Airworthiness Directives; Fokker F28 Mark 1000, 2000, 3000, and 4000 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to all Fokker Model F28 Mark 1000, 2000, 3000, and 4000 series airplanes, that requires a one-time visual inspection of the rear cargo door and luggage auxiliary structure for corrosion, repetitive borescope inspections of the rear cargo door, and removal and repair of any corrosion found during the inspections. This amendment also requires the drilling of drain holes and application of a corrosion preventive and sealing compound inside the rear cargo door, and modification of the rear cargo door to aid in future routine borescope inspections. This amendment is prompted by reports of corrosion being found in the affected areas on several of the affected airplanes. The actions specified by this AD are intended to prevent such corrosion, which could result in structural failure of the cargo door and loss of the door during flight, and consequent rapid decompression, aerodynamic instability, and/or damage to other fuselage structures.