What happened
On July 25, 2005, a Robinson R44 Raven II, registration I-NEVY, was performing a visual flight rules (VFR) flight for tourism purposes. The pilot was flying from a temporary helisurface in Velletri to a private landing site located on his own property in the Colle degli zingari area of Olevano Romano.
As the pilot approached the landing area, the tail rotor struck a protruding bush. This impact caused the immediate failure of the tail rotor and the horizontal stabilizers. The resulting loss of directional control triggered a violent pitching motion and a "whip effect" in the main rotor. As the aircraft began to spin, the main rotor blades struck the tail boom, severing it. The helicopter lost altitude rapidly and impacted the ground, resting on its left side. The pilot, who was the sole occupant, was able to exit the aircraft independently and sustained only minor abrasions.
The investigation
The ANSV investigation examined the wreckage and the flight circumstances. Investigators found that the tail boom had been cleanly severed, with yellow paint transfers visible on the broken section. Broken branches from a nearby bush were found with blue and red paint traces, matching the aircraft's stabilizers. The investigation also noted that the pilot frequently used this specific landing site but typically approached from the opposite direction, which placed the bush behind the aircraft rather than in the path of the approach.
Technical analysis confirmed that the Robinson R44 Raven II was in a good state of airworthiness, with all maintenance inspections up to date. The investigation also ruled out engine power loss, as the aircraft remained efficient until the moment of the rotor strike.
Findings
- The primary cause of the accident was the incorrect approach trajectory chosen by the pilot, which failed to account for the presence of the protruding bush.
- A contributing factor was the position of the sun, which was directly in front and slightly to the left of the pilot during the approach, potentially causing glare and making the obstacle harder to detect.
- The pilot's familiarity with the site may have led to a lack of vigilance, as previous approaches from the opposite direction had not presented this obstacle as a threat.