Airworthiness Directives; Fokker Model F28 Mark 0100 Series Airplanes

Resumo

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Fokker Model F28 Mark 0100 series airplanes. This proposal would require replacement of the autopilot disconnect switches with modified units. This proposal is prompted by several incidents in which the flight crew did not depress both halves of the autopilot disconnect switch during the LAND 2 or LAND 3 approach and, as a result, one autopilot remained engaged. This condition resulted in unanticipated movements of the stabilizer trim and higher than anticipated control forces of the flight controls. The actions specified by the proposed AD are intended to prevent the flight crew from inadvertently disconnecting only one autopilot when both autopilots are engaged, which could result in unanticipated control surface movements.