The aircraft, a Stampe SV4C(G) (G-AWEF) was taking part in a formation display practice with three other similar aircraft. Whilst practicing a new manoeuvre involving a synchronised line abreast stall turn, G-AWEF was seen to enter a spin. The aircraft did not fully recover from the spin before striking the ground fatally injuring the pilot.
No evidence was found of any pre-existing fault or damage to the aircraft which could have caused the spin or prevented the aircraft from recovering from the spin.
Flight tests conducted during the investigation showed that the most likely reason the aircraft entered a spin was that either too much aft stick was applied before the yawing turn was complete or that the rudder was not centralised when the pull-out was commenced. The investigation identified several reasons why this may have occurred.
The investigation highlighted the importance of obtaining guidance and mentoring from an experienced display authorisation evaluator when upgrading a display authorisation.