Summary
This document proposes the supersedure of an existing airworthiness directive (AD) that applies to specified type-certificated military surplus helicopters. That AD currently requires visual and radiographic inspections of the Boom Station (BS) 194 skin joint area and the vertical fin spar caps for cracks or fretting. This action would require those same actions, but would update the type certificate holder names and add additional model helicopters to the applicability. This proposal is prompted by the need to update the current type certificate holders and to expand the applicability to additional military surplus helicopters, and expand the inspection to include corrosion and loose or working rivets. The actions specified by the proposed AD are intended to detect a crack in the skin of a tailboom assembly, tail rotor gearbox support fitting, or vertical fin spar, which could cause failure of the tailboom and loss of control of the helicopter.