What happened
On 4 June 2015, a Pegasus XL-Q, registration G-MTYF, was performing a private flight departing from Over Farm Airfield in Gloucestershire. Approximately 30 seconds after departing from Runway 16, while at an altitude of roughly 500 ft, the single Rotax 462 engine experienced a momentary loss of power. The pilot initially attempted to identify an emergency landing site, but after the engine briefly regained power, a wide left turn was initiated to return to the airfield.
During this turn, the engine lost power a second time and ceased functioning entirely. Realising that a return to the runway was not possible, the pilot attempted to land on the airfield but instead touched down at an angle of approximately 20 degrees to the runway. The aircraft entered a field of rapeseed bordering the runway, which caused the nose landing gear to collapse. There were no injuries to the pilot, who was able to exit the aircraft unassisted.
The investigation
The investigation focused on the mechanical cause of the engine failure and the pilot's pre-flight actions. The pilot identified that the carburettor float chamber had been improperly reinstalled following a routine procedure. To assist with engine priming, the pilot regularly removes the float chamber to manually fill it with fuel; however, on this occasion, the component was not seated correctly, allowing air to be drawn into the carburettor.
Additionally, the investigation established that the pilot had omitted a standard two-minute power assurance check, which is a regular part of his flight preparation. The pilot noted that this check likely would have revealed the fuel delivery issue while the aircraft was still on the ground.