The Incident
On 8 September 2012 at 1136 UTC, a de Havilland DH89A Rapide Dragon, registration G-AIYR, was being prepared for a commercial passenger flight at Duxford Aerodrome in Cambridgeshire. The aircraft, manufactured in 1943 and equipped with two De Havilland Gipsy Queen 3 piston engines, had one pilot and seven passengers on board.
The pilot started the left engine first. After priming, the right engine was started. Immediately after the right engine started, the pilot observed a flame appearing to originate from the outboard section of its engine cowling. Believing the right wing had caught fire, he shut down both engines.
The pilot then assisted with passenger evacuation, which had already been initiated by ground crew. Ground crew tackled the fire with hand-held appliances and had extinguished the fire by the time the aerodrome fire service arrived on scene.
Damage
The fire caused damage to the outer section of the right stub wing and the inner section of the lower right mainplane.
Investigation
The aircraft operator conducted an investigation into the incident. No injuries were sustained by the pilot or the seven passengers.
Probable Cause
The investigation concluded that the probable cause of the fire was over‑priming of the hot engine, leading to the ignition of overflowed fuel.