Airworthiness Directives; Dornier Model 328 Series Airplanes Equipped with Honeywell GP-300 Guidance and Display Controller

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Dornier Model 328 series airplanes. This action requires modification of certain Honeywell GP-300 guidance and display controllers. This amendment is prompted by reports of smoke and fumes, due to a defective light bulb, emitting from the Honeywell GP- 300 guidance and display controller; and a report of failure of the autopilot to disconnect manually. The actions specified in this AD are intended to prevent a defective light bulb from causing a short circuit that emits smoke and fumes into the cockpit; or causing damage to the circuit cards and various components, which may lock the autopilot into the engaged mode. Locking of the autopilot into the engaged mode could lead to the inability of the pilot to disconnect the autopilot, which could result in reduced controllability of the airplane.