What happened
On May 14, 2004, at approximately 22:35 UTC, an EMB-120 ER, registration PT-WRO, crashed into a tropical forest near Manaus, Amazonas. The aircraft was operating a scheduled passenger flight from Tefé to Manaus. During the approach, the aircraft was being vectored by Manaus Approach to facilitate the priority landing of another aircraft carrying a critically ill patient.
While the crew was following instructions to intercept the localizer and descend to 2,000 feet, the aircraft's descent profile became uncontrolled. The last communication from the crew was a readback of an instruction to maintain 2,000 feet, even though the aircraft was already at 1,300 feet at that moment. The aircraft struck the treetops at high speed, resulting in the total destruction of the airframe and 33 fatalities (30 passengers and 3 crew).
The investigation
CENIPA investigators examined the wreckage, flight data, and cockpit voice recordings. While the engines and propellers were found to be operating normally at the time of impact, the investigation revealed significant technical and operational discrepancies. The Digital Flight Data Recorder (DFDR) was non-functional, and the Cockpit Voice Recorder (CVR) was difficult to analyze due to high background noise.
Investigators also reviewed maintenance logs, which showed a history of autopilot malfunctions, including pitch oscillations and failure to capture selected altitudes. Furthermore, the investigation looked into the air traffic controller's workload, as the controller was simultaneously managing the priority landing of the medical flight.