What happened
On June 5, 2021, at approximately 07:20 local time, a PIPER PA-36-285, registration EC-HUE, was performing agricultural spraying operations over rice fields near Isla Mayor, Seville. After completing the treatment of a plot, the pilot began the return flight toward a temporary landing strip located at Puente de los Alemanes.
During this transit, the pilot observed power lines ahead. In an attempt to avoid the obstacle, the pilot maneuvered the aircraft to fly underneath the cables, believing this would prevent the landing gear from snagging. However, the aircraft's tail section struck the electrical lines. The impact was severe enough to sever the vertical stabilizer and the rudder from the airframe. The aircraft's specialized cable-cutting device was also partially destroyed.
Following the impact, the aircraft experienced significant instability and a sharp yaw. The pilot managed to perform an emergency landing on a nearby rural road. The pilot sustained minor injuries and was able to exit the aircraft unassisted. The aircraft suffered extensive damage to the tail section, landing gear, engine cowling, propeller, and semi-wings.
The investigation
The CIAIAC investigation examined the flight planning, the aircraft's structural integrity, and the environmental conditions. Investigators noted that the rice fields were flooded, which likely created a "mirror effect" on the water's surface. This optical phenomenon, combined with the low sun angle, likely obscured the pilot's perception of the true altitude and distance to the ground.
The investigation also reviewed the operator's Standard Operating Procedures (SOP). The company's manual requires pilots to prepare for flights by identifying potential hazards, specifically including checking for electrical cable locations. Furthermore, while the operator is authorized to fly below standard minimum altitudes for agricultural work, the manual mandates maintaining a safe altitude to avoid obstacles.
Findings
- The primary cause of the accident was the pilot's failure to adhere to company operational procedures by flying at an altitude that was inadequate for the terrain topography and existing obstacles.
- The pilot's flight planning was insufficient, as the existence of the high-voltage lines was not identified prior to the flight.
- The aircraft was flying at an estimated altitude of only 9 meters above the ground at the moment of impact, which was insufficient to clear the cables safely.
- Environmental factors, including the mirror effect from flooded fields and reduced visibility due to insect impacts on the windshield, contributed to the pilot's difficulty in maintaining situational awareness.