What happened
On April 10, 2004, an EMB-201A, registration PT-UFJ, departed from the Areia Branca aerodrome in Mato Grosso, Brazil, to perform a simulated agricultural spraying maneuver. The pilot, an experienced agricultural aviator, performed a low-level pass over a soybean field located approximately 500 meters from the airfield. During the maneuver, the aircraft struck the ground.
Although the aircraft was certified for a single occupant, the pilot was transporting a passenger in the nacelle. To accommodate the passenger, who was standing behind the seat, the pilot had moved the pilot's seat to its lowest and most forward position. The aircraft sustained severe damage to the engine, propeller, and structure. The pilot sustained fatal injuries, while the passenger suffered serious injuries.
The investigation
CENIPA's investigation established that the pilot operated the aircraft without the owner's authorization. The investigation focused on the aircraft's configuration and stability during the final approach to the field. A ground simulation using an identical aircraft model revealed that the forward position of the seat significantly restricted the movement of the control column. Specifically, while the pilot could move the stick forward to pitch down, the physical obstruction prevented the necessary rearward movement to pitch up.
Furthermore, the investigation calculated that the aircraft's Center of Gravity (CG) was at approximately 34% of the Mean Aerodynamic Chord (MAC), which exceeded the aft limit of 27% MAC. This shift was caused by the combined weight of the pilot, the passenger, and the remaining fuel, despite the empty spray tank.
Findings
- Improper Center of Gravity: The CG was located at 34% MAC, exceeding the 27% limit, causing longitudinal instability.
- Control Limitations: The forward seat position prevented the pilot from effectively using the control column to pitch the aircraft up.
- Unauthorized Passenger: The aircraft was operated in violation of its single-occupant certification to carry a passenger standing in the nacelle.
- Pilot Decision Making: The pilot's actions were characterized by overconfidence and a disregard for established safety procedures and operational limits.
- Operational Culture: A local culture among agricultural pilots of carrying unauthorized passengers likely influenced the pilot's decision-making.