Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 747 series airplanes. This proposal would require repetitive inspections to find cracking of the frame web, strap, inner chords, and inner chord angle of the forward edge frame of the number 5 main entry door cutout, and repair, if necessary. This action is necessary to find and fix such cracking, which could result in severing of the frame, inability of the edge frame to react door stop loads, and consequent rapid depressurization of the airplane. This action is intended to address the identified unsafe condition.