What happened
On December 1, 1994, an EMB-202 Ipanema, registration PT-UHT, was performing agricultural spraying operations over a rice plantation in the municipality of Dom Pedrito, Rio Grande do Sul. The pilot was executing spraying passes beneath high-voltage power lines that ran perpendicular to the flight path.
Upon exhausting the herbicide payload, the pilot attempted to return to the support base for refueling. To do so, the pilot initiated a left-hand climbing turn intended to fly over the power lines rather than under them. During this maneuver, the left wing of the aircraft struck the highest wires of the electrical network. The collision caused the pilot to lose control of the aircraft, which continued in an uncontrolled flight for approximately 400 meters before impacting the ground in a level-wing attitude. The impact triggered a post-crash fire that destroyed the aircraft. Although the pilot managed to egress the aircraft, they sustained severe burns over 75% of their body and subsequently passed away at a hospital.
The investigation
CENIPA's investigation focused on the operational procedures and the physical characteristics of the electrical infrastructure. The investigation confirmed that the EMB-202 was in airworthy condition, with all maintenance services up to date. The pilot was highly experienced, holding a valid Commercial Pilot License and Agricultural Pilot Technical Certificate, and had successfully performed similar missions in the same area previously.
Investigators examined the electrical network, which consisted of three main transmission wires approximately 2 inches in diameter, and two auxiliary earth wires (approximately 1/4 inch in diameter) positioned two meters above the main lines. The investigation established that while the pilot had been successfully flying under the wires during previous passes, the decision to change the flight profile for the return leg led to the collision with the less visible auxiliary wires.