What happened
On October 25, 2010, at approximately 10:00 local time, a Bell 206-BII helicopter, registration EC-DXZ, was performing agricultural spraying operations over a lettuce farm near Pozo de la Higuera, Lorca. The pilot had previously conducted an aerial reconnaissance of the area, identifying two electrical lines sharing a common pole and noting calm wind conditions. The initial flight strategy involved flying east-to-west and west-to-east along the field furrows at an altitude of approximately two meters, planning to pass underneath the identified power lines.
After 15 minutes of operation, the pilot decided to alter the established flight pattern due to interference caused by a utility pole and a tractor parked on a farm path. While initiating a right turn and an ascent to reposition for the new flight path, the pilot attempted to fly under power cables that appeared ahead. The main rotor mast struck a cable, causing the helicopter to crash and overturn on its right side. The pilot, who was uninjured, successfully shut down the engine and electrical power before exiting the aircraft.
The investigation
The CIAIAC investigation focused on the sequence of maneuvers and the aircraft's interaction with the electrical infrastructure. The investigation established that the aircraft, operated by Heliswiss Ibérica, S. A., was equipped with a Simplex Model 4900 Spray System and was maintained according to the approved program. The aircraft lacked any specialized wire-strike protection systems.
Investigators examined the pilot's decision-making process during the transition between flight strategies. The analysis noted that while the pilot was highly experienced in agricultural spraying and was familiar with the specific farm from previous seasons, the impact occurred precisely during the execution of a change in the flight plan.
Findings
- The main rotor mast was severed, and the main rotor assembly became separated from the helicopter structure.
- The aircraft sustained important damage to the rotor mast, tail rotor assembly, landing gear, and spraying equipment, while also causing damage to the electrical line.
- The primary cause of the accident was the impact with the power line during a maneuver intended to change the flight pattern.
- The pilot's decision to alter the flight path without re-evaluating the risks associated with the known electrical lines contributed to the collision.