition, if not addressed, could result in a failure of the buckle to restrain the occupant.

This AD replaces AD 2024-01-11, Amendment 39-22662 (89 FR 6008, January 31, 2024) (AD 2024-01-11).