What happened
On the evening of the accident, an aircraft departed from Marabá Airport at 17:25 local time. Due to an error in flight preparation and a misunderstanding of the computerized flight plan, the crew entered a heading of 027° instead of the intended 270°. The flight was initially cleared to climb to FL290, and the aircraft maintained its incorrect heading for approximately 40 minutes. Following a descent instruction to FL200 from Belém ACC, the crew struggled to locate navigational aids and lost all radio communication.
As the aircraft descended further to FL40, the course was adjusted to 090 degrees. The crew subsequently navigated by following a river on a heading of 165 degrees. During this period, visibility was severely compromised by haze and the setting sun, making navigation difficult. Despite attempts to establish radio contact on various frequencies, the crew could not reach air traffic control or locate necessary navigational aids. After eventually locating an NDB, both engines ceased operation because of fuel exhaustion. The pilot attempted an emergency landing, but the aircraft crashed into the jungle approximately 60 km from São José do Xingu. The impact resulted in 12 deaths and 42 injuries, and the aircraft was destroyed.
Findings
Investigations revealed that the primary cause of the navigational error was a flawed graphical representation in the flight plan computer, which displayed a four-digit magnetic bearing without a decimal separator; this caused '027.0' to be read as '0270'. Several human and operational factors contributed to the accident:
- The crew experienced misleading perceptions and reinforcement of the incorrect heading during cockpit coordination.
- A lack of attention prevented the crew from recognizing that they were off-course, evidenced by their failure to notice the loss of standard radio communications.
- Environmental conditions, specifically sunset and dry fog, hindered visual navigation.
- Operational failures included inadequate supervision of cockpit activities and poor flight planning techniques.
- The crew maintained a strong predisposition to reach their destination, which led them to continue searching for headings and river contours despite the mounting difficulties.