What happened
On 11 September 2021, a Beechcraft Beech 18S, registered F-AZEJ, was participating in the Air Legend air show at Melun-Villaroche aerodrome. The aircraft, operated by Association Amicale Jean- Baptiste Salis, was performing a demonstration flight accompanied by a safety pilot.
Following the takeoff of seven North American T6 aircraft, the pilot of the Beechcraft Beech 18S lined up on runway 01. As the aircraft reached a level attitude during its takeoff roll, it experienced an initial swerve to the left, followed by a much more severe deviation to the right. During this maneuver, the right landing gear ran over the grass.
Upon liftoff, the aircraft entered a sharp left roll, with the left wing tip scraping the runway. The aircraft subsequently veered off the left side of the runway, striking the aerodrome's perimeter fence and crossing an embankment. The right main landing gear detached upon impact with the embankment, causing the aircraft to undergo a ground loop before coming to a stop in a nearby field. The pilot sustained slight injuries, and the aircraft was substantially damaged.
The investigation
The BEA investigation utilized video recordings from spectators, witness statements, and an examination of the wreckage and site. The investigation focused on the meteorological conditions, the takeoff sequence of the formation, and the technical state of the aircraft.
Investigators examined the flight control linkages, engine performance, and trim settings, finding no technical anomalies or engine failures. The investigation also reviewed the takeoff sequence of the preceding T6 aircraft and the wind conditions, which included a 10-knot wind from 230°, creating a tailwind component for the Beechcraft Beech 18S on runway 01.
Findings
- The aircraft was operating with a tailwind component during the takeoff roll.
- The takeoff occurred shortly after a formation of seven T6 aircraft had departed, leaving behind wake vortices and propeller blasts.
- The combination of the tailwind and the atmospheric disturbances from the preceding aircraft likely caused the sudden destabilization of the aircraft during rotation.
- The pilot's decision to use runway 01, rather than the longer runway 28, may have been influenced by the preceding T6 formation, leading to a takeoff in less-than-ideal wind conditions.
- The safety pilot's instinctive action to push the stick forward to keep the aircraft on the ground helped mitigate the severity of the loss of control.