Airworthiness Directives; British Aerospace (Jetstream) Model 4101 Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain British Aerospace (Jetstream) Model 4101 airplanes, that requires repetitive detailed visual inspections to detect cracking or other damage of certain diaphragm support structures of the forward equipment compartment; and repair, if necessary. This amendment is prompted by the issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to detect and correct failure of the two diaphragms that support the upper structure of the forward equipment compartment, which could accelerate fatigue damage in adjacent structure and result in reduced structural integrity of the airframe.