FAA 2022-20-04

Supersedes AD 2021-26-08, which required removing certain nuts from service, installing newly designed nuts, applying a specific torque and a torque stripe to each newly installed nut,  and further inspections and replacements, if necessary. AD 2021-26-08 also prohibited installing any affected nut on any tail rotor drive shaft (TRDS) disc pack (Thomas) coupling. Since the FAA issued AD 2021-26-08, the FAA determined certain torque values and part numbers (P/Ns) need to be revised. This AD was prompted by reports of cracked or missing nuts installed on the TRDS Thomas couplings and the need to revise certain torque values and P/Ns in AD 2021-26-08. This AD requires removing certain nuts from service. installing newly designed nuts; applying torque and a torque stripe; and additional corrective actions if necessary. This AD also prohibits installing any affected nut on any TRDS Thomas coupling, as specified in a Transport Canada AD,