What happened
On August 12, 2023, an Air Tractor AT802A, registration I-SPEB, was engaged in a training flight over Lago Santa Croce, Italy. The flight was part of a training session intended to maintain pilot proficiency during a period of low firefighting activity. Following a landing on the lake, the pilot attempted a subsequent takeoff. However, the aircraft failed to accelerate as expected due to excessive aerodynamic drag.
In response to the lack of performance, the pilot decided to abruptly abort the takeoff. This sudden interruption caused the aircraft to pitch forward violently. The resulting nose-down attitude led to the propeller striking the water surface, causing substantial damage to the propeller blades, the engine mount, the ventral fin, and the accessory gearbox.
The investigation
The ANSV investigation established that the aircraft had been pre-configured for a "scooping" maneuver, which involves extending scoops to collect water via hydrodynamic pressure. Although the pilot had originally intended to perform a "fast float" maneuver instead, the water scooping system remained extended and the hopper tank remained full.
The investigation found that the pilot inadvertently activated the water loading system after the initial landing. The operator suggested that the unintended activation may have occurred while the pilot was applying force to the control column to navigate the aircraft across the lake during the floating phase. The presence of the extended scoops and the weight of the full water tank significantly increased drag and altered the aircraft's performance characteristics during the takeoff roll.
Findings
- The primary cause of the accident was the attempted takeoff in an incorrect configuration, with the water scooping mechanism extended.
- The extended scoops and the weight of the full hopper tank created excessive drag, preventing the aircraft from reaching necessary takeoff speeds.
- The sudden decision to abort the takeoff, combined with the aircraft's weight and drag, induced a rapid nose-down pitch.
- The impact with the water surface was the direct cause of the structural damage to the propeller, engine mount, and ventral fin.
Safety action
Following the incident, the operator conducted a safety briefing for all personnel to emphasize the necessity of discharging all water during any period of difficulty managing the aircraft, whether in flight, on water, or on the ground. Additionally, a refresher training session was organized to reinforce emergency procedures and the importance of strict adherence to checklist protocols.