What happened
On August 31, 2024, an AS 202/15-1 Bravo, registered F-GSTL, was performing a local flight departing from Guéret-Saint-Laurent aerodrome. The aircraft was carrying the pilot and two passengers. During the initial climb, at an estimated altitude of 240 feet, the pilot experienced abnormal aircraft movements and felt the plane sinking. Without realizing the aircraft was losing altitude, the pilot continued the climb until the aircraft struck trees in a wooded area. The impact caused the fuselage to break into two parts, and the aircraft came to rest upside down. The occupants were able to evacuate the wreckage unaided, though the pilot sustained slight injuries and the aircraft was destroyed.
The investigation
The BEA examined the wreckage and the pilot's statements to reconstruct the flight sequence. The investigation noted that the aircraft was operating at a weight of approximately 970 kg, which was within its permitted envelope, though close to its maximum takeoff weight. The investigation also reviewed the pilot's recent flying history, noting that while he held a valid license, he had not flown this specific aircraft type in over four years and had only logged a small amount of recent flight time in a different aircraft type. The investigators also analyzed the aerodynamic conditions of the flight, specifically focusing on the aircraft's performance during the climb phase in high temperatures.
Findings
The investigation established that the primary cause of the accident was that the pilot maintained a flight on the backside of the power curve after takeoff. By adopting a steep nose-up attitude, the pilot prevented the aircraft from accelerating to the required climb speed, leading to a state where the aircraft could no longer maintain level flight without losing altitude. Several contributing factors were identified, including:
- The pilot's limited recent flying experience.
- The pilot's lack of recent experience specifically with the AS 202/15-1 Bravo.
- An imperfect theoretical understanding of the dangers associated with the backside of the power curve.
- The lack of a formal rule within the flying club regarding recent experience requirements for specific aircraft types.