What happened
On February 21, 2002, a Robinson R44 helicopter, registration N110DD, crashed in the Paladon area of San Pietro in Cariano, Italy. The flight originated from a helipad in Costermano del Garda, with the pilot intending to fly to Villa dal Quar before continuing to a second destination near Ronchi dei Legionari.
During the first leg of the flight, the pilot communicated with Garda APP to coordinate flight plans. However, at approximately 07:42 UTC, the aircraft impacted the ground in a vineyard and subsequently caught fire, resulting in the total destruction of the aircraft. There were no fatalities reported.
The investigation
The ANSV investigation focused on the aircraft's condition, the pilot's credentials, and the environmental factors at the time of the accident. The investigation established that the engine and the overall mechanical state of the aircraft were in good condition and suitable for the intended flight. The pilot held valid licenses for both R22 and R44 models and was medically fit to fly.
Analysis of the wreckage revealed significant structural damage, including a deformed main rotor shaft and broken control linkages. The distribution of the debris and the skid marks on the ground indicated that the aircraft struck the terrain with a low forward airspeed but a high, uncontrolled rate of descent.
Findings
Several critical factors contributed to the accident:
- Reduced visibility: Heavy fog was present in the area, significantly limiting visual references. Witnesses and an arriving rescue helicopter confirmed that visibility was extremely poor, with some observers reporting "zero visibility."
- Loss of control: The investigation identified two probable scenarios. The first is that the pilot became disoriented due to the loss of external visual references while descending through the fog. The second, and more likely, scenario is that the pilot reduced forward airspeed too much during the descent, triggering a vortex ring state.
- Operational limitations: The pilot was operating under Visual Flight Rules (VFR) and was not rated for Instrument Flight Rules (IFR), making the flight highly susceptible to the dangers of low-visibility environments.