What happened
On December 13, 2004, a Dyn'Aero MCR-01 amateur-built aircraft, registration F-PQUN, departed from Cannes Mandelieu for a local VFR flight. The aircraft was carrying a pilot and one passenger. After flying over Saint Cézaire sur Siagne, the pilot directed the aircraft toward the Audibergue mountain range.
During the flight, the pilot performed a 360-degree left turn near the Saint Martin valley, likely attempting to gain altitude before approaching a mountain pass. As the aircraft approached the pass, the ground speed began to decrease steadily. The aircraft eventually struck a tree and the terrain at an altitude of 4,260 feet in a heavily wooded area. The impact resulted in two fatalities and the destruction of the aircraft.
The investigation
The investigation focused on reconstructing the flight path using data from a Garmin GPS III Pilot and digital photographs recovered from the wreckage. Analysis of the GPS data confirmed that the engine was producing power during the final stages of the flight, as there was no significant deviation in the flight path prior to the speed loss.
Investigators also examined the aircraft's performance capabilities. The MCR-01 has a demonstrated maximum rate of climb of approximately 500 ft/min under standard conditions. The investigation noted that to clear the terrain between Saint Cézaire and the accident site within the recorded five-minute interval, a vertical climb rate exceeding 540 ft/min would have been required.
Findings
- The pilot lacked specific mountain flying techniques, particularly regarding the safe crossing of mountain passes and the use of appropriate maneuvers like the valley turn.
- In an attempt to increase the rate of climb, the pilot reduced the airspeed below the optimal climbing speed, which actually decreased the aircraft's performance.
- The pilot's decision to fly toward the Audibergue mountains without specific preparation or assessment of the terrain's difficulty contributed to the accident.
- The aircraft lacked a stall warning system, which likely prevented the pilot from recognizing the onset of the stall.
- The aircraft likely entered a stall at a low altitude due to an excessive angle of attack or a load factor induced by a turning maneuver, possibly an attempt to avoid power lines located near the pass.