Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9 and DC-9-80 series airplanes, Model MD-88 airplanes, and C-9 (Military) airplanes, that currently requires repetitive inspections to detect fatigue cracking in the area of the attach tees of the ventral aft pressure bulkhead. That AD was prompted by reports of fatigue cracking found in that area. This proposed action would require revised inspection and repair procedures, and would provide for terminating action. It would also delete certain airplanes from the applicability of the rule. The actions specified by the proposed AD are intended to prevent the propagation of fatigue cracking, which could lead to structural failure of the ventral aft pressure bulkhead and subsequent rapid depressurization of the airplane.