What happened
On May 19, 2022, an AT-502B aircraft, registration PS-CT/TN, was performing agricultural spraying operations over a cotton plantation at Fazenda Cambará I, in Correntina, Bahia. The aircraft was executing a local crop-dusting flight, following a routine pattern of spraying lanes in a northeast/southwest direction.
During the mission, the pilot attempted to transition to a new spraying lane by performing a left-side reversal turn, often referred to as a "balloon" maneuver. While the aircraft was on a descending trajectory to reposition for the next pass, it collided with low-voltage electric-power transmission lines at an altitude of approximately 10 meters. The impact caused minor damage to the aircraft's propeller assembly, left-hand engine exhaust, left-hand wing, left-hand aileron, and the spray system. Additionally, the collision damaged the low-voltage power cables. The pilot escaped the incident uninjured and successfully returned the aircraft to the runway.
The investigation
CENIPA's investigation focused on the operational circumstances and the pilot's decision-making during the maneuver. Investigators examined the aircraft's maintenance records, which were found to be up to date, and confirmed the aircraft was within its prescribed weight and balance limits. The pilot's qualifications, including a valid Commercial Pilot license and Agricultural Pilot rating, were verified as adequate for the mission.
The investigation analyzed the environmental conditions, noting that while the weather was suitable for flight, the timing of the operation placed the rising sun in a position that created significant glare. Investigators also looked into the pilot's familiarity with the terrain, noting that while the pilot was the operator's employee and knew the area well, the lack of updated obstacle maps and a formal reconnaissance of the specific area contributed to the risk.
Findings
- Inattention: The pilot's attention was focused on stabilizing the aircraft along the correct flight axis, which prevented the timely perception of the approaching power lines.
- Sun Glare: The position of the rising sun created a glare that temporarily blinded the pilot's vision, hindering the ability to identify the wires.
- Inadequate Flight Planning: The timing of the spraying operation was unfavorable, as the sun's luminosity and position relative to the flight path created a high-risk environment.
- Risk Assessment: The choice of the reversal turn location near the power lines indicated a failure to adequately assess the risks associated with the descent trajectory.
- Excessive Self-Confidence: The pilot's familiarity with the region may have led to an overreliance on memory rather than using updated maps to identify obstacles.
Safety action
The operator was instructed to implement proper signage for the electric-power lines crossing the property, in accordance with Brazilian national standards (NBR 7276). Furthermore, the pilot was advised to perform visual ground reconnaissance of all areas prior to spraying and to plan flights specifically to manage risks related to sunlight glare and obstacle identification.