What happened
On November 5, 2008, an EMB-201A agricultural aircraft, registration PT-GVN, was performing crop spraying operations near Eldorado do Sul, Rio Grande do Sul. While completing the final application pass of the day, the pilot attempted a right-hand turn to cover a small remaining section of the field. During the recovery phase of this maneuver, the aircraft's landing gear struck a single stabilizer/lightning protection cable located at the top of the high-voltage transmission towers.
The impact with the cable caused the aircraft to pitch nose-down abruptly. Although the pilot attempted to pull back on the controls to level the wings, the momentum from the collision forced the aircraft into the ground approximately 165 meters from the power lines. The aircraft slid 35 meters along the ground, rotating 180 degrees before coming to a complete stop. The pilot sustained minor injuries, while the aircraft suffered severe damage to the landing gear, right wing, propeller, and forward fuselage.
The investigation
CENIPA's investigation focused on the flight path and the visibility of the obstacle. Investigators found that while the pilot was aware of the high-voltage lines crossing the field, the specific stabilizer cable was difficult to discern because it did not follow the curvature of the main transmission lines and sat higher on the towers. The investigation also noted that the power line towers were positioned on uneven terrain, with the tower on the right side of the aircraft being lower than the one on the left.
Furthermore, the investigation examined the operational environment, noting that the use of GPS for flight paths had eliminated the need for ground observers (signalmen) who previously helped guide pilots around obstacles. The investigation also looked into organizational pressures, noting that the pilot's performance was subject to client preference, which could influence operational decisions.
Findings
- Inadequate maneuvering judgment: The pilot failed to maintain sufficient altitude and distance to safely clear the obstacle during the recovery maneuver.
- Inadequate flight planning: The flight plan did not sufficiently account for the uneven terrain of the power line towers or the presence of the single, high-altitude stabilizer cable.
- Operational pressure: There was evidence of management deficiencies, as the company's supervision allowed for potential pressure from clients regarding the quality and completeness of the spraying service.
- Lack of ground observers: The absence of ground-based personnel to assist in obstacle identification increased the risk during low-level maneuvers.