What happened
On 17 March 2004, a Eurocopter EC120B, registration G-EMCM, was engaged in a conversion training flight at Kidlington, Oxfordshire. The flight involved an instructor and a student pilot, who was transitioning from a Private Pilot's Licence to a more advanced rating.
While operating from the airfield's grass training area, the student pilot attempted to lift the helicopter into a hover before commencing a circuit. As the aircraft became light on its skids, it began drifting toward the right. During this drift, the right-hand skid encountered either a clump of grass or an uneven patch of ground. This contact initiated a roll to the right. The instructor attempted to intervene by applying full left cyclic control, but the aircraft continued to tilt until it came to rest on its side. The engine was shut down immediately, and all three occupants evacuated the aircraft through the left-hand doors without injury. The aircraft sustained substantial damage.
The investigation
The investigation examined the mechanics of the roll and the pilot's response. It was established that the aircraft's movement toward the right led to the right skid catching an obstruction, which served as a pivot point. The investigators analyzed the effectiveness of the cyclic inputs used by the instructor and the physical phenomenon of the roll itself.