What happened
During an aerial firefighting mission, an air tanker was tasked with delivering a load of retardant to a fire situated along a valley wall. Following radio communication with ground-based firefighters, the pilot was instructed to release the full payload during the initial pass. To facilitate a safe drop, a nearby helicopter pilot moved to a distance of approximately one mile.
As the air tanker approached the fire from the northeast, it performed a descending counterclockwise turn to align with the valley ridge. At the time, local weather conditions included northwest winds of 15 knots with gusts reaching 20 knots, and the helicopter pilot noted the presence of turbulence. While executing the drop, the aircraft entered a smoke-filled area, at which point the right wing struck trees on the uphill slope of the valley. This impact caused the aircraft to roll 90 degrees, leading to a descent into the steep, heavily forested terrain.
Findings
- The aircraft's right wing made contact with trees during the retardant release.
- Environmental conditions included turbulent winds and low visibility due to smoke.
- The pilot lacked the required color vision certification according to FAA medical records.