Airworthiness Directives; Boeing Model 747 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747 series airplanes, that requires repetitive inspections to detect broken fasteners and cracking of the forward edge frame for main entry door number 3, and repair, if necessary. This amendment is prompted by reports of fatigue cracks at the inner chord and web of the body station 1265 edge frame between stringers 23 and 27. The actions specified by this AD are intended to detect and correct such cracking, which could result in rapid depressurization of the airplane.