2007 Robin DR400-160 accident at La Teste de Buch (F-GTPP)

Overview and flight details On 26 July 2007, a Robin DR400-160 registered F-GTPP, operated by the Aéroclub du Bassin d’Arcachon, crashed at La Teste de Buch (33) in France. The aircraft was on a local flight with the pilot and three passengers aboard. The pilot had intended to take the three passengers on a sightseeing flight over the Arcachon Basin. The aircraft had been refueled earlier that morning by another pilot after a discovery flight. ## Accident sequence After a taxi check, the pilot lined up on runway 26 and took off. The takeoff roll was described as abnormally long. The aircraft then climbed with a high nose-up attitude and made little altitude gain. At approximately 100 to 150 feet, it turned about 90 degrees to the left in level flight, followed by a brief straight path in slight descent. It then banked sharply left, the left wing dropped suddenly, and the aircraft entered an asymmetric stall with a steep nose-down attitude. It struck trees and the ground and caught fire. ## Damage and casualties The aircraft was destroyed by the impact and subsequent fire. The impact damaged several trees, and vegetation burned over an area of about 1,500 square meters. All four occupants— the pilot and three passengers— were killed. The force of the impact left no possibility of survival. ## Aircraft and weight information The aircraft, serial number 2411, was first registered on 12 April 1999 and had 4,492 hours 20 minutes of time in service at the date of the accident. It was powered by a Lycoming O320 D2A engine and fitted with a Sensenich 74DM6S5-2-64 propeller. The calculated takeoff mass was 1,069.4 kg, exceeding the manufacturer’s maximum takeoff mass of 1,050 kg by about 20 kg. The center of gravity was near the aft limit. ## Investigation findings The engine and accessories were too damaged to determine whether a malfunction had occurred before the accident. A crack in an exhaust tube was found, but it could not be confirmed as pre-impact. Fuel analysis showed the fuel met specifications. The additional quarter-wave silencer installed on the aircraft was damaged in the impact, with no pre-accident damage identified. Test-pilot information indicated that this type of silencer caused a power loss compared with other types, while significantly reducing noise. The propeller pitch affects takeoff, climb, and cruise performance; a smaller pitch reduces takeoff distance and increases climb rate at the expense of cruise speed. ## Environmental and operational context The Arcachon aerodrome is largely surrounded by pine forests, offering few suitable areas for an emergency landing after an engine failure following takeoff. Meteorological conditions were favorable for visual flight, with a wind from 300 degrees at 10 knots. Pilots in the area reported turbulence over the trees at low altitude during initial climb after takeoffs from runway 26, attributed to wind gusts over uneven tree heights combined with thermal convection.