What happened
On April 30, 2015, a Pioneer 200S ultralight, identified as 86-MN, departed from Belvès for a sightseeing flight. The aircraft was powered by a Rotax 912 ULS engine and was carrying a pilot and one passenger. Approximately 20 minutes into the flight, while cruising at an altitude between 1,800 and 2,000 feet near Saint-Vincent-de-Cosse, the engine suffered a sudden failure.
In response to the engine loss, the pilot attempted an emergency landing in a field previously flown over. After an unsuccessful attempt to restart the engine, the pilot performed a 270-degree turn to realign the aircraft with the landing site. During the approach, the pilot deployed a single notch of flaps to manage airspeed. As the aircraft crossed the Dordogne river, it encountered light turbulence and a loss of altitude. The right wing spar struck the top of a tall tree at the edge of the field, causing the aircraft to strike the ground in a steep nose-down attitude. While the pilot escaped the wreckage with injuries, the passenger succumbed to her injuries later that day.
The investigation
The investigation focused on determining the cause of the engine failure and the circumstances of the impact. Investigators examined the fuel system, including the tanks, lines, and carburetors. While slight pollution was noted in the fuel tank and strainer, no evidence of contamination was found downstream in the lines or carburetors, and no obstructions were identified. The mechanical fuel pump and the ignition system were found to be in good working order.
An inspection of the Rotax 912 ULS engine block revealed that the engine was well-lubricated and the internal moving parts were functional. The reduction gear and accessory housing showed no damage. Ultimately, the investigation could not determine the specific cause of the initial engine failure.
Findings
- The engine failure necessitated an emergency landing, though the pilot's chosen flight path and altitude initially provided access to a clear landing area.
- The insufficient clearance of the chosen flight path relative to obstacles at the field's edge was the primary cause of the accident.
- This margin of safety was further reduced by aerodynamic effects, specifically the loss of altitude experienced during turbulence near the river.