Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Fokker Model F.28 Mark 0070 and 0100 series airplanes. This proposal would require measurement of the over-center force of the thrust reverser operating levers; a functional test to verify proper energizing of the secondary lock solenoid of the thrust reversers; and corrective actions, if necessary. This action is necessary to detect and correct an insufficient over-center force in the corresponding thrust reverser operating lever, and incorrect setting of the thrust reverser selector switch (S9), which could result in uncommanded deployment of the thrust reversers during flight and consequent reduced controllability of the airplane. This action is intended to address the identified unsafe condition.