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 document publishes in the Federal Register an amendment adopting airworthiness directive (AD) 2000-17-51 that was sent previously to all known U.S. owners and operators of certain Boeing Model 737-200 and -300 series airplanes by individual notices. This AD supersedes an existing AD to require 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 action is prompted by reports that, during the inspections required by the existing AD, cracks were found in the reinforcing angles of the main deck cargo door frame. The actions specified by this 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.