The landing was after a completion of the third of a series of aerobatic training flights. The pilot had taken control from the student for the landing and joined crosswind for a right hand circuit landing on Runway 05 at Sleap Airfield. The wind was reported as from 080º at 10 kt. During the approach onto final the pilot was aware that the aircraft was closer to the threshold than anticipated and adjusted the flight path accordingly. Flare and touchdown were normal, but during the ground roll the aircraft did not decelerate as expected. The left wing then dropped and the aircraft then ground looped to the right causing damage to the wing, tail wheel and rudder. The pilot and student evacuated the aircraft without injury.
Although the reported wind favoured Runway 05, the previous landing aircraft had made the decision to land on another runway as they felt there may have been a tailwind on Runway 05 and other observers at the airfield later reported to the pilot of G-BTUL that the wind at that time appeared to them to be from south-southwest, which would have resulted in a tailwind on Runway 05.
Examination of the aircraft shortly after the accident revealed that the left main landing gear had collapsed and that it was possible that this occurred during the landing roll precipitating the initial wing drop leading to the ground loop.