Airworthiness Directives; Boeing Model 737-200 and -300 Series Airplanes Equipped With a Main Deck Cargo Door Installed in Accordance With Supplemental Type Certificate (STC) SA2969SO

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 737-200 and -300 series airplanes, that currently requires a one-time inspection to detect cracks of the lower frames and reinforcing angles of the main deck cargo door where the door latch fittings attach between certain fuselage stations and water lines, and replacement of any cracked part with a new part having the same part number. This amendment continues to require the existing actions and corrects a reference to an incorrect fuselage station. The actions specified by the AD are intended to detect and correct cracking of the lower portion of the main deck cargo door frames, which could result in sudden depressurization, loss or opening of the main deck cargo door during flight, and loss of control of the airplane.