What happened
On August 12, 2010, at approximately 06:20 UTC, a Robinson R44 II helicopter, registration I-KOST, was performing a takeoff from a paved area in front of an industrial warehouse near Pace del Mela, Sicily. The flight was intended to transport the pilot and three passengers to the island of Salina.
Immediately after liftoff, while only a few meters above the ground, the aircraft's main rotor blades struck the northeast corner of the industrial building. The impact caused the helicopter to crash and subsequently burst into flames. The intense fire completely destroyed the cockpit. The tail boom and tail rotor remained largely intact, separated from the main wreckage. The accident resulted in 4 fatalities, including the pilot.
The investigation
The ANSV investigation examined the aircraft's weight, the environmental conditions, and the aerodynamic phenomena present at the time of the accident. Investigators noted that the takeoff area was an improvised helipad that had been used previously but had not been specifically reported for this particular flight. The site was located near hazardous materials, including a large mobile fuel dispenser and a LPG storage tank.
Investigators analyzed the aircraft's weight and balance, estimating a takeoff weight of approximately 2,584 lbs. The investigation also looked into the pilot's experience and the meteorological conditions, which were generally favorable, though the sun was low on the horizon, potentially affecting visibility.
Findings
- The primary cause of the accident was the impact of the main rotor blades against the industrial structure, which was attributable to inadequate takeoff management and improper flight planning by the pilot.
- The aircraft's weight and center of gravity, combined with high ambient temperatures, likely hindered the pilot's ability to execute the takeoff using previously established methods.
- An aerodynamic phenomenon known as "recirculation" likely occurred as the helicopter flew near the building in ground effect. This caused an asymmetric loss of lift, creating a tendency for the aircraft to drift toward the obstacle.
- The low position of the sun may have caused momentary glare, impairing the pilot's ability to perceive the distance to nearby obstacles.
- Wind conditions from the rear sectors of the helicopter may have further reduced lift.
- Operational pressure to complete the passenger transfer may have negatively influenced the pilot's decision-making regarding weight and balance limitations.