What happened
On December 16, 2006, an Eurocopter AS 350 B2, registration EC-FOQ, was conducting a traffic surveillance mission near La Seo d’Urgell, Lleida. The aircraft, operated by TAF Helicopters on behalf of the Generalitat de Catalunya, was flying at altitudes of 300 ft AGL or higher to monitor road traffic.
During the flight, the crew identified a vehicle committing a traffic violation. To identify the vehicle's license plate, the pilot initiated a descent to approximately 100 ft AGL. During this maneuver, the helicopter struck three aluminum alloy power cables that crossed the flight path perpendicularly. The impact caused significant damage to the nose, including a broken pitot tube and a destroyed windshield, and the cables became entangled in the main rotor components. Despite the destabilization, the pilot successfully regained control and performed an emergency landing on the roadway. One passenger sustained minor injuries.
The investigation
The investigation examined the aircraft's equipment, the pilot's training, and the operational environment. It was established that the aircraft lacked wire cutters or enhanced vision/recording equipment to identify vehicles from a distance. Furthermore, the investigation found that the pilot had not received specific training for low-altitude flight operations, and the crew members had not received specialized training for these specific mission tasks. The investigation also noted that the power lines crossing the road lacked any visual markers or aviation warning lights.
Findings
- The lack of long-range identification equipment forced the pilot to descend to dangerous altitudes to visually identify vehicle plates.
- The absence of specific low-altitude flight training for the pilot contributed to the risk during the pursuit maneuver.
- The lack of marking or signaling on the power lines prevented timely detection of the obstacle.
- The aircraft was not equipped with wire-cutting systems or tools to mitigate the effects of such impacts.