What happened
On October 7, 2017, an Air Tractor AT-301, registration HK5085, was conducting aerial spraying operations over the Cibeles plot in Turbo, Antioquia, Colombia. After completing six spraying passes, the pilot attempted to perform a "rebordeo" (perimeter pass) around the field. During this maneuver, the pilot noted that the aircraft was losing power, speed, and altitude. The engine eventually failed completely.
The pilot declared an emergency and managed to execute a controlled emergency landing in a banana plantation at the La Saya farm. Upon initial contact with the uneven terrain, the nose wheel sank into soft ground, causing the aircraft to pivot sharply and come to rest in an inverted position. The pilot, who was uninjured, was able to exit the aircraft through the cockpit window and confirmed there was no fire. The aircraft sustained substantial damage to its structure, engine, propeller, and wings.
The investigation
The GRIAA investigation established that the aircraft had been fueled with 50 gallons of fuel the previous day, despite the mission requiring a minimum of 58 gallons. The investigation found that the pilot was unaware of the exact fuel quantity on board and had not verified the tanks during the pre-flight inspection. Furthermore, the pilot mistakenly believed the aircraft had a higher fuel capacity, likely confusing it with a Cessna 188.
Investigators also noted a lack of formal flight planning by both the pilot and the dispatch office. There were no established procedures within the operator, FUMIGARAY S.A.S., to calculate the required fuel based on flight distance, spraying duration, and necessary reserves for returning to base or reaching alternate airports.
Findings
- Fuel exhaustion and subsequent engine shutdown caused by inadequate flight planning and a deficient pre-flight inspection by both the pilot and dispatch.
- The pilot's decision to continue flight maneuvers despite the fuel indicator showing only five gallons remaining.
- A lack of operational procedures within the company to ensure appropriate refueling based on mission requirements.
- The absence of a standardized method for calculating minimum fuel requirements for agricultural spraying operations.