What happened
On July 5, 2009, a Piper PA-18-150, registration D-ELHP, crashed near Dro in the Trentino region of Italy. The aircraft, carrying two Italian pilots, had departed from Trento Mattarello airport earlier that morning to participate in an aerial demonstration known as "Ali sul Lago di Cavedine" at Lake Cavedine. The aircraft was reportedly flying in support of the event, likely acting as a photography platform.
Shortly before the accident, the pilot passenger communicated via radio to the event operator, stating an intention to perform a low pass over the area. However, eyewitnesses observed the aircraft performing a sharp left-hand turn. During this maneuver, the aircraft's attitude changed abruptly, leading it to strike treetops and impact the ground at a steep angle of approximately 60 to 70 degrees. Both occupants sustained fatal injuries due to the high-velocity impact.
The investigation
The ANSV investigation examined the aircraft's technical condition, meteorological data, and the physical evidence at the crash site. Technical inspections of the Lycoming engine and the aircraft's airframe showed no signs of mechanical failure or structural disintegration in flight. The investigation also reviewed the medical findings from the autopsy, which noted that the pilot suffered from a chronic lung condition and the passenger from a cardiovascular condition, though it could not definitively confirm if a sudden medical emergency triggered the event.
Meteorological analysis, supported by testimony from a nearby helicopter pilot, indicated favorable flying conditions with a steady southern breeze (the "Ora del 15-20 knots") and no significant turbulence or microclimatic disturbances that could have caused a loss of control.
Findings
- The investigation identified the primary cause as a loss of control triggered by an accelerated stall during a turn, which led to an entry into autorotation. The low altitude at the time of the maneuver prevented the crew from recovering the aircraft.
- The investigation considered two possible scenarios for the steep turn: an intentional maneuver to capture photographs, which may have resulted in an asymmetric stall, or an unintentional maneuver caused by a sudden loss of consciousness of the pilot in command.
- There was no evidence of weight or center-of-gravity exceedances, nor any evidence of engine malfunction or maintenance-related issues.