AD 2022-20-01 Prompted By Reports Of Excessively Worn Bolts...

The FAA is adopting a new airworthiness directive (AD) for all Airbus Helicopters Deutschland GmbH (AHD) Model MBB-BK 117 C-2 helicopters.

This AD was prompted by reports of excessively worn bolts that connect the cardan-pivot joint with the piston rod of the tail rotor actuator (TRA) assembly. This AD requires repetitively inspecting certain TRA assemblies, and depending on the results, replacing or repairing parts, or accomplishing additional inspections. This AD also prohibits installing an affected TRA assembly unless it passes required inspections. Lastly, this AD provides terminating actions for certain inspections, as specified in a European Union Aviation Safety Agency (EASA) AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective November 14, 2022.

Supplementary Information: EASA, which is the Technical Agent for the Member States of the European Union, has issued a series of EASA ADs, with the most recent being EASA AD 2022-0086, dated May 13, 2022 (EASA AD 2022-0086), to correct an unsafe condition for Airbus Helicopters Deutschland GmbH (AHD), formerly Eurocopter Deutschland GmbH; and Airbus Helicopters Inc., formerly American Eurocopter LLC, Model MBB-BK117 C-2 helicopters. EASA issued EASA AD 2022-0086 to supersede EASA AD 2019-0313, dated December 20, 2019.

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to all Airbus Helicopters Deutschland GmbH (AHD) Model MBB-BK 117 C-2 helicopters. The NPRM published in the Federal Register on July 14, 2022 (87 FR 42106). The NPRM was prompted by reports of excessively worn bolts that connect the cardan-pivot joint with the piston rod of the TRA assembly. According to Airbus Helicopters, manufacturer investigations of affected TRAs have revealed improperly assembled cardan-pivot joints as the main cause of the excessively worn bolts. Additionally, incorrect washers as well as improperly shimmed laminated washers contribute to axial play and increased wear of the bolt. The NPRM proposed to require repetitively inspecting certain TRA assemblies, and depending on the results, replacing or repairing parts, or accomplishing additional inspections. The NPRM also proposed to prohibit installing an affected TRA assembly unless it passed required inspections. Lastly, the NPRM proposed terminating actions for certain inspections, as specified in EASA AD 2022-0086.

FMI: www.regulations.gov