History of the Flight
The day before the accident, the pilot took off from Brive-Souillac airport with his family, intending to return to Cannes. Weather conditions forced a diversion to Langogne-Lespéron aerodrome, where he landed at approximately 13:30. The next day, at around 12:20, the pilot, accompanied by his wife and three children, took off from unpaved runway 22 at Langogne-Lespéron for Cannes-Mandelieu airport. The aeroplane was in flaps-retracted configuration. Approaching the opposite end of the runway at an estimated speed of 65 kt, the pilot pulled on the stick to take off. The aeroplane barely lifted off before touching down again, then overran the runway with a slight deviation to the left. It continued for about 100 m and stopped in a thicket.
Aerodrome and Weather Information
Langogne-Lespéron aerodrome is at an altitude of 3,339 ft. The take-off runway is unpaved runway 22, with an average downward slope of 1.1% and a take-off distance available of 883 m. The last third has a mainly downward slope. The runway is covered with sparse grass, thicker on the second half. The VAC chart restricts the aerodrome to based aircraft, mountain-flying rated pilots, or those who have done a reconnaissance with an instructor within the last 12 months. Weather conditions included thundery showers the night before, overcast sky at around 1,000 ft ceiling, light north-westerly wind of about 3 kt with gusts up to 7 kt, visibility >10 km, and outside temperature 13 °C. A local flying club member noted that the runway was very wet due to heavy rainfall.
Aircraft and Pilot Information
The aircraft was a SOCATA TB20, registered F-GDNU, with a maximum take-off weight of 1,400 kg. The pilot calculated the take-off weight at around 1,350 kg and balance within limits. The pilot, aged 48, held a PPL(A) issued in 2014, with about 400 flight hours, 300 of which on F-GDNU. He did not hold a mountain rating and had never been to Langogne-Lespéron before. The pilot stated that at the runway midpoint the speed was 55 kt; he expected to reach rotation speed in the second half, but wet, muddy conditions limited acceleration to 62 kt. He intended to take off with flaps retracted. The flight manual recommends increasing take-off distances for wet grass (25% on short, wet grass) and does not provide performance tables for flaps-retracted configuration. The rotation speed with flaps in take-off configuration (10°) is 68 kt. The estimated take-off run on a dry paved runway for 1,350 kg at the given conditions is about 450 m; on short, wet grass it would be about 550 m, not accounting for slope or grass variations. The GNSS data showed the take-off run started 60 m from the threshold, reducing the available distance to about 820 m.
Conclusions
According to the BEA investigation, the aeroplane's take-off performance in flaps-retracted configuration, close to maximum weight, combined with the unpaved, wet runway condition, did not allow sufficient speed to take off. The start of the take-off run 60 m from the threshold further reduced the available distance. The pilot applied nose-up input, causing a slight lift-off followed by touchdown, overrun, and a stop in vegetation after about 100 m. The investigation identified contributing factors: the decision to take off with a configuration for which performance could not be calculated using the flight manual, and early rotation at a speed lower than specified for the take-off configuration.