Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Gates Learjet Model 35 and 36 series airplanes that have been modified in accordance with Raisbeck Supplemental Type Certificate (STC) SA766NW. This proposal would require a reduction of the maximum operating limit speed on the affected airplanes to prevent encountering certain potentially hazardous conditions. This proposal is prompted by reports of incidents of aileron buffet or buzz experienced during high speed cruise. The actions specified by the proposed AD are intended to prevent aileron buffet or buzz conditions, which can result in the deterioration of the aircraft lateral control system characteristics to an unacceptable level.