What happened
On 12 August 2013, a DH60G Gipsy Moth, registration G-AAZG, was conducting a private flight near Canons Ashby, Northamptonshire. The flight, which included the pilot and one passenger, began with the engine operating normally as the aircraft climbed to 1,200 ft. The pilot performed a sequence of manoeuvres consisting of two medium banked turns and a gentle wingover, followed by another steep left turn.
During the final steep turn, the engine ceased operation. This loss of power caused the aircraft to enter a left-hand spin. Although the pilot successfully recovered from the spin, the low altitude left insufficient room to avoid obstacles. The pilot was forced to execute an emergency landing in an isolated grassy area containing trees. During the descent, the aircraft struck a ridge and furrow, resulting in the destruction of the landing gear and significant damage to the forward fuselage and wings. Both the pilot and the passenger sustained serious injuries.
The investigation
The investigation examined the aircraft's recent maintenance and operational history. It was noted that the aircraft had recently undergone re-weighing, a process that involved draining and refilling the fuel tank with the same fuel. Following this, the aircraft had completed approximately five hours of flight time, including two refuellings at a licensed aerodrome.
Investigators also reviewed the engine's performance history, noting reports that the engine had been consistently reliable. No specific cause for the sudden engine stoppage was identified during the examination of the engine or the fuel system.