What happened
On February 8, 2022, an Air Tractor AT802 was performing a landing approach at the Trilahue Aerodrome (SCYB) in the Biobío Region of Chile. The aircraft had been engaged in aerial firefighting operations and was returning to the aerodrome to refuel following water drops.
As the pilot was on final approach to runway 18, the aircraft's flight path was significantly lower than the authorized approach path. During this phase, the pilot observed a helicopter with active rotors positioned at a helipad near the right side of the runway threshold. This observation caused a sudden distraction. The pilot subsequently applied an abrupt nose-up attitude change, which caused the aircraft to lose airspeed and enter a stall at a very low altitude. The aircraft struck the ground approximately 218 meters before the threshold of runway 18. The pilot survived the impact without injury, though the aircraft sustained substantial structural damage, including fractured wing sections, deformed control surfaces, and a damaged landing gear.
The investigation
DGAC Chile investigators examined the aircraft's maintenance records, flight logs, and the physical wreckage. The investigation included a review of video footage of the approach and an analysis of the aerodrome's runway configuration.
Investigators found that the aircraft was properly maintained and that the pilot held a valid commercial license. The investigation also noted that the aircraft was utilizing an area of asphalt approximately 170 meters before the current official threshold of runway 18, which corresponded to an old runway marking. This area was not authorized for landing operations. The analysis of the video footage confirmed that the aircraft's pitch increased sharply during the final moments of the approach, leading to the loss of lift.
Findings
- The primary cause of the accident was loss of control in flight due to an aerodynamic stall at low altitude.
- The pilot experienced a loss of situational awareness caused by a distraction from a nearby helicopter.
- The approach was unstabilized, characterized by an improper glide path and an abrupt pitch change.
- The pilot failed to execute a go-around maneuver despite the unstable approach parameters.
- The aircraft was attempting to land using an unauthorized portion of the runway threshold.