What happened
On 1 August 2006, a Reims Cessna F152, registration G-BHDR, was conducting a private cross-country flight from Cumbernauld Airport to Perth. While flying at approximately 1,700 feet just below the cloud base near the Ochil Hills, the pilot initiated a climb. During the ascent through 2,400 feet, the engine began to run roughly before losing all power.
The pilot attempted to restart the engine while manoeuvring for a landing. Although the engine briefly restarted, it failed to produce sufficient power to maintain altitude. The pilot subsequently executed a forced landing on a hillside slope. During the landing sequence, the left wheel made contact first, followed by the nosewheel, causing the aircraft to flip upside down within several metres of the touchdown point. There were no injuries to the pilot, who was able to exit the cockpit through the window without assistance.
The investigation
The investigation focused on the sudden loss of power and the atmospheric conditions present at the time of the accident. Meteorological data indicated a temperature of 14ºC and a dewpoint of 12ºC at ground level, with higher humidity expected at the flight altitude.
Due to significant vandalism that occurred after the aircraft came to rest on the hillside, the propeller, wheels, and flight instruments were removed or stripped before the aircraft could be examined. Consequently, no physical examination of the engine, fuel system, or induction system was performed by the operator.
Findings
- The aircraft sustained substantial damage, including a separated propeller hub, a bent nose leg, bent wings, and the separation of the tail section from the fuselage.
- The pilot had applied carburettor heat during cruise checks approximately five minutes prior to the engine trouble, but believed carburettor ice formation remained a likely cause of the failure.
- Atmospheric conditions at the time of the accident presented a serious risk of icing in the induction system if carburettor heat was not actively applied.
- The engine failure may have been caused by the engine ingesting water or ice dislodged from the induction system during the period of rough running.