What happened
On December 5, 2011, an Embraer EMB 810C, registration PT-EEK, was operating a passenger flight from Tabatinga (SBTT) to Rio Branco (SBRB). During the flight, the crew was notified by Rio Branco Approach that weather conditions at the destination had degraded significantly, transitioning from visual to instrument procedures with visibility dropping to 600 meters and a ceiling of only 500 feet, accompanied by wind gusts up to 30 knots.
The crew evaluated their primary and secondary alternates. The first alternate, Novo Campo (SWNK), was deemed unusable due to adverse weather. The second alternate, Fazenda Água Limpa (SDNQ), also presented unfavorable conditions. With approximately 30 minutes of fuel autonomy remaining, the pilot decided to execute a precautionary landing on the BR 317 highway, near kilometer 02, approximately 30km from Rio Branco. The landing was completed successfully without damage to the aircraft, and all four occupants remained uninjured.
The investigation
The investigation by CENIPA examined the flight communications and the crew's decision-making process. Investigators found that the aircraft's radios were experiencing significant transmission and reception difficulties, which hindered communication with Air Traffic Control (ATC).
Records showed that the pilot descended from FL050 to FL040 without authorization and failed to notify ATC of the intended precautionary landing or the low fuel state. Furthermore, the crew did not utilize the transponder emergency codes (7600 or 7700) or broadcast on the international emergency frequency (121.5 MHz) prior to the landing. The investigation also noted that while the crew had sufficient fuel to meet legal minimums, the lack of effective communication and the rapid degradation of weather at all available airfields created a critical situation.
Findings
- Adverse meteorological conditions at the destination and both alternate aerodromes.
- Inadequate flight planning, as weather information was available that could have allowed for better preparation.
- Pilot judgment regarding altitude changes and the decision to land without notifying ATC.
- Communication difficulties caused by malfunctioning aircraft radio equipment.