Airworthiness Directives; Fokker Model F.28 Mark 1000, 2000, 3000, and 4000 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to all Fokker Model F.28 Mark 1000, 2000, 3000, and 4000 series airplanes, that requires repetitive inspections to detect any discrepancy in the sealwire of the fireguards of the engine fire shut- off system, and repair, if necessary. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent inadvertent closure of the fire shut-off valves due to ineffective or absent sealwires, which could result in in-flight engine shutdown.