What happened
On February 24, 2021, at approximately 16:30 local time, an Air Tractor AT802, registration EC-MNF, was engaged in aerial firefighting operations near Nueva Imperial, Chile. The aircraft was operating in a formation with another aircraft to suppress a forest fire. Prior to the mission, the crew had been alerted by communications dispatch regarding the presence of low-altitude cables in the area.
In an attempt to identify these hazards, the pilots performed five reconnaissance passes over the fire site. Despite these efforts, the cables remained undetected. During the suppression run, the pilot positioned the aircraft as the lead element to discharge water. While flying at an altitude of approximately 12 meters, the aircraft struck a steel cable used for forest extraction operations. The impact caused the propeller to detach from the engine, resulting in a total loss of thrust and directional control. The aircraft subsequently struck trees in a native forest, where it became suspended. The pilot survived the impact without injuries.
The investigation
DGAC Chile investigators examined the wreckage, the aircraft's maintenance records, and the flight crew's actions. The investigation confirmed that the aircraft's maintenance was up to date, with the last inspection completed only days before the accident. The engine and propeller components showed clear evidence of the impact with the steel cable.
Investigators also analyzed the site of the impact and the subsequent crash location. The steel cables, which were part of a forestry work tower, were found to be unlit and unmarked, with heights ranging between 10 and 15 meters. The investigation also reviewed the operator's manual, which mandates a minimum release altitude of 50 feet (approximately 15.24 meters) above the terrain.
Findings
- The primary cause of the accident was the impact of the aircraft with a steel cable, which led to the propeller detaching and subsequent loss of control.
- The pilot made the decision to proceed with the water drop despite having uncertainty regarding the exact location of the reported cables.
- The aircraft was operating at an altitude of approximately 12 meters, which was below the minimum release height of 15.24 meters specified in the operator's manual.
- The forestry cables lacked any visible signaling or markings to alert low-flying aircraft to their presence.
- The aircraft's mechanical systems and maintenance status were not contributing factors to the accident.