What happened
On August 28, 2002, an AT-402A operated by Rondon Aviação Agrícola departed from Guarantã do Norte, Mato Grosso, for a local flight. The pilot intended to conduct a visual reconnaissance of an area for upcoming agricultural spraying operations. During the flight, visibility was significantly reduced due to heavy smoke from regional agricultural burning, with horizontal visibility estimated at approximately 1,500 meters.
Seeking a place to land due to the deteriorating conditions, the pilot identified an uncertified dirt strip at Fazenda Graúna. Witnesses reported that the pilot, celebrating his birthday, performed a low-altitude pass over the strip and attempted a vertical maneuver. During this attempt, the aircraft entered a "snap stall" at the top of the maneuver. The pilot was unable to recover, causing the aircraft to strike the ground 350 meters from the side of the runway. The impact destroyed the aircraft, and a subsequent fire consumed the wreckage. The pilot escaped the wreckage uninjured.
The investigation
CENIPA investigators examined the wreckage and analyzed the flight sequence. While the pilot claimed he pulled up sharply to avoid an unlit low-voltage power line near the runway, investigators found that the aircraft's flaps were in the retracted position, suggesting the aircraft was not configured for a standard landing. Furthermore, the distribution of the debris indicated the aircraft maintained significant horizontal velocity at impact, which contradicted the theory of a stall occurring immediately after passing the power lines.
Evidence from witnesses and the flight profile suggested the pilot was performing unauthorized acrobatic maneuvers for which he was not trained or certified. The investigation also noted that the aircraft was not certified for aerobatic flight and that the pilot lacked sufficient experience in this specific airframe to manage such extreme attitudes.
Findings
- Improper Maneuvering: The pilot attempted unauthorized vertical maneuvers and low-altitude passes that exceeded the aircraft's operational limitations.
- Inadequate Planning and Judgment: The pilot decided to fly in adverse meteorological conditions and performed maneuvers without adequate preparation or consideration of the risks.
- Lack of Experience: The pilot lacked sufficient flight hours in the AT-402A to maintain control during high-stress, adverse flight attitudes.
- Operational Indiscipline: The flight violated established air traffic rules (IMA 100-12) regarding VFR minimums and exceeded the structural and certification limits of the aircraft.
- Inadequate Supervision: The operator lacked sufficient oversight to prevent pilots from making autonomous, high-risk operational decisions.