What happened
On September 16, 2015, an Air Tractor AT-802 "Fire Boss" Amphibious, registration I-SPEV, was engaged in aerial firefighting operations near Volturara Appula, Italy. While performing an attack on a wildfire front, the pilot lost visual contact with the flames due to heavy smoke and decided to abort the mission.
To execute an escape maneuver, the pilot entered a valley. During this phase, the aircraft began to lose energy. In an attempt to maintain flight, the pilot performed an emergency release of the water payload. However, the aircraft was unable to maintain sufficient altitude or airspeed. The pilot attempted an emergency landing in an open field, but the aircraft entered a stall, causing the right wing to strike the ground first, followed by a roll that brought the engine and propeller into contact with the terrain. The aircraft was destroyed, though the pilot sustained non-serious injuries.
The investigation
The ANSV investigation examined the aircraft's performance, the environmental conditions, and the pilot's actions. Investigators analyzed the terrain, noting that the valley used for the escape route had an ascending profile that was not correctly identified during the initial reconnaissance flights.
Meteorological data revealed strong winds (up to 30 knots) coming from behind the aircraft (tailwind) and high ambient temperatures, likely exacerbated by heat from the nearby fires. The investigation also reviewed the aircraft's maintenance records, which were up to date, and the pilot's flight experience, noting his extensive background as an instructor on this type.
Findings
- The primary cause of the accident was the loss of aerodynamic control during the escape maneuver.
- A significant tailwind and high temperatures reduced the aircraft's performance and airspeed.
- The pilot's escape route followed a valley with an upward-sloping terrain that had been misperceived as flat during reconnaissance.
- The high angle of attack required to maintain separation from the ground increased drag, further depleting the aircraft's kinetic energy.
- The aircraft was operating at a high weight (approximately 15,500 lbs) before the emergency release, which limited the maximum rate of climb.