AD 99-17-17 64 FR 51200

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 99-17-17 which was sent previously to all known U.S. owners and operators of Robinson Helicopter Company (RHC) Model R44 helicopters by individual letters. This AD requires, prior to further flight, replacing certain yoke assemblies with airworthy yoke assemblies. This amendment is prompted by an incident in which, during cruise flight, the pilot heard a loud bang and no tail rotor effectiveness due to a cracked yoke assembly. RHC has identified the manufacturing lots associated with the failed yoke assembly. The actions specified by this AD are intended to prevent failure of the yoke assembly, which could result in loss of main and tail rotor drive and subsequent loss of control of the helicopter.