What happened
On July 17, 2024, at approximately 15:00 central daylight time, an Air Tractor AT-602, registration N622AW, was involved in an accident near Oakland, Nebraska. The aircraft was being operated by AgWerx Aviation Inc. under Part 137 agricultural flight regulations.
While performing an aerial-application spray turn, the pilot experienced a loss of engine power. The pilot performed a forced landing in a cornfield, which resulted in substantial damage to the aircraft's aft fuselage. The pilot was not injured.
The investigation
An examination of the aircraft's digital engine monitor provided details regarding the fuel state during the flight. Before departure, the aircraft carried approximately 180 gallons of fuel, though an imbalance existed with 105 gallons in the left wing tank and 75 gallons in the right wing tank. While this imbalance narrowed to approximately 10 gallons after departure, a trend developed during the spray passes where fuel decreased from the right wing tank while the left wing tank remained relatively stable. Approximately 1 hour and 4 minutes into the flight, the right wing tank reached zero gallons, and six minutes later, the engine experienced a sudden loss of fuel flow and power.
Data from the engine monitor also showed that during the previous three flights, a fuel imbalance had occurred where quantities fluctuated by at least 10 gallons during spray passes. In those previous instances, fuel levels in the tanks would eventually increase or balance out; however, during this accident flight, the depletion in the right tank continued until exhaustion.
The fuel system on the AT-602 utilizes two 108-gallon wing tanks connected by a 2-gallon header tank. The aircraft lacks a fuel tank selector valve, featuring only a shutoff valve located downstream of the header tank.