What happened
On August 12, 2001, a private flight involving an Eurocopter EC 120B, registration I-TECH, resulted in an accident in the vicinity of Todi, Italy. The pilot was performing a local flight, using a private garden as a temporary helipad. While maintaining a hover at approximately 1.5 meters above the ground, the pilot attempted to rotate the aircraft to the left to transition from a tailwind to a headwind condition.
During this maneuver, the helicopter began an uncontrolled and accelerating rotation around its vertical axis. The aircraft completed three full rotations before striking an olive tree and a hedge, eventually impacting the ground on a dirt road. The pilot successfully shut down the engine and exited the aircraft without injury. The impact caused significant damage to the aircraft's main rotor blades, tail boom, and engine components, as well as damage to local vegetation.
The investigation
The ANSV investigation focused on the mechanical integrity of the tail rotor and the pilot's handling of the aircraft. Technical inspections of the tail rotor control system, including the pedals, linkages, and tail rotor blade incidence angles, revealed no mechanical failures or obstructions. The controls were found to be functioning according to the manufacturer's specifications.
Investigators also reviewed Eurocopter Service Letter No. 1518-67-01, issued in April 2001. This document addressed a known phenomenon regarding "YAW control" in certain flight configurations, such as low-altitude hovering. The letter warned that initiating a left turn in these conditions could induce a high rate of rotation, requiring the pilot to apply immediate and sustained right pedal input to stabilize the aircraft. The pilot stated he was unaware of this specific Service Letter.
Findings
- The primary cause of the accident was the suboptimal execution of the left-hand rotation maneuver by the pilot during a low-altitude hover.
- The pilot's failure to maintain sufficient right pedal input—or a delay in applying it—allowed the uncontrolled rotation to escalate.
- The pilot's limited experience on the specific aircraft type contributed to the event, as he had not yet completed the formal type-rating certification.
- The low altitude of the hover and the close proximity of fixed obstacles, such as the olive tree, left no margin for error once the rotation became uncontrolled.