What happened
On August 31, 2007, at 15:47, a Gryf MD 3 Rider ultralight, identified as 05-JZ, was performing a flight from Gap aerodrome to Blois. The aircraft took off from runway 21 shortly after another ultralight of the same model. Witnesses at the airfield observed that after a very short acceleration run, the aircraft rotated with an excessive pitch-up attitude. The aircraft's trajectory then veered sharply to the right, losing altitude and eventually colliding with a refueling truck parked near the control tower.
The investigation
The investigation examined the wreckage and the flight circumstances. Analysis of the engine confirmed it was delivering power to the propeller at the moment of impact. The flight control cables were intact, and the wing flaps were set symmetrically at 15 degrees. Crucially, the investigation found that the elevator trim tab was at its extreme nose-up limit, with the electric control motor's position indicator also at its limit.
While the aircraft's total weight of 446 kg was within manufacturer limits, the investigation noted that the pilot's checklist, found in the wreckage, did not include an item for verifying the elevator trim position before takeoff. Furthermore, although the AFIS agent had informed the pilot of the wind conditions (10 to 15 knots from 080°), the pilot proceeded with the takeoff on runway 21, which resulted in a significant tailwind component.
Findings
- The primary cause of the loss of control was the failure to verify the elevator trim position prior to takeoff, leaving the aircraft in a nose-up configuration.
- A contributing factor was the decision to take off with a tailwind component, which affected the aircraft's trajectory and reduced the effectiveness of the flight controls.
- It was noted that the pilot did not request an alternative runway direction despite having the regulatory authority to do so to avoid the tailwind.