What happened
On September 23, 2009, an EMB-202 aircraft, registration PT-UKS, was performing an agricultural spraying training flight over the Fazenda Nova Santa Cruz in Ponta Grossa, Brazil. The aircraft, operated by Pelicano Aviação Agrícola Ltda., was heavily loaded with full fuel tanks, 300 liters of water in the hopper, and spraying equipment installed, placing it near its maximum operational weight.
During the mission, the pilot performed several passes over the field. After the fourth pass, the pilot deactivated the Differential Global Positioning System (DGPS) and began executing more aggressive repositioning turns, increasing the bank angle and back pressure to better "feel" the aircraft's behavior. During one of these turns, the pilot reported feeling a vibration, known as a buffet, followed by a loss of control that resulted in the aircraft striking the ground. The impact, which first involved the left wing, caused severe injuries to the pilot and extensive damage to the aircraft's structure, engine, and propeller.
The investigation
CENIPA's investigation focused on the pilot's maneuvers and the aircraft's aerodynamic state during the turn. Investigators found that the pilot, while qualified, had very limited experience in this specific aircraft type, with only approximately 20 hours of flight time in the EMB-202.
The investigation established that the aircraft was operating near its maximum weight limit, which significantly reduces the margin for error during low-altitude maneuvers. The analysis of the flight sequence revealed that the pilot's decision to increase the bank angle and pull-back pressure while the aircraft was in a pre-stall state led to the aerodynamic stall. Furthermore, investigators noted administrative irregularities, as flight training records from the pilot's recent agricultural course were not properly maintained, making it impossible to verify the full extent of his training progress in specific maneuvers like reversal turns.
Findings
- Loss of control due to an aerodynamic stall caused by excessive bank angle and increased angle of attack during a low-altitude turn.
- The pilot failed to recognize the aerodynamic buffet as a critical warning to reduce the angle of attack.
- The pilot's decision to execute more aggressive maneuvers while the aircraft was near its maximum weight limit.
- Limited flight experience in the EMB-202 aircraft type.
- Inadequate maintenance of flight training records, preventing a full assessment of the pilot's proficiency in specialized maneuvers.