Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Fokker Model F28 Mark 0100 series airplanes. For certain airplanes, this proposal would require an inspection to determine the torque value of the attaching parts of the interlock mechanism of the large cargo doors, and adjustment of the torque values that are outside certain limits. For certain other airplanes, the proposed AD would require removal of a spring from the interlock mechanism of the large cargo doors, and installation of a new microswitch bracket and two new springs in the interlock mechanism. This proposal is prompted by a report indicating that a spring on the interlock lever of the large cargo doors may become disconnected or the lever may become jammed in the ``activated'' state. The actions specified by the proposed AD are intended to prevent the spring from becoming disconnected or the lever from jamming. If other failures occur, the flightcrew could dispatch the airplane with improperly locked cargo doors; this condition could result in the opening and/or separation of the cargo doors while the airplane is in flight and subsequent rapid decompression and/or structural damage to the airplane.