What happened
On January 16, 2024, a Pilatus PC12, registration N668TW, was conducting a ferry flight from Puerto Rico to Saint-Barthélemy airport. The flight, operated by Tradewind Aviation, was being flown by a two-pilot crew without passengers.
During the final approach to runway 10, the aircraft passed over the Col de la Tourmente. While flying at a low altitude, the aircraft encountered significant turbulence caused by gusty winds. This turbulence destabilized the aircraft, causing a sudden left-hand roll. During this maneuver, the left wingtip struck the branches of a tree. In an attempt to correct the bank, the pilot applied right-hand stick inputs, which brought the right wing as low as approximately two meters from the ground. The crew managed to stabilize the aircraft and completed the landing without further incident.
The investigation
The investigation, conducted by the BEA, utilized data from the aircraft's on-board avionics, airport video recordings, and pilot statements. Investigators compared the flight path and ground speed of the incident to three previous flights conducted under similar wind conditions.
Analysis of meteorological data from Météo France revealed that at the time of the occurrence, the wind was gusting between 16 and 21 knots. The investigation also examined the aircraft's systems, noting that the co-pilot observed a failure in the stall protection system (stick-pusher) and intermittent angle of attack (AOA) warnings. Upon inspection on the ground, the crew discovered that the AOA sensor was cracked and the leading edge of the wing was scratched.
Findings
- The aircraft was operating in a highly turbulent environment due to the local topography and gusty winds.
- The flight path was lower than comparable flights, and the airspeed was estimated to be approximately 10 knots lower than typical approaches in similar conditions.
- Strong downdrafts and gusts caused the aircraft to bank sharply to the left at a low altitude, leading to the vegetation strike.
- The impact with the tree caused damage to the AOA sensor, subsequently disabling the aircraft's stall protection system.