What happened
On July 26, 2007, a Robin DR400-160, registration F-GTPP, operated by the Aéroclub du Bassin d’Arcachon, was performing a local flight from La Teste de Buch. The pilot was accompanied by three passengers. During the takeoff roll on runway 26, the aircraft experienced an abnormally long ground roll. Upon rotation, the aircraft maintained an excessive pitch attitude, struggling to gain altitude.
At an altitude between 100 and 150 feet, the aircraft entered a 90-degree left turn in level flight. After following a straight path in a slight descent, the aircraft banked sharply to the left. This caused the left wing to drop, leading to an asymmetric stall and a steep dive. The aircraft struck trees and caught fire, resulting in one fatality (the pilot) and the total destruction of the aircraft.
The investigation
The investigation focused on the aircraft's weight, performance, and configuration. Investigators determined that the aircraft's takeoff mass exceeded the manufacturer's maximum allowable limit of 1,050 kg. Additionally, the aircraft was equipped with a quarter-wave silencer, which is known to cause a loss of engine power compared to standard configurations.
Analysis of the wreckage and eyewitness accounts from glider pilots indicated that the engine appeared to be delivering low power relative to its noise level. The investigation also examined the elevator trim position and the pilot's recent flight history. While the engine and propeller were heavily damaged, no mechanical failure was identified as the primary cause of the accident. The investigation also noted that the aircraft's flight manual did not include an addendum regarding the installation of the silencer.
Findings
- The primary cause of the accident was inappropriate takeoff technique leading to a flight in the second regime (low-performance climb).
- The aircraft was operating at a weight exceeding its maximum takeoff mass, which significantly degraded climb performance.
- The pilot's attempt to maneuver the aircraft into a turn at low altitude reduced the margin to a stall, resulting in a loss of control.
- The pilot lacked sufficient knowledge regarding the specific performance limitations of this particular aircraft.
- The installation of a quarter-wave silencer contributed to reduced engine power.