Airworthiness Directives; Boeing Model 737, 747, 757, and 767 Series Airplanes

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 737, 747, 757, and 767 series airplanes. This action requires a one-time operational test of the pilots' seat locks and the seat tracks to ensure that the seats lock in position and the seat tracks are aligned correctly; and re-alignment of the seat tracks, if necessary. This amendment is prompted by reports indicating that a pilot's seat slid from the forward position to the aft-most position during acceleration and take-off of the airplane due to misalignment of the seat tracks. The actions specified in this AD are intended to prevent uncommanded movement of the pilots' seats during acceleration and take-off of the airplane, and consequent reduced controllability of the airplane.