What happened
On December 4, 1994, an EMB-201A aircraft, registration PT-UEY, was performing aerial pesticide application over a sugarcane plantation at Fazenda Guatapará, São Paulo. The operation involved multiple aircraft flying in sequence, with each pilot beginning their spray run where the preceding aircraft had finished.
During the mission, the pilot attempted to maneuver the aircraft to clear a high-voltage power line. As the aircraft began its recovery maneuver, the tie-down ring located on the underside of the left wing struck a guy wire supporting a transmission tower. This impact, combined with the low airspeed resulting from the steep angle of climb, led to a loss of lift and a characteristic stall spin. The aircraft subsequently lost control and impacted the ground at a 4/5 pitch angle.
The investigation
CENIPA's investigation focused on the operational procedures and the pilot's maneuver execution. The investigation established that the aircraft's mechanical systems were functioning normally and that the pilot held valid commercial, agricultural, and IFR licenses.
Investigators examined the flight path, noting that the spraying runs were planned perpendicular to the power lines, which necessitated aggressive maneuvers to clear the obstacles at the end of each pass. The investigation also reviewed the pilot's experience, noting that while the pilot had 2,400 total flight hours, they had only 70 hours of experience in agricultural aviation and were performing their first actual spraying season.
Findings
- Deficient Planning: The flight path was perpendicular to the high-voltage lines, forcing pilots to execute difficult maneuvers. Additionally, the sequential nature of the operation caused pilots to focus on the aircraft ahead, reducing situational awareness regarding obstacles.
- Deficient Judgment: The pilot failed to correctly identify the appropriate moment to initiate the recovery maneuver to clear the power line.
- Lack of Experience: The pilot had limited experience in agricultural flight operations, with only 70 total hours in this specific type of mission.
- Operational Complexity: The simultaneous use of multiple aircraft in the same area increased the complexity of the mission and the demand for pilot attention.