What happened
A flight departing from Rio de Janeiro-Galeão Airport was conducting a nighttime approach toward Fortaleza-Pinto Martins Airport in Ceará. During the descent, air traffic control provided instructions for the aircraft to descend to an altitude of 5,000 feet. While navigating toward the illuminated city, the captain lowered the aircraft below the authorized 5,000-foot limit.
As the flight progressed, the cockpit's altitude alert systems triggered two separate warnings regarding the low altitude. Additionally, the co-pilot alerted the captain to the presence of mountains directly in the flight path. Despite these multiple alerts, the descent continued until the aircraft type struck a forested peak within the Aratanha Mountain Range, situated approximately 26 km southwest of the destination airport. The impact caused the aircraft to break apart, resulting in 137 fatalities.
Findings
The investigation determined that the primary factor in the accident was that the captain ignored both the GPWS warnings and verbal alerts from the co-pilot while continuing a descent below the altitude assigned by air traffic control.