Airworthiness Directives: McDonnell Douglas Helicopter Company and Hughes Helicopters, Inc. Model 369 and OH-6A Series Helicopters

Streszczenie

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to McDonnell Douglas Helicopter Company and Hughes Helicopters, Inc. Model 369 and OH-6A series helicopters equipped with certain main rotor (M/R) blade assemblies or certain M/R hub lead-lag assemblies, that currently requires repetitive inspections and checks for cracks. This action would require the same inspections as the superseded AD, but would eliminate pilot checks, expand the areas of inspection, and require the application of slippage marks on each M/R blade root fitting lug and related bushings to detect movement. This proposal is prompted by additional reports of cracks in the M/R blade root fittings, lugs, and adjacent blade skin, and movement of the root fitting bushings. The actions specified by the proposed AD are intended to prevent failure of a M/R blade assembly or a M/R hub lead-lag link assembly, loss of a M/R blade, and subsequent loss of control of the helicopter.