What happened
On 18 September 2011, a modified Kolb Twinstar MKIII, registration G-MYOR, was performing high-speed taxi runs on the grass runway 25 at Mount Airey Airfield, Yorkshire. The pilot was conducting these tests following maintenance work on the aircraft's fuel system components. During the taxi, as the aircraft reached roughly 35 mph at the midpoint of the runway, it unexpectedly lifted off the ground. The pilot, who had been maintaining the control column in a fully aft position, realized the aircraft was airborne and determined there was insufficient runway length remaining to continue the takeoff. Consequently, the pilot executed a circuit to attempt a landing.
During the final approach, the aircraft was at a height of approximately 15 ft and flying at roughly 10 mph above its stall speed with full flaps extended. At this stage, the aircraft lost flying speed and dropped into a field located about 30 ft short of the runway threshold. The impact caused damage to the cockpit structure and the landing gear, though the pilot sustained no injuries.
The investigation
Investigators examined the circumstances surrounding the unexpected liftoff and the pilot's subsequent approach. The pilot had very limited experience with this specific aircraft type, having flown only one short sortie in the tail-dragger model previously. The investigation noted that the pilot had been attempting to lift the tail by moving the control column forward, but had failed to do so, leaving the column fully back during the taxi run. The pilot suggested that his lack of experience with the aircraft's handling characteristics contributed to the loss of airspeed during the landing attempt.