What happened
On July 11, 2023, a Piper PA 25-260, registration HK370, was performing agricultural spraying operations over rice crops at the Flor Amarillo farm in Villanueva, Casanare. After completing an initial mission, the pilot departed from the Santa Clara airstrip to conduct a new spraying pass over an 18-hectare plot.
During the first pass, the pilot noticed engine vibrations and a lack of performance. Although the pilot immediately released the chemical payload and attempted to gain altitude while checking the instruments, the engine began to lose power. Seeking an emergency landing site, the pilot identified an unprepared field. As the aircraft leveled out for touchdown, it struck a fence, which caused a dynamic rollover, leaving the aircraft inverted on the ground. The pilot was able to evacuate the aircraft uninjured, though a post-crash fire consumed approximately 90% of the airframe.
The investigation
The investigation conducted by the DIACC focused on the mechanical failure of the engine and the maintenance status of the aircraft. Investigators examined the fuel system and the carburetor, specifically looking for evidence of component failure. The analysis also reviewed the pilot's training, the aircraft's maintenance records, and the operator's compliance with regulatory requirements.
Findings
- The primary cause of the accident was the collision with a fence during an emergency landing necessitated by engine power loss.
- The engine power loss was caused by a failure in the fuel injection system, resulting from a deformed spring in the carburetor discharge check valve.
- The operator had failed to comply with Service Bulletin SB-8 (issued December 13, 2010), which mandates the inspection of this specific valve spring to prevent malfunctions.
- A significant contributing factor was that the aircraft was operating without a valid Certificate of Airworthiness, as the documentation was pending due to an ongoing change of ownership.
- No evidence of pilot error, fatigue, or impairment was found, and the aircraft was within its weight and balance limits at the time of the event.