What happened
On October 10, 2009, at approximately 12:30 UTC, a Piper PA-36-300, registration PR-AGB, was performing agricultural spraying operations near Fazenda Castelhana in Romaria, Minas Gerais. The aircraft departed from a nearby landing strip to spray a target area at Fazenda Vereda.
After completing the first spray pass on a heading of 170 degrees, the pilot initiated a right-hand turn to prepare for a second pass. During this maneuver, the pilot noticed a loss of lift. In an attempt to manage the situation, the pilot immediately jettisoned the remaining chemical payload. However, the aircraft continued to lose airspeed, leading to the right wing striking the ground. The aircraft then slid 34 meters along the ground, rotating 270 degrees to the right before coming to a halt. The aircraft sustained substantial damage, but the pilot remained uninjured.
The investigation
The investigation by SERIPA III established that the aircraft was within its specified weight and balance limits, carrying 105 liters of aviation gasoline and 480 liters of agricultural product. The pilot was fully qualified with valid medical and technical certifications, though this was their first experience performing this specific type of flight operation.
Investigators analyzed the environmental conditions, noting a wind from 20 degrees at 12 knots. Because the flight path was on a 170-degree heading, the aircraft was subject to a tailwind component. It was determined that this wind component likely pushed the aircraft outside the intended turn radius. To compensate and realign with the flight path, the pilot likely increased the bank angle. This increased bank angle significantly raised the stall speed.
Findings
- The pilot's lack of experience with this specific type of flight operation.
- Improper use of flight controls during the maneuver.
- The use of a high bank angle to correct the flight path during a tailwind component, which increased the stall speed and led to an aerodynamic stall.