Airworthiness Directives; McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 Series Airplanes, and C-9 (Military) Airplanes

This amendment supersedes an existing airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 series airplanes and C-9 (military) airplanes, that currently requires a one-time visual inspection to determine if the doorstops and corners of the doorjamb of the forward passenger door have been modified, various follow-on repetitive inspections, and modification, if necessary. This amendment requires a reduction in the inspection threshold and repetitive intervals for a certain doubler configuration and an increase in the grace period for a certain other doubler configuration. This amendment is prompted by a determination that certain inspection compliance times were incorrect. The actions specified by this AD are intended to detect and correct fatigue cracking, which could result in rapid decompression of the fuselage and consequent reduced structural integrity of the airplane.