AAIB investigation to Beech 200 Super King Air, G-FSEU
Smoke in the cabin during climb, Doncaster, 28 February 2020
Summary:
While climbing through 8,800 ft after departing Doncaster-Sheffield Airport, the pilots noticed an electrical smell on the flight deck followed by a build-up of grey smoke in the cabin. A MAYDAY was declared and on the approach the flaps were selected down but remained in the retracted position. The aircraft landed without further incident.
The smoke was caused by overheating of the flap motor. The flaps UP limit switch had not operated due to wear in the system and so electrical power continued to be supplied to the motor after the flaps reached the retracted position prior to takeoff. The flap motor Circuit Breaker was found to be intermittent and had not initially tripped to protect the motor from overload.
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