Accident Overview
An airplane conducting aerial firefighting operations crashed after striking trees during a retardant drop. According to witnesses, the aircraft had completed a dry pass over the fire zone before circling for a second pass. During the second pass, while releasing its load of 2,450 gallons of retardant, the airplane impacted trees in a nose-low, right-wing-low attitude. Upon ground impact, the aircraft exploded and burned.
Investigation Findings
Investigators found no evidence of preimpact failure or malfunction involving the airframe, engines, propellers, or flight controls. The cockpit configuration placed the first officer, an initial attack trainee pilot, in the left seat, while the captain occupied the right seat.
Toxicology Results
Toxicology tests performed on the first officer detected substances in kidney and liver fluids: 0.031 µg/ml brompheniramine and 0.011 µg/ml chlorpheniramine in kidney fluid, and 0.142 µg/ml brompheniramine and 0.072 µg/ml chlorpheniramine in liver fluid. Both medications are over-the-counter antihistamines known to have sedative effects.