Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Boeing Model 727-200 series airplanes. This proposal would require repetitive inspections to detect cracks in certain areas between the upper and lower sills of the number 1 cargo door, and repair, if necessary. This proposal is prompted by reports indicating that fatigue cracks were found in certain structures adjacent to the number 1 cargo door cutout at the forward and aft doorway frames. The actions specified by the proposed AD are intended to detect and correct such fatigue cracking, which could result in rapid decompression of the fuselage and consequent reduced structural integrity of the airplane.