What happened
On 9 November 2002, a Beagle B121 Pup Series 2, registration G-AXJH, was conducting a private training flight near the Compton VOR in Berkshire. The flight was a refresher instrument training session involving a student pilot under the supervision of an instructor. During the session, the aircraft was performing a practice instrument descent toward the navigation beacon, descending from 2,500 feet to approximately 1,430 feet at a rate of 400 feet per minute.
As the student pilot attempted to apply full power to initiate a climb, the engine ceased operation. The crew immediately initiated restart procedures, verifying that the fuel pump and carburettor heat were both in the 'On' position. Because landing checks had already been completed in preparation for the planned approach, the crew was able to declare distress and execute a controlled forced landing in a field roughly one nautical mile from the VOR. There were no injuries to the two crew members and no damage to the aircraft.
The investigation
The investigation focused on the cause of the engine failure and the timing of the application of carburettor heat. The instructor noted that evidence of carburettor icing had been observed and addressed earlier in the flight. During the restart attempt, it was noted that the carburettor heat had been engaged only after the throttle had been closed during the descent. Following the incident, an engineering inspection of the engine was conducted, which revealed no mechanical defects capable of causing the power loss.
Findings
- The engine failure occurred during a period of reduced power settings during a practice descent.
- Carburettor icing was a significant factor, as the engine lost power when the pilot attempted to increase power following a period of low power.
- The application of carburettor heat occurred after the throttle had been closed, rather than before the power was reduced.
- No mechanical or technical defects were found in the engine or its components.