France

Most likely, the fuel selectors were in the 'Nose' position at start-up. The pilot thought that the main tanks were selected. He probably took off and flew on the 'Nose' tank, common to both engines, without realizing it. At the end of the downwind leg, having probably consumed all the fuel available in the 'Nose' tank, the right engine stopped. In this hypothesis, the left engine would also have suffered the effects of a fuel supply failure. This hypothesis is consistent with the observation of the position of the left and right fuel selectors on 'Nose' in the wreckage, and the pilot's initial testimony that the selectors had not been manipulated. The pilot, who was no longer able to hold the landing and was too far from the runway to reach it, was unable to avoid colliding with trees during the forced landing. His attention was focused on the aircraft's path, and he didn't think to switch off the battery, magnetos or the fuel supply system. During the collision with trees, the right engine and wing were torn off, and a fire broke out.
It is considered that the following factors may have contributed to the probable selection of fuel selectors on the 'Nose' instead of the main tanks:
- The pilot's lack of experience on type, which could have exposed him to a selection error and which was not conducive to his detection during the pre-start-up and pre-takeoff checks;
- The ergonomics of the fuel tank selector levers, which could have led him to think that they were positioned on 'Front';
- The pilot's state of health and fatigue at the time he undertook the flight, which was likely to have impaired his cognitive abilities.
- A form of objective-destination linked to the accumulated delay in repairing the cylinder may have contributed to the pilot's decision not to postpone the flight, despite his altered general state;
- A misrepresentation of the position of the fuel selectors may have led the pilot not to change their position when the engine problem occurred.

The accident was the consequence of a premature descent during the approach. The pilot started the descent on the base leg, whereas mountain landing practices call for a descent on final approach after interception of the descent plan, combined with an erroneous assessment of the aircraft's position in relation to the final descent plan. Investigations revealed that the aircraft was flying at an altitude of 6,600 feet during the last turn, about 400 feet below the altitude indicated on the approach chart.
The following factors may have contributed to the accident:
- The period of training received by the pilot was probably insufficient;
- A lack of landing experience at Courchevel;
- A misunderstandings between the pilot and the passenger seated on the right about his role during the flight, himself being an airline pilot and instructor.

The accident was the result of the combination of the following factors:
- The pilot initiated the descent too late, causing the aircraft to approach well above the glide,
- The pilot continued the approach with an unstabilized airplane nor in speed nor on the glide,
- The airplane landed halfway down the runway, reducing the landing distance available,
- The speed upon touchdown was recorded at 119 knots, 30 knots above the recommended speed in the flight manual,
- The braking coefficient was considered as medium because of a wet runway surface,
- The airplane suffered an aquaplaning effect when the pilot initiated the braking procedure.

The exact cause of the loss of power on the left engine could not be determined. The pilot, concentrating on monitoring the approach parameters, did not immediately realize the left engine malfunction. He noticed that the aircraft's rate of descent was too high to follow the standard approach slope. The pilot first attempted to go around and reconfigured the aircraft to do so by retracting the landing gear and flaps. In spite of these actions, the pilot noticed that the power delivered by the aircraft's engines did not allow him to recover the plane and understood, by being aware of the action of his right foot on the rudder pedal, that the power delivered by the left engine was abnormally low. Given the low height of the plane at the time of this observation, the pilot decided to land in the country. Contributing to the high rate of descent after the occurrence of the left engine malfunction was the fact that the drags were extended at the time the engine power decreased and the fact that the left propeller probably windmilling until the landing.

The following findings were identified:
- GASC (Groupement d’avions de la sécurité civile) has a small resource of Tracker pilots;
- Without a co-pilot, the pilot is deprived of the usual cross-checking of piloting decisions and actions;
- The pilot has little experience on established firefighting missions. He has never carried out a mission of this nature in a single-pilot aircraft;
- Certain limitations of the flight envelope are unknown to pilots, particularly at high weight and in steep turns;
- Pilots have little knowledge of the aerological phenomena associated with certain fires, and the associated turbulence;
- With the implementation of the Tracker withdrawal, pilots are concerned about their future within the GASC;
- Fatigued from sustained activity, the pilot had a false understanding of the situation;
- The pilot suffered from overconfidence;
- The pilot did not perceive the terrain. He flew a little low as he approached the hill ;
- He adopted a trajectory very close to the flame front and did not anticipate the risk of turbulence;
- Focused on a dwelling to protect, he did not detect the inappropriate altitude of his plane and maintained a strong bank;
- The left wing underwent a local stall causing a steep left bank, which caused the pilot to recover the aircraft too low in relation to the height of the trees, which he had a false idea of.