What happened
On November 14, 2010, an A188B performing agricultural spraying operations collided with low-voltage electrical transmission lines near Uruguaiana, Rio Grande do Sul. The aircraft, registered as PT-FFD, was executing its second spray run of the day using a standard "carousel" flight pattern.
During a pass with a heading of approximately 260 degrees, the aircraft's landing gear struck the power lines, which were positioned at an estimated height of 9 meters. The impact caused the wires to break and the aircraft to enter an uncontrolled descent, eventually striking the ground with the engine still at power. The pilot sustained minor injuries, but the aircraft suffered heavy damage.
The investigation
CENIPA investigators examined the flight conditions, the aircraft's mechanical state, and the pilot's operational procedures. The investigation confirmed that the pilot was fully qualified, with valid medical and technical certifications, and that the aircraft was within its weight and balance limits. Meteorological conditions were favorable for visual flight, with high visibility and no significant cloud cover.
Investigators found that while the pilot had worked in the same area approximately 15 days prior and was aware of the presence of power lines in the region, a thorough reconnaissance of the specific obstacles for that day's mission had not been performed. Although the pilot noted difficulty seeing the wires due to sun glare, the investigation concluded that the primary issue was the lack of a recent, detailed survey of the area's hazards.
Findings
- Inadequate flight planning: The pilot failed to perform a proper reconnaissance and marking of obstacles in the application area and its surroundings prior to the flight.
- Improper pilot judgment: The pilot did not adequately evaluate or maintain a safe flight altitude to clear all potential obstacles.
- The aircraft was operating within all legal and mechanical parameters at the time of the accident.