The accident occurred at the start of the return flight after participation in a vintage aircraft rally for which no demonstration flight was planned. After flying over the runway centreline, a half-roll to the left was performed, followed by a descending half-loop. This manoeuvre was not carried out at the altitudes required for aerobatics at Lens Bénifontaine Aerodrome. The height at which the manoeuvre began did not provide a sufficient safety margin to avoid collision with the ground at the end of the manoeuvre. The pilot's recent experience with this type of flight, in this type of aircraft and at Lens Bénifontaine Aerodrome, meant that he lacked sufficient points of reference for performing aerobatic figures.
The investigation did not find any technical failures. It could not be determined whether the inputs on the flight controls were deliberate or the result of a medical problem.