What happened
On January 1, 2002, a Canadair CL 415, registration I-DPCN, was engaged in aerial firefighting operations to suppress a forest fire in a valley east of Pietra Ligure, Italy. During the mission, the crew had completed four successful water drops. However, following feedback from ground personnel that wind conditions were drifting the water away from the fire line, the crew adjusted their flight path closer to an electrical power line installation.
During the fifth pass, as the aircraft began a turning maneuver following the water release, the left wingtip struck an unmarked ground wire belonging to the southernmost line of the power installation. The impact caused approximately three-quarters of the left winglet to be severed. The detached structural component fell into a private garden, though no injuries or ground damage were reported. The crew immediately ceased firefighting operations, verified the aircraft's controllability, and returned to Rome Ciampino Airport, landing without further incident.
The investigation
The ANSV investigation examined the aircraft's structural integrity, the flight dynamics, and the environmental conditions at the time of the event. Technical analysis of the winglet fracture revealed that the impact occurred at a low speed (approximately 120 knots). The ground wire acted as a buffer, stretching progressively and creating a tearing action rather than a clean cut, which eventually lacerated the winglet structure.
Investigators also reviewed flight footage from an amateur video, which helped reconstruct the flight path and altitude (approximately 150 feet). The investigation noted that while the northernmost line of the power installation featured high-visibility marker spheres, the southern line was unmarked. Furthermore, the investigation considered the impact of environmental factors, including heavy smoke from the fire and intense sunlight, which created challenging visual conditions for the crew.