What happened
On 3 November 2001, a Reims Cessna F172N Skyhawk, registration G-BSHR, was conducting a training flight near Exeter, Devon. After completing pre-flight checks and verifying fuel quality, the pilot departed the airfield. During the initial climb, the pilot leveled the aircraft at 2,000 feet to remain below the cloud base.
Shortly after the pilot switched the fuel tank selector from the 'BOTH' position to 'LEFT', the engine began to run roughly. Although the pilot immediately returned the selector to 'BOTH' and requested a rejoin to the airfield, the engine suffered a total loss of power at approximately 1,800 feet. The pilot attempted three unsuccessful restarts using various fuel tank selections, but the propeller had already stopped spinning.
After declaring a Mayday, the pilot selected a field for an emergency landing. Upon touchdown, the aircraft's nose wheel dug into the soft ground, causing the aircraft to become airborne again and strike a hedge and several trees. The 1 occupant sustained minor injuries, but the aircraft was destroyed.
The investigation
The AAIB examined the wreckage at a hangar in Exeter. Investigators found that the fuel in the gascolator was clean, free of water, and showed no signs of contamination. The engine and its associated systems, including the throttle, mixture, and carburettor heat, were found to be in good working order. Subsequent test runs of the engine on a test bed revealed no mechanical faults.
Meteorological data indicated that at the time of the accident, the atmospheric conditions at 2,000 feet presented a high probability for serious carburettor icing at any power setting. The investigation also noted that the pilot had been involved in a similar engine failure incident earlier that year in a different aircraft.