What happened
On August 9, 2019, at approximately 12:30 UTC, a Flycajn amphibious helicopter, registration I-D347, crashed into the ridge of Monte Rua near Preturo, Italy. The aircraft, which was being operated for recreational flight, was piloted by a single individual.
The pilot had departed from the Sangermano ACLI airfield near Cerveteri/Palidoro, heading toward Val Vibrata. While flying over the mountains near San Marco di Preturo at an altitude of approximately 5,500 to 6,000 feet, the pilot experienced a loss of control, resulting in a left-hand rotation and a loss of altitude. Although the pilot managed to briefly regain control and enter a hover near the mountainside, the tail rotor subsequently struck an obstacle, likely a tree. This impact triggered an uncontrolled leftward rotation, leading the main rotor blades to strike the mountain ridge, which caused the aircraft to overturn and be destroyed. The pilot escaped the wreckage without injury.
The investigation
The ANSV investigation revealed several discrepancies regarding the aircraft's configuration and documentation. Although the I-D347 was an amateur-built aircraft based on the Robinson R22 design, investigators found that the wreckage differed significantly from the technical documents filed with the Aero Club d’Italia. Specifically, the aircraft featured doors and analog instruments, whereas the documentation specified it should have been doorless and equipped with digital instruments. Additionally, the floats were not installed.
Investigators also raised concerns regarding the aircraft's weight and balance. The declared empty weight was based on a weighing procedure using a scale that had an expired calibration certificate and a maximum capacity lower than the recorded weight. Furthermore, evidence suggested the use of two different scales during the weighing process, which was not documented. Because of these discrepancies, the exact performance capabilities and the center of gravity of the aircraft on the day of the accident could not be determined.
Findings
- The primary cause of the accident was inadequate flight planning and execution in high-density altitude conditions near mountainous terrain.
- The pilot had limited experience, having obtained their rotary-wing recreational license only a few months prior to the event.
- The aircraft's configuration differed from its registered technical specifications.
- There was a lack of a specific flight manual tailored to the unique modifications of this amateur-built aircraft.
- Uncertainties regarding the aircraft's actual empty weight and center of gravity contributed to the reduced safety margins.