What happened
On May 6, 2019, an AS 350 B2 helicopter, registration PT-YTJ, departed from Novo Aripuanã Aerodrome (SWNA) in Amazonas, Brazil. The flight was intended to transport the pilot and three passengers to an inn located on the Acari River. During the en-route phase, the aircraft disappeared. Following a search operation, the wreckage was located on May 10, 2019, in a forested area near the Aripuanã River. The impact resulted in the destruction of the aircraft and four fatalities (the pilot and three passengers).
The investigation
CENIPA's investigation focused on the pilot's medical status and recent flight behavior. While the pilot held a valid medical certificate (CMA), the certificate contained a specific restriction: "solo flight prohibited." This was due to a medical condition involving mononeuropathy in the lower limbs following previous surgeries, which caused paresis (weakness) in the left foot.
Investigators also reviewed footage and witness reports indicating that the pilot had been performing unauthorized aerobatic maneuvers in the area prior to the accident. Furthermore, the investigation noted that the wreckage site had been disturbed by third parties before the official investigation team arrived, which complicated the analysis of the initial impact point. The engine was found to have been functioning normally at the time of the accident.
Findings
- Physical Limitations: The pilot's medical condition, specifically the weakness in the left foot, may have prevented the full use of flight controls, such as the pedals required for yaw control, potentially leading to a loss of control.
- Unsafe Maneuvers: The pilot performed unplanned and impulsive aerobatic maneuvers that likely exceeded the certified flight envelope of the AS 350 B2, potentially causing structural stress or loss of control.
- Organizational Failure: The operator hired the pilot as a freelancer despite the known "no solo flight" restriction in his medical certificate, revealing a failure in the company's recruitment and selection processes.
- Regulatory Gaps: There was a lack of effective mechanisms to monitor or enforce the restrictions placed on pilots with specific medical limitations, and the existing regulations were insufficient to prevent the pilot from operating in a manner inconsistent with his medical status.