What happened
On December 27, 2004, a Bell 206B helicopter, registration EC-GNQ, was performing agricultural spraying operations in the municipality of Las Herrerías, Almería. The aircraft was conducting a second pass of the morning over a lettuce field, flying at a speed of approximately 40 knots and maintaining an altitude of 1.5 meters above the ground.
The flight path required the pilot to navigate around an electrical power line installation with poles spaced roughly 150 meters apart. As the aircraft approached the power lines, the pilot initiated a descent to approximately 1 meter above the ground to ensure clearance under the lowest point of the wires. During this maneuver, the left skid made contact with the ground, causing the aircraft to lose stability. The right skid subsequently struck the terrain, and the helicopter immediately overturned, sliding on its left side. The impact resulted in the destruction of the aircraft.
The investigation
The investigation examined the flight path, the aircraft's configuration, and the pilot's actions. It was noted that the aircraft was equipped with a specialized spraying system certified by the FAA. Investigators analyzed the ground tracks, which showed a 20-meter path starting with the left skid and ending with the right skid. The investigation also reviewed the pilot's statement regarding the flight conditions and the specific challenges posed by the electrical infrastructure.
Findings
- The primary cause of the accident was an excessive descent while approaching the electrical lines.
- The pilot's attention was diverted toward maintaining clearance from the power cables, specifically at the midpoint of the span where the cable sag is greatest, leading to a neglect of the altitude relative to the ground.
- The contact of the left skid with the terrain caused an immediate loss of control that could not be recovered at the operating speed of 40 knots.
- The pilot remained uninjured and was able to evacuate the aircraft independently.