Airworthiness Directives; Learjet Model 45 Airplanes

This document publishes in the Federal Register an amendment adopting airworthiness directive (AD) 2003-06-51 that was sent previously to all known U.S. owners and operators of certain Learjet Model 45 airplanes by individual notices. This AD requires an inspection to determine the part number of the horizontal stabilizer actuator assembly (A66), and replacement of any suspect horizontal stabilizer actuator assembly (A66) with a new or serviceable actuator assembly (A66). This action is prompted by a report of severe vibration followed by a rapid nose down pitch change on a Learjet Model 45 airplane. The actions specified by this AD are intended to prevent structural failure of the horizontal stabilizer actuator assembly, which could result in possible loss of control of the airplane.