What happened
On July 25, 2022, a Eurocopter AS-350-B3, registration EC-NTE, was engaged in a firefighting mission near Cerezo de Mohernando, Spain. The aircraft, operated by Pegasus Aviación, was performing water drops using a helibucket to combat a large forest fire. During an exit maneuver following a water drop, the helicopter's main rotor blades struck high-voltage power lines.
The impact caused an unrecoverable loss of engine power. The pilot attempted an emergency landing on a steep slope, but the aircraft's skid made contact with the uneven terrain, causing the helicopter to overturn. A post-impact fire broke out, completely destroying the aircraft. The pilot, who sustained minor injuries, managed to shut off the fuel valve and battery to escape the wreckage before the fire spread.
The investigation
The CIAIAC investigation examined the aircraft's maintenance records, the pilot's training, and the environmental conditions at the time of the accident. The investigation confirmed that the AS-305-B3 was airworthy, within weight limits, and that all mechanical systems were functioning correctly prior to the strike. The pilot was found to be fully qualified and compliant with all required training and rest periods.
Investigators analyzed the flight path and the visibility conditions, noting that the presence of heavy smoke from the wildfire and the lack of visible markings on the power line pylons significantly hindered the pilot's ability to identify the obstacle.
Findings
- The primary cause of the accident was the performance of low-altitude flight during a firefighting operation in an environment with reduced operational safety conditions, resulting in the main rotor blades striking a high-voltage power line.
- The collision occurred because the pilot inadvertently failed to follow safety procedures regarding water drops near high-voltage lines.
- Reduced visibility due to wildfire smoke and the camouflage effect of the power lines against the terrain acted as contributing factors.
- The pilot's focus on the water drop location, combined with the high workload and fatigue at the end of a demanding mission, likely led to a loss of situational awareness.