Introduction
On July 2, 2022, about 1733 Pacific daylight time, an Air Tractor AT-602, registration N602GH, was substantially damaged when it was involved in an accident near Lind, Washington. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 137 aerial application flight.
Sequence of Events
According to a witness, about 1717 the pilot departed his hangar after refueling and re-loading the hopper for an aerial application flight. GPS data revealed that the pilot was applying pesticide in a west-to-east racetrack pattern. While maneuvering at a low altitude over an open field about 1733, the airplane impacted terrain.
Surveillance video footage from a building about 1 nautical mile southwest of the accident site showed the airplane flying wings level and transitioning into a steep right turn. About seven seconds later, the airplane entered a nose-down, right-wing-low descent and then disappeared behind a knoll. Shortly after, a plume of dust appeared in the video.
Impact and Wreckage
The airplane impacted a dirt field about 4.5 nautical miles east of the hangar at an elevation of about 1,883 ft mean sea level. The wreckage debris path was about 190 ft long and oriented on a magnetic heading of about 155°. The airplane came to rest upright after sliding upslope.
The first point of impact was an impression consistent with the left tire, followed by the left wing and belly. The impression contained the left landing gear and fragmented pieces of fiberglass and fuselage. Ground scars and damage were consistent with a flat, shallow, left-wing-low impact attitude. No post-impact fire occurred, but an odor consistent with Jet A fuel was present. All major components were within the debris field.
Cockpit and forward fuselage sustained impact damage, including the windscreen. The instrument panel showed forward buckling and compression damage; multiple gauges were displaced. The power lever, condition lever, and propeller lever were each found in the full forward position. Flight control continuity was established from the cockpit to the elevator, rudder, and aileron controls. The wings remained attached with skin buckling. The left flap and aileron separated and came to rest forward of the cockpit; the right flap and aileron partially remained attached. Both flaps and ailerons sustained impact damage. The empennage partially separated and came to rest vertically on the rudder. Leading edges of both elevators and trailing edge of the rudder sustained compression damage.
Engine Examination
The engine, a Pratt & Whitney PT6A-65AG, remained attached to its mounts. The reduction gearbox separated at the “A” flange. Internal engine damage was consistent with developing power at impact; damage throughout the second stage carrier slots was consistent with producing power. The engine was equipped with a five-bladed, reversible Hartzell propeller. The hub and blade assembly separated from the reduction gearbox at the propeller flange. The second stage carrier No. 5 bearing journal was fractured consistent with tension overload. Each blade remained attached to the hub; damage was consistent with the engine operating within a high-power range at the time of the accident.
Examination of the airframe and engine revealed no evidence of any mechanical malfunctions or anomalies that would have precluded normal operation.