What happened
On 7 September 2024, an ATEC Zephyr 2000, registration EI-GCT, was performing a local flight near Finn Valley Airfield in Co. Donegal. The aircraft, operated for private purposes, was on its third leg of the day, returning to the airfield after a 15-minute flight.
As the pilot reduced engine power to decelerate during the downwind leg of the approach, the engine began to run roughly and the instrument panel started vibrating. In an attempt to clear what was suspected to be carburettor ice, the pilot manipulated the throttle, but the engine eventually stopped entirely. The pilot attempted to restart the engine while maintaining a best glide speed and turning toward the runway. However, the aircraft lost sufficient energy before it could align with the runway, ultimately impacting a boundary hedge approximately four meters short of the landing strip. There were no injuries to the pilot, though the aircraft sustained substantial damage, including a broken left wing and separated landing gear.
The investigation
The AAIU examined the aircraft's engine, fuel system, and the fuel used during the flight. Investigators inspected the Rotax 912-UL engine and its carburettors, finding that fuel was present in the float chambers and the engine was capable of running smoothly at idle. The investigation also analyzed the fuel, which was identified as winter-grade E5 automotive gasoline (MOGAS).
Technical inspections of the fuel system confirmed that the vent lines were functioning correctly and the electric auxiliary fuel pump was operational. The investigation also looked into the potential for vapour lock, noting that while the fuel lines were positioned near hot engine components, the fuel system design included a return line intended to mitigate such issues.