What happened
On 22 June 2010, a Jabiru SK, registration G-JABA, was performing practice circuits at Whiterashes Airstrip in Aberdeenshire. While flying the downwind leg of the initial circuit, the pilot reduced engine power to approximately 2,000 rpm. During the execution of pre-landing checks, the engine briefly hesitated and then stopped.
Realising the aircraft was at an insufficient altitude to return to the airstrip, the pilot opted to perform a forced landing in a crop field located roughly one mile west of the airfield. An attempt to restart the engine using the electric fuel pump and starter motor was unsuccessful. The aircraft landed in the field, which was covered in crops that hid a rough underlying surface. The impact caused damage to the propeller, the left wingtip, the left main landing gear, and the nose leg. The pilot was uninjured.
The investigation
The AAIB examined the engine following the accident. The investigation confirmed that the engine turned freely and the ignition system was operational. No fuel leaks were identified, and the main fuel tank contained enough fuel for the flight. A strip inspection of the engine revealed no mechanical defects that would have caused the failure.
However, meteorological data indicated that conditions at the surface and at 1,000 feet were conducive to significant carburettor icing at descent power settings. Fuel was found in the carburettor float chamber during the examination.
Findings
- The engine failure was likely caused by carburettor icing due to the lack of carburettor heat application.
- The meteorological conditions were highly favourable for the formation of serious icing at low power settings.
- The rough nature of the landing site, obscured by crops, contributed to the damage sustained by the aircraft.