What happened
On October 3, 1996, at approximately 06:00, an agricultural HU-30 269.B helicopter, registration PT-HHA, operated by Aero Agrícola Recreio, was performing a visual reconnaissance flight over a target area for chemical spraying. The aircraft had taken off from the Usina União e Indústria airstrip, landed briefly at a designated base for approximately five minutes with the engine running, and then departed again to survey a 1,000-meter circuit.
While flying at a low altitude between two terrain elevations, the aircraft struck low-voltage power lines. The impact caused the helicopter to lose altitude and crash into the ground approximately 80 meters ahead of the wire strike. Following the impact, the aircraft caught fire due to fuel leaking from the tanks onto hot engine components. The pilot sustained fatal injuries and died at the scene.
The investigation
CENIPA investigators examined the circumstances of the flight, the aircraft's maintenance status, and the environmental conditions. The investigation confirmed that the pilot was fully qualified, with a valid commercial helicopter license and medical certificate. Meteorological conditions were favorable for visual flight, with good visibility and light winds.
Regarding the aircraft, investigators noted that PT-HHA was operating with an expired airworthiness certificate. However, the investigation found no evidence of mechanical failure; witnesses reported the engine sounded normal until the collision, and the power plant's performance appeared unaffected. The investigation also noted that the low-voltage wires were not marked with any visual aids, making them difficult to detect.
Findings
- Deficient planning: The pilot failed to plan the reconnaissance flight with an adequate safety altitude, flying too low to identify obstacles.
- Deficient judgment: The pilot's decision to fly at a low altitude during the initial survey prevented the identification of utility poles and wires.
- Deficient infrastructure: The low-voltage power lines lacked proper marking or visibility aids, which significantly hindered detection during agricultural operations.
- Operational risk management: There was a lack of adequate risk management regarding the identification of hazards within the spraying area.