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 detect cracks in the edge frame web and doubler of the number 1 main entry door cutout; and repair, if necessary. This proposed AD also provides for optional terminating action for the repetitive inspections. This proposal is prompted by reports indicating that fatigue cracks were found in the edge frame web and doubler at the door stop number 1 of the number 1 main entry door cutout. The actions specified by the proposed AD are intended to detect and correct such fatigue cracking, which could result in rapid decompression of the airplane.