What happened
On April 2, 2011, a Pilatus PC-6/B2-H4, registration D-FATA, was performing its seventh skydiving flight of the day near Ravenna, Italy. Shortly after departing from runway 08, the pilot experienced a malfunction in the propulsion system. At a low altitude, the aircraft entered a left-hand turn in an attempt to return to the runway or find a suitable landing area away from nearby obstacles. During this maneuver, the aircraft lost altitude and entered an asymmetric stall. The aircraft impacted a cultivated field approximately 380 meters north of the airport, resulting in the destruction of the aircraft and causing 11 injuries, some of which were serious.
The investigation
The ANSV investigation focused on the engine's performance, the aircraft's weight and balance, and the flight maneuvers. Investigators examined the wreckage and found that while the engine likely continued to produce some power, it was insufficient to maintain flight during the turn. The investigation also reviewed the aircraft's configuration, noting that it had been modified with non-original seating and equipment for skydiving operations.
Regarding the occupants, investigators found that although seatbelts were installed and available, the skydivers were not wearing them. The investigation noted that it was common practice for passengers on this aircraft to forgo the use of seatbel ts during flights. The investigation also looked into the pilot's takeoff technique, noting that power was applied gradually rather than at maximum setting during the takeoff roll.
Findings
- The primary cause of the accident was the loss of control in flight following an aerodynamic stall.
- This stall was triggered by an engine malfunction, characterized by a probable loss of power, which occurred during a low-altitude turn.
- Contributing factors included an aft center of gravity (CG) position, which increased the aircraft's susceptibility to instability.
- The pilot's technique of applying power gradually during the takeoff roll may have negatively impacted performance during the critical climb phase.
- The severity of the injuries to the occupants was likely aggravated by the fact that the passengers were not wearing their seatbelts, leading to violent impacts within the cabin during the crash.