What happened
On 25 February 2012, a Corben Junior Ace Model E, registration G-BSDI, was involved in a landing accident at White Ox Mead Airstrip near Bath during a private flight. After starting the engine, the pilot taxied approximately 510 metres across the grass Runway 2/4 to the Runway 06 threshold. During this taxi, the pilot noted a 100 rpm drop in engine performance on two separate occasions when applying carburettor heat.
Upon reaching the threshold, the pilot performed pre-takeoff checks, applying carburettor heat for 30 seconds. Although the engine initially produced full power, the aircraft experienced a significant loss of power after climbing to 50 feet. Realising the remaining runway length was insufficient to continue the flight, the pilot closed the throttle and landed the aircraft in a stubble field to the right of the runway. The impact resulted in a broken main landing gear cross-member, though there were no injuries to the pilot.
The investigation
The investigation examined the engine performance and the environmental conditions at the time of the accident. While no specific weather observations were recorded at the airstrip, data from Bristol Airport indicated a surface temperature of +9ºC and a dewpoint of +5ºC, suggesting high humidity and a significant risk of icing.
Following the accident, the pilot conducted a fuel flow check and an examination of the carburettor, neither of which revealed any mechanical defects. The investigation focused on the accumulation of ice within the carburettor during the taxi phase and the effectiveness of the heat application prior to takeoff.