Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

摘要

We propose to adopt a new airworthiness directive (AD) for Sikorsky Aircraft Corporation (Sikorsky) Model S-92A helicopters, which requires inspecting the tail rotor (T/R) pylon for a loose or missing fastener, a crack, damage, or corrosion and adding an internal doubler to the aft shear deck tunnel assembly. This proposed AD is prompted by the discovery of cracks in T/R pylons. The proposed actions are intended to detect a loose or missing fastener, a crack, damage, or corrosion on the T/R pylon and, if present, to repair the T/R Pylon and install a doubler on the aft shear deck tunnel assembly or to replace the T/R pylon and install the doubler on the aft shear deck tunnel assembly to prevent failure of the T/R pylon or other T/R components, and subsequent loss of control of the helicopter.