AD 98-21-13 Amendment 39-10822

This amendment adopts a new airworthiness directive (AD) that applies to certain British Aerospace Jetstream Model 3101 airplanes. This AD requires replacing the elevator trim servo motor with a new motor of improved design; and inspecting the cable tension and electrical operation of the elevator and trim tab for proper operation, and making any necessary adjustments. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for the United Kingdom. The actions specified by this AD are intended to prevent the elevator trim servo motor drive gear assembly from remaining engaged when the autopilot is disengaged, which could result in the pilot having to manually overpower the elevator trim control and possibly lose directional control of the airplane during critical phases of flight.