Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 757 and 767 series airplanes. This proposal would require replacement of the thrust management computer (TMC) with a new TMC. This proposal is prompted by reports that, due to a defective relay within the TMC, an uncommanded advancement of the throttle levers occurred. The actions specified by the proposed AD are intended to prevent an uncommanded runaway of the autothrottle during flight or ground operations, which could distract the crew from normal operation of the airplane or lead to an unintended speed or altitude change.