Airworthiness Directives; Boeing Model 707, 727C, and 727-100C Series Airplanes

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 707, 727C, and 727-100C series airplanes, that currently requires repetitive inspections to detect cracking of the main cargo door skin and frames, and repair, if necessary. The existing AD also provides optional terminating modifications. This amendment requires follow-on repetitive inspections of repaired or modified areas for certain airplanes. This amendment is prompted by reports of cracking and/or tearing of the main cargo door outer skin and subsequent failure of the door frame. The actions specified by this AD are intended to detect and correct such cracking and/or tearing, which could result in failure of the door frame and consequent rapid decompression of the airplane.