What happened
On May 18, two Embraer aircraft, PT-GJZ and PT-GKL, were operating flights toward Imperatriz, Maranhão, when they collided in mid-air. The PT-GJZ had departed from São Luís, while the PT-GKL originated from Sena Madureira, Pará.
During the flight, the pilot of the PT-GKL reported being near the Araguaia River, maintaining an altitude of 2,000 feet. Shortly after, the pilot reported being near the Tocantins River and noted that the PT-GJZ was visible at approximately 1,500 feet. At that moment, the PT-GJZ entered a cloud layer and performed a right turn, ascending to 2,500 feet. During this maneuver, the PT-GKL struck the PT-GJZ.
The impact caused the PT-GJZ to crash, resulting in a post-impact fire. All occupants of the PT-GJZ were killed. The PT-GKL managed to perform an emergency landing in the Tocantins River, and while there were several injuries among the occupants, only one fatality occurred on that aircraft.
The investigation
CENIPA's investigation focused on the meteorological and operational conditions at the time of the accident. Investigators established that the weather at the Imperatriz aerodrome was below Visual Flight Rules (VFR) minimums, with cloud ceilings as low as 300 feet.
Technical analysis revealed that the aircraft were flying in multiple cloud layers, which prevented the pilots from maintaining the required horizontal and vertical separation from clouds. Furthermore, the investigation examined the functionality of the local radio station and the effectiveness of the onboard communication equipment. The investigation also noted that the firefighting response was significantly delayed because the local fire brigade could not reach the crash site due to difficult terrain, leaving the wreckage burning for over 24 hours.
Findings
- Meteorological conditions: The weather was below VFR minimums, making visual flight unsafe.
- Lack of coordination: The pilots were unable to maintain visual separation due to the cloud layers.
- Communication limitations: The radio station in Imperatriz operated with limited hours, which caused coordination conflicts, as some aircraft used frequencies (131.1 and 126.7) that were not monitored during certain periods.
- Equipment limitations: The onboard VHF radio in the PT-GKL had a limited range, providing only about two minutes of useful warning before the collision.
- Operational deficiency: There was a lack of individual flight monitoring for aircraft operating in the Amazon region, where terrain makes it difficult to locate single-engine aircraft.