2021-26-08
FR doc 2021-27645AD 2021-26-08Published 2021-12-23Effective 2022-01-27
Superseded by 2022-20-04
Supersedence is read from the Federal Register text of the newer AD — the FAA publishes no structured field for it — and names only ADs held in our index.
Requires removing certain nuts from service, installing newly designed nuts, and applying a specific torque and a torque stripe to each newly installed nut.
Full official abstract
The FAA is adopting a new airworthiness directive (AD) for certain Bell Textron Canada Limited Model 206, 206A, 206A-1, 206B, 206B-1, 206L, 206L-1, 206L-3, and 206L-4 helicopters. This AD was prompted by reports of cracked or missing nuts on the tail rotor drive shaft (TRDS) disc pack (Thomas) couplings. This AD requires removing certain nuts from service, installing newly designed nuts, and applying a specific torque and a torque stripe to each newly installed nut. This AD then requires, after the installation of each newly designed nut, inspecting the torque and, depending on the inspection results, either applying a torque stripe or performing further inspections and removing certain parts from service. Finally, this AD prohibits installing any affected nut on any TRDS Thomas coupling. The FAA is issuing this AD to address the unsafe condition on these products.