Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to all Fokker Model F.28 Mark 0070 and Mark 0100 series airplanes, that currently requires revising the Airplane Flight Manual (AFM) to provide the flightcrew with instructions not to arm the liftdumper system prior to commanding the landing gear to extend. For Model F.28 Mark 0100 series airplanes, the existing AD also requires modification of the grounds of the shielding of the wheelspeed sensor wiring of the main landing gear (MLG) and installation of new electrical grounds for the wheelspeed sensor channel of the anti-skid control box of the MLG. The proposed AD would remove the previous revision of the AFM and would require a new limitation and a new warning. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to prevent inadvertent deployment of the liftdumpers during approach for landing or reduced brake pressure during low speed taxiing, and consequent reduced controllability and performance of the airplane.