What happened
On April 1, 2012, a Robinson R44 Raven, registration I-SNEK, was involved in an accident at the Air Patria airfield near Lago Patria, Italy. The aircraft had been moved from a hangar to a small mobile platform using a trolley system.
The pilot, who did not initially intend to fly the aircraft, started the engine while the flight controls (cyclic and collective) remained locked in the friction position. During the engine run-up, the pilot noticed the helicopter was shifting toward the left edge of the platform due to vibrations and a southern wind. Fearing the left skid would slide off the platform and cause a rollover, the pilot attempted to lift the aircraft to land on the adjacent grass.
In the process of attempting this unplanned maneuver, the engine RPM rapidly increased to 102%. While the pilot managed to increase the collective, the cyclic remained locked. This caused the helicopter to move uncontrollably toward the north, traveling approximately 40 meters before striking a building's external awning and a perimeter fence. The impact caused the helicopter to be destroyed, and the pilot sustained head injuries and contusions.
The investigation
The ANSV investigation examined the aircraft's configuration, the pilot's actions, and the physical constraints of the takeoff platform. Investigators found that the pilot had failed to follow the "Before Starting Engine" and "Starting Engine and Run-Up" procedures outlined in the Pilot’s Operating Handbook, specifically regarding the disengagement of the cyclic and collective friction locks.
Analysis of the wreckage revealed that while the pilot could manipulate the collective, the cyclic friction knob was found in the "on" position. The investigation also noted that the mobile platform was quite narrow, leaving very little clearance for the left skid, which contributed to the pilot's decision to attempt an immediate lift-off.
Findings
- The primary cause of the accident was the loss of control of the aircraft during an unplanned ascent from a small mobile platform.
- This loss of control was triggered by the pilot's improper management of engine start procedures, as the pilot did not apply the necessary flight control disengagement protocols because they did not intend to fly.
- The pilot's limited experience with the Robinson R44 Raven may have also contributed to the incident.