What happened
On October 29, 2005, a Wassmer WA 52 aircraft, registration F-BTLR, was conducting a flight from Plessis-Belleville to Graulhet. Upon arrival at Graulhet, the pilot announced a standard integration for landing on runway 10. Witnesses observed that the aircraft's approach was unstable in both roll and pitch. During the flare, the aircraft began to sink, prompting the pilot to apply full power for a missed approach. Observers noted a high pitch attitude during the application of power and a weak initial climb gradient.
At approximately 300 feet, the aircraft entered a left turn. Due to the wind conditions, the aircraft drifted into the low-altitude downwind leg of the circuit. While established on the downwind leg at an altitude below 500 feet, the aircraft exhibited a significant pitch attitude before entering a spin. The aircraft struck the ground in a flat spin and subsequently caught fire. The wreckage was located approximately 1,000 meters north of the runway.
The investigation
The investigation established that the aircraft struck the ground with high vertical velocity and minimal horizontal speed, while the engine was still producing power. The impact and subsequent fire destroyed most of the airframe, leaving only fragments of the wings, vertical stabilizer, and rudder intact.
Investigators examined the meteorological conditions, noting that the automatic weather station at Montredon-Labessonnie recorded winds of 16 knots from 130 degrees with gusts up to 37 knots, accompanied by a SIGMET for severe turbulence. While the pilot had avoided Castres due to known turbulence, he chose Graulhet because of his familiarity with the airfield. However, local pilots had grounded all flights that day due to the strength of the wind and turbulence generated by the surrounding terrain. This specific aerological hazard was not noted on the Graulhet aerodrome chart.
Findings
- Insufficient aircraft control within highly turbulent atmospheric conditions.
- The pilot's failure to divert to an alternative airport despite the deteriorating weather.
- Severe turbulence and high wind gusts significantly impacted the aircraft's stability during the missed approach.
- The pilot had very limited experience on this specific type, having flown it only once a week prior to the accident.