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

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 737-200 and -300 series airplanes. This action requires repetitive inspections to detect cracks in the hinge and lift actuator box area of the main deck cargo door and upper jamb of the fuselage; and repair or replacement of any cracked part with a new part having the same part number. This amendment is prompted by a report that, during a periodic heavy maintenance check, cracks were found in the upper jamb area of the fuselage and in the main deck cargo door. The actions specified in this AD are intended to detect and correct such cracking, which could result in reduced structural integrity of the main cargo door and/or fuselage, and consequent loss or opening of the main deck cargo door while the airplane is in flight, or reduced controllability of the airplane.