AAIB investigation to Piper PA-28-161 Cadet, G-CEZO
Engine fire on the ground, Fairoaks, 19 September 2015.
Summary:
After completing the pre-flight checks the pilot attempted to start the engine. The engine primer pump was not used as the engine was still hot from an earlier flight, but the engine failed to start. The engine was then primed and a second start was attempted which was also unsuccessful. The engine was re-primed and a third start attempted. During this attempt the pilot initially selected the fuel mixture control to IDLE / CUT-OFF, in an attempt to eliminate excess fuel in the carburettor and engine, before moving the mixture control to FULL RICH. Once again the engine failed to start.
After waiting for a few minutes the engine was re-primed and a fourth start attempted. During the start a significant volume of smoke began to emerge from beneath the engine cowlings. The aircraft was evacuated without injury and the AFRS extinguished a fire which was restricted to the engine bay. Inspection of the engine after the event revealed some evidence of oil leaking onto the exhaust from the lower engine cowling. The fire is believed to have been caused by over-fuelling of the engine and the presence of oil on the engine exhaust.
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