What happened
On the night of the accident, the crew of Flight 527 departed from runway 27 at 21:27. Following takeoff, ground control provided a No.16 departure clearance, directing the Lufthansa aircraft to perform a right turn toward the Caxias VOR while climbing to an altitude of 2000 feet. During the initial climb, air traffic controllers requested that the flight increase its airspeed. As a result, the speed rose to 304 knots, which surpassed the 250-knot limit established for the terminal control area below 10000 feet.
As the aircraft moved toward mountainous terrain, the departure controller was preoccupied with managing heavy traffic in a different sector of the radar scope. While the assistant controller failed to monitor the flight's progress, the aircraft continued on its path. Upon realizing the aircraft's position, the controller issued new instructions for a right turn to heading 140 and requested an increased rate of climb. Shortly after these commands, the Ground Proximity Warning System (GPWS) alerted the cockpit crew. The Lufthansa Airbus A320 (implied by flight number/context, though source only specifies aircraft type via context of LH527) struck trees on a mountain slope in a nose-up and left-wing-down orientation. The impact caused the aircraft to break up as it traveled 800 meters along the terrain, resulting in all occupants being lost.
Findings
Investigations determined that a significant breakdown in teamwork occurred among the personnel at Rio approach control. The departure controller provided incomplete instructions, which led the flight to follow a heading and altitude profile that resulted in the collision. Furthermore, the assistant controller, coordinator, and supervisor on duty failed to provide necessary support to the departure controller. A contributing factor was the crew's decision to follow these incomplete instructions without seeking clarification or an alternate procedure, leading to a period of 1 minute and 41 seconds where the aircraft flew under potentially dangerous conditions without proper bilateral communication.