Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 757 series airplanes. This proposal would require replacement of transmission assemblies for the trailing edge flaps with modified transmission assemblies. This proposal is prompted by reports of broken bolts that attach the transmission assemblies for the trailing edge flaps. The actions specified by the proposed AD are intended to prevent damage to the flap system, adjacent system, or structural components; and excessive skew of the trailing edge flap; which could result in reduced controllability of the airplane.