What happened
On 3 June 2018, a Jodel D120 (registration G-AVYV) was performing a private flight from Shifnal Airfield to Sandown Airfield. During the flight, the pilot noted the engine running roughly at approximately 400 ft, which was resolved by applying carburettor heat. Upon arriving at Sandown, the pilot noticed the engine running slightly rough again while on the downwind leg. To address this, the pilot increased the RPM and turned the electric fuel pump off, which temporarily smoothed the engine's operation. The pilot did not recall switching the fuel pump back to the on position.
During the landing phase, the aircraft bounced and floated along the runway. Following a second bounce, the pilot initiated a go-around. At an altitude of approximately 200 ft, the engine lost power completely. The pilot applied carburettor heat, which provided a momentary recovery before the engine failed again. The pilot then executed a forced landing on the fairway of the 8th hole at the Shanklin and Sandown golf course. The pilot sustained one minor injury.
The investigation
The AAIB examined the aircraft and the circumstances surrounding the engine failure. Post-accident inspections of the engine revealed that it rotated freely, fuel was present in the tanks, and both fuel pumps were functional and full of fuel. The fuel filters were also found to be clean. The investigation considered the impact of using Mogas fuel and the atmospheric conditions at the time of the accident.
Findings
- The exact cause of the engine failure could not be definitively established.
- Carburettor icing is a potential cause, as the engine briefly recovered when carburettor heat was applied; weather data indicated conditions favorable for icing.
- The formation of fuel vapour in the fuel system may have interrupted the fuel flow, a possibility increased by the pilot having turned the electric fuel pump off during the downwind leg.
- The use of Mogas fuel may have contributed to the likelihood of both carburettor icing and fuel vapour lock.