What happened
On April 28, 2020, a Robinson R-44 (registration HK5306) was conducting agricultural spraying operations over corn crops at the La Morelia farm in Roldanillo, Valle del Cauca, Colombia. After completing several successful passes, the aircraft was performing its fifth flight of the session when it struck low-voltage electrical cables during a SE-NW pass.
The impact caused the helicopter to lose control and crash into the cornfield, where it overturned on its right side. The collision resulted in the separation of the tail rotor from the structure and significant damage to the landing skids and chemical storage tank. The pilot was able to evacuate the aircraft on his own and sustained no injuries.
The investigation
The GRIAA investigation established that the pilot had performed an initial reconnaissance of obstacles prior to the flight. However, during the fifth pass, the pilot's attention was focused on the cockpit's alignment lights to ensure the correct spray trajectory. This concentration on flight path correction led to a loss of situational awareness regarding external obstacles.
Investigators also noted that the electrical lines were difficult to identify because they were camouflaged by nearby vegetation. Furthermore, the investigation found that while the operator had procedures for hazard identification, there was a lack of active risk management specifically for the mission's unique hazards. The investigation also highlighted that the civil aviation authority lacked specific evaluation criteria for checking the proficiency of pilots specifically engaged in agricultural rotary-wing operations.
Findings
- The primary cause was a low-altitude collision with low-voltage power lines, which were difficult to perceive due to vegetation camouflage.
- The pilot experienced a loss of situational awareness caused by prioritizing cockpit alignment indicators over external obstacle monitoring.
- Organizational deficiencies were identified regarding the identification of hazards and risk management during low-altitude agricultural flights.
- The aircraft was operating within its established flight envelope, and there were no mechanical failures or adverse weather conditions contributing to the accident.