What happened
On June 22, 2017, an Air Tractor AT 301, registration HK5176, was performing agricultural spraying operations over banana crops in Ciénaga, Magdalena. While cruising at approximately 500 feet above the ground, the aircraft's engine suddenly failed.
The pilot issued an emergency call via the company's internal frequency and immediately identified an unprepared field for an emergency landing. To reach the selected site, the pilot executed a 36able 360-degree descending turn to the left. During the final segment of this maneuver, the left wing struck a palm tree, causing a loss of control that sent the aircraft into the terrain.
Upon impact, the engine and propeller detached from the engine mount. The rupture of fuel lines ignited a post-crash fire that consumed approximately 90% of the aircraft. Although the pilot managed to evacuate the wreckage on his own, he sustained severe burns and passed away several days later.
The investigation
The GRIAA investigation examined the aircraft's maintenance history, the engine's condition, and the flight sequence. The investigation confirmed that the pilot was fully qualified, with over 12,000 flight hours, and held a valid medical certificate. The aircraft was found to be airworthy, with all required maintenance services up to date.
Investigators analyzed the engine, a Pratt & Whitney R-1340-AN 1, which had recently undergone a major overhaul in the United States. While the engine showed no signs of prior improper maintenance, the intense post-crash fire destroyed critical components, including the carburetor, magnetos, and fuel system, making it impossible to pinpoint the exact mechanical trigger for the failure.
Findings
- The primary cause of the accident was a forced landing in an unprepared field resulting from an engine failure during low-altitude flight.
- The pilot's decision to execute a 360-degree descending turn to reach the landing site likely contributed to the collision with the palm tree.
- The engine failure itself could not be definitively determined due to the destruction of key components by fire.
- The post-crash fire was triggered by broken fuel lines making contact with hot exhaust components or electrical sparks.
- The aircraft struck the ground at a low angle and low speed, but the impact with vegetation caused the loss of control.