During a cross-country flight in a mountainous region, the pilots followed a circular route out of Gap-Tallard, stopping at Mont-Dauphin Saint-Crépin aerodrome and then flying over Barcelonnette-Saint-Pons aerodrome via the Col de Vars mountain pass. The aeroplanes, in groups, were following each other on the route in the afternoon.
After the stop at Mont-Dauphin Saint-Crépin aerodrome, the pilots of the SR20 and the FR172 took off again at an interval of three hours and both entered the valley rising to the Col de Vars mountain pass at an insufficient height. The performance of both aeroplanes in view of their weight, the flight altitude and the weather conditions that day was not sufficient for clearing the pass given the height at which each of the two aeroplanes had entered the valley.
According to the pilot of the SR20, he moved towards the centre of the valley to put distance between him and another aeroplane which was lower than him. He then encountered difficulties in gaining altitude. The pilot realised at a late stage that he would not be able to clear the mountain pass. The passenger asked the pilot to carry out a right-hand U-turn several times; the latter did not react as he was concerned about getting close to the terrain and experiencing downdrafts near the east slope situated on the other side of the valley. When he realised that he would not be able to cross the Col de Vars pass, the pilot looked for a suitable site for an emergency landing. He identified a wooded area on his right which he believed to be his only option given the environment, and tried to land on the tree tops.
When the pilot of the Cessna 172 entered the valley, he thought that the aeroplane did not climb due to the downdraft effect. He then thought he would be able to use the updrafts along the slope to gain altitude but was surprised that the aeroplane did not climb quickly enough. When he realised that he had no other option for continuing the flight, he changed direction midway to the Col de Vars pass and then decided to abort the flight and land in a grass field that seemed suitable to him.