Summary
This document proposes adopting a new airworthiness directive (AD) for Robinson Helicopter Company (RHC) Model R44 helicopters. The AD would require inspecting the pitch control assembly for roughness or binding of the pitch control bearings (bearings) by hand-rotating the pitch control bearing housing (housing). If the housing does not rotate freely, the proposed AD would require replacing the unairworthy pitch control assembly with an airworthy unit. This proposal is prompted by reports of failure of the tail rotor assembly due to improperly lubricated bearings on the RHC Model R22 and R44 helicopters. The actions specified by the proposed AD are intended to detect corrosion of the bearings and prevent bearing failure, breakup of the tail rotor assembly, tail rotor contact with the tailboom, and subsequent loss of control of the helicopter.