What happened
On June 25, 2011, at approximately 08:00 UTC, a Schweizer S269C helicopter, registration I-LIAO, was performing aerial work in the Rolle area of Cison di Valmarino, Italy. The aircraft was engaged in a crop-spraying mission over a hilly landscape characterized by terraced vineyards. During the operation, the helicopter struck a guard wire belonging to an electrical power line crossing the valley. The impact caused the aircraft to crash into the ground, resulting in the destruction of the aircraft and the death of the pilot.
The investigation
The ANSV investigation focused on the circumstances surrounding the collision and the operational environment. Investigators examined the wreckage and the site, noting the presence of the electrical infrastructure and the frayed state of the guard wire. The investigation confirmed that the pilot had been operating in this specific work area for approximately ten days prior to the accident. Technical inspections of the aircraft and its Lycoming HIO-360-D1A engine were conducted, and no mechanical or technical failures were identified as contributing to the crash.
Findings
- The primary cause of the accident was the collision with an electrical guard wire.
- The aircraft was operating in a hilly region with elevations between 250 and 300 meters.
- Meteorological conditions at the time of the event featured excellent visibility.
- There were no identified technical malfunctions regarding the helicopter's airworthiness or engine performance.
- The investigation noted that while the pilot was familiar with the operational area, the safety of the mission remains subject to further evaluation regarding human factors and the adequacy of the operator's standard operating procedures (SOPs).