What happened
On February 27, 2022, at approximately 14:50 UTC, an EC 120 B helicopter, registration PH-OMM, was performing a recreational flight near the "Cassina Rizzardi" helipad in Fino Mornasco, Italy. The flight was the second of the day, following a previous leg that had been diverted due to the pilot's inability to locate a different landing site.
As the pilot approached the helipad, the aircraft was at a low altitude, roughly 20 to 30 meters above the surrounding structures. During the final positioning phase, the helicopter began an unexpected rotation to the right. The pilot attempted to manage the descent by reducing collective pitch and directed the aircraft toward the nearby A9 motorway embankment to find a level surface. During the subsequent impact, the aircraft struck a roadside wall, causing the tail to detach and the main rotor to disintegrate. The helicopter came to rest on its right side on the motorway. The pilot sustained serious injuries, while the passenger suffered minor injuries.
The investigation
The ANSV investigation examined the wreckage, meteorological data, and witness statements. Investigators found no evidence of mechanical failure in the engine, transmission, or flight control linkages. While the pilot suggested a potential issue with the pedal linkage, the investigation found the flight controls to be functional and the hydraulic cutoff switch remained in the closed position, suggesting no hydraulic failure occurred.
Meteorological reports from Milan Malpensa indicated excellent visibility and calm winds, ruling out environmental factors. Analysis of the rotation direction was also critical; investigators noted that a Loss of Tail Rotor Effectiveness (LTE) would have caused a leftward rotation due to the clockwise rotation of the main rotor. However, both the crew and witnesses reported a rightward rotation, suggesting the movement was likely caused by pilot input rather than an aerodynamic phenomenon like LTE.
Findings
- The primary cause of the accident was a loss of control in flight during the low-altitude landing approach.
- The pilot's significant flight experience was largely based on the NH500, an aircraft with different handling characteristics and a non-fenestron tail rotor. The limited experience on the specific aircraft type (the EC 120 B) likely contributed to the event, as the pilot may have struggled with the different feedback and torque compensation required by the fenestron system.
- It is possible that an excessive application of right pedal was not properly compensated for with left pedal input, triggering the uncontrolled rotation.