Summary
This document proposes the adoption of a new airworthiness directive (AD), applicable to certain Dassault Model Falcon 900EX and Mystere Falcon 900 series airplanes. This action would require repetitive operational tests of the flap asymmetry detection system to verify proper functioning, and repair, if necessary; repetitive replacement of the inboard flap jackscrews on the inboard with new or reconditioned jackscrews; and repetitive measurement of the screw/nut play of the jackscrews on the inboard and outboard flaps to detect discrepancies, and corrective action, if necessary. This action would also require revision of the Airplane Flight Manual. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions proposed by this AD are intended to prevent jamming of the flap jackscrews during the approach to landing, which could result in inability to move the flaps or an asymmetric flap condition,and consequent reduced controllability of the airplane.