What happened
On January 12, 2019, an EMB-202 agricultural aircraft, registration PT-UOL, was performing pesticide application maneuvers near Rio Verde de Mato Grosso, Brazil. The aircraft had departed from a nearby landing strip to conduct its second application flight of the day. The mission required navigating a narrow and rugged terrain, necessitating tight turns between application passes.
During a left-hand turn following a right-hand reversal, the aircraft entered a stall. The pilot reported that the stall warning alarm activated while the aircraft was at a 45-degree bank angle. In an attempt to maintain altitude and align with the wind, the pilot increased the bank angle, which inadvertently increased the load factor and further degraded performance. As the aircraft lost altitude, the pilot applied maximum power and extended the flaps to 30 degrees, but the maneuver failed to prevent the aircraft from striking a tree. The aircraft slid approximately 40 meters before coming to a stop. The pilot was uninjured, but the aircraft sustained substantial damage.
The investigation
CENIPA investigators confirmed that the pilot was fully qualified with valid medical and flight certifications. The aircraft was also in an airworthy condition, with all maintenance logs up to date and the aircraft operating within weight and balance limits. Meteorological conditions were favorable for flight.
The investigation focused on the pilot's response to the stall warning. Investigators noted that the pilot's actions—specifically increasing the bank angle during a stall—contradicted standard recovery techniques, which dictate reducing the bank angle and lowering the nose to decrease the load factor. The investigation also explored the possibility of negative transfer of learning, as the pilot had significant experience in much higher-performance aircraft, such as the Air Tractor AT-402 and AT-502, which may have led to an overestimation of the EMB-202's performance capabilities.