Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to all Fokker Model F.28 Mark 0070 and 0100 series airplanes, that currently requires Airplane Flight Manual (AFM) and maintenance program revisions, modifications, and repetitive checks associated with ensuring the integrity of the thrust reverser system. That AD was prompted by results of a review, which indicated that a potential latent failure of the secondary lock actuator switch 1 of the thrust reverser system in the open position may occur, in addition to the potential failure of the secondary lock relay 1 in the energized position. This proposed AD would continue to require the modifications and repetitive checks, and would add an AFM revision, repetitive operational tests, and other modifications related to the thrust reverser system. The new modifications would terminate the repetitive operational checks and tests. The actions specified by the proposed AD are intended to ensure protection against inadvertent deployment of the thrust reversers during flight, which could result in reduced controllability of the airplane.