Airworthiness Directives; MD Helicopters, Inc. Model 369A, D, E, H, HE, HM, HS, F, and FF Helicopters

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2003-08-51, which was sent previously to all known U.S. owners and operators of the specified model MD Helicopters, Inc. helicopters by individual letters. This AD requires reducing the retirement life of certain tail rotor blades, performing a one-time visual inspection of each tail rotor blade pitch horn (pitch horn) for a crack or corrosion, and replacing unairworthy tail rotor blades with airworthy tail rotor blades. This AD also requires revising the Airworthiness Limitations section of the helicopter maintenance manual to reflect the reduced retirement life, and reporting information to the FAA within 24 hours following the one- time inspection. The actions specified by this AD are intended to prevent a pitch horn from separating from the tail rotor blade, leading to an unbalanced condition, vibration, loss of tail rotor pitch control, and loss of directional control of the helicopter.