Airworthiness Directives; Fokker Model F28 Mark 0100 and Mark 0070 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Fokker Model F28 Mark 0100 and Mark 0070 series airplanes, that requires modification of the hook and latch engagement assemblies of the engine cowl doors, measurement of the aerodynamic mismatch between the fixed cowl and lower cowl door, and repair, if necessary. This amendment is prompted by reports of operational experience that indicate that an aerodynamic mismatch may exist between the fixed engine cowl and the lower cowl door, and may be the result of one or more hooks of the engagement assemblies not engaging adequately. This condition may cause the other hooks to carry loads higher than they were originally designed to carry, and could result in the failure of those hooks that are engaged. The actions specified by this AD are intended to prevent possible separation of the lower cowling from the airplane due to failure of the hooks of the engagement assemblies.