What happened
On June 24, 2007, a Robin DR 400-140 B, registration F-GKQQ, was conducting a scenic flight near Luzenac, France. The flight, operated by a flying club, included the pilot and three passengers. After departing from Toulouse-Lasbordes, the pilot intended to fly toward the Pyrenees to show the passengers Montségur Castle.
As the aircraft approached the mountains, the pilot encountered significant turbulence and decided to delay a planned eastern bypass of the castle. The aircraft entered a valley oriented north-south, climbing along the eastern slope. During this ascent, the aircraft's speed steadily decreased. Upon reaching a pass oriented east-west, the pilot encountered strong downdrafts caused by southern winds. Realizing the aircraft could no longer gain altitude, the pilot attempted a right-hand turn but instead initiated a sharp left turn. This maneuver led to an asymmetric stall on the left side, causing the aircraft to strike the terrain with a heavy left bank and a nose-down attitude. The aircraft flipped onto its back after impacting the ground. The accident resulted in two serious injuries and one minor injury, while the aircraft was destroyed.
The investigation
The investigation focused on the aircraft's performance and the pilot's flight path. GPS data confirmed the aircraft passed approximately 500 meters west of the castle. Examination of the wreckage showed the engine was delivering low power and the flaps were extended to the 60-degree landing position. No mechanical anomalies were found in the engine to explain a loss of power.
Analysis of the flight trajectory in the final seconds indicated a left bank of approximately 50 degrees with an airspeed between 115 and 130 km/h. According to the flight manual, the stall speed for this aircraft at a 60-degree bank with landing flaps is 123 km/h. The investigation also noted that the pilot's experience in mountainous terrain was limited, and the flight into the mountains was unplanned.
Findings
- The pilot's decision to fly into mountainous terrain was improvised and unplanned.
- There was a lack of familiarity with the specific flight techniques required for managing aircraft attitude in mountain environments.
- The pilot made a late decision to perform a turnaround.
- The pilot likely lost the natural horizon reference common in low-altitude mountain flying, leading to a pitch-up attitude that caused a progressive loss of airspeed.