Airworthiness Directives; McDonnell Douglas Model DC-9 and DC-9- 80 Series Airplanes, and C-9 (Military) Series Airplanes

This amendment supersedes an existing airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9 and C-9 (military) series airplanes, that currently requires eddy current or dye penetrant inspection for cracks in the upper fuselage skin in the area of the aft pressure bulkhead tee. This amendment requires new improved repetitive inspections and follow-on actions, and expands the applicability of the existing AD to include additional airplanes. This amendment is prompted by additional reports of fatigue cracking and improperly seated attachments in the upper fuselage skin in the area of the aft pressure bulkhead tee. The actions specified in this 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.