What happened
On May 17, 2016, a Piper PA 25-235, registration PR-TAC, was performing a pesticide application flight over a plantation at the Cachoeirinha Xingu Farm in Unaí, Minas Gerais. The aircraft took off from a nearby agricultural landing area to begin a spraying pass. During the execution of a reversal turn—a maneuver used to reposition the aircraft for the next pass—the pilot lost control of the aircraft, which subsequently collided with the ground. The impact resulted in fatal injuries to the pilot and substantial damage to the aircraft.
The investigation
CENIPA investigators examined the wreckage and the aircraft's maintenance history, finding that the engine and propeller were operating normally at the moment of impact. The aircraft's airworthiness certificate was valid, and all weight and balance parameters were within manufacturer limits. The investigation also reviewed the pilot's experience and the operational environment. While the pilot was qualified and held valid ratings, he was in his first season of agricultural flight operations.
Evidence from the site and witness accounts from an agricultural technician suggested that the pilot had been increasingly adopting a "bolder" flying style as the season progressed, specifically by shortening the turn radius and increasing the bank angle during reversal turns. Furthermore, the investigation noted that the pilot himself was responsible for programming the flight pattern into the aircraft's GPS, a task that could potentially lead to more aggressive maneuvering parameters.
Findings
- Loss of control in flight caused by the pilot failing to effectively manage flight controls during a low-altitude reversal turn.
- Extrapolation of flight envelope limits, specifically regarding load factor and airspeed, which led to a loss of lift (stall).
- Insufficient pilot experience in the specific aircraft type and the complexities of agricultural flight operations.
- Decreased situational awareness and judgment, potentially driven by increased self-confidence and a lack of risk perception as the season progressed.
- Inadequate risk management regarding the planning of flight patterns, as the pilot was responsible for defining the sequence of the plantation strips.