Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all Fokker Model F.28 Mark 1000, 2000, 3000, and 4000 series airplanes. This proposed AD would require a detailed inspection to determine the presence of incorrectly installed bushings in the attachment holes of the reinforcing strap of the left- and right-hand wings' lower skin, and corrective actions if necessary. This proposed AD is prompted by a report that bushings were installed in accordance with improper procedures in the structural repair manual. We are proposing this AD to detect and correct improperly installed bushings, which could result in reduced tensile strength of the reinforcing strap of the wing's lower skin, and consequently a reduction of the structural capability of the wing and possible wing failure.