What happened
On 17 October 2014, a Piper PA-28-161 Cadet, registration G-BXJJ, was conducting a circuit training flight near White Waltham Aerodrome when the engine lost power during the base leg of the approach. The flight crew, consisting of an instructor and a student pilot, was performing routine maneuvers when the engine failed to respond to a throttle advancement.
Upon realizing the power loss, the instructor took control of the aircraft and declared a MAYDAY. During the subsequent descent, the crew identified power cables obstructing the intended approach path. To avoid a potential stall while attempting to clear the cables, the instructor opted to fly under them. This maneuver resulted in the aircraft landing short of the intended field and striking a hedge. The impact caused substantial damage to the aircraft, including both wings detaching from the fuselage. The two crew members sustained minor injuries and managed to escape through a side window after finding the cabin door blocked by the aircraft's position.
The investigation
Investigators examined the aircraft's mechanical systems and found no evidence of fuel contamination or mechanical defects in the fuel system or throttle controls. The engine was removed and tested, performing normally on a test stand.
Atmospheric data from nearby London Heathrow indicated high humidity, with a temperature of 15°C and a dew point of 14°C. The investigation also noted that the carburettor heat had been left in the 'on' position following the downwind leg, and the engine was likely not at full operating temperature during the power reduction phase of the approach.