What happened
On March 22, 2006, at 16:35 local time, a Boeing 737-400, registration PR-BRC, was performing a scheduled flight from Rio de Janeiro (Galeão) to São Paulo (Congonhas). The aircraft was carrying 127 passengers and 6 crew members.
Upon approaching runway 35L at Congonhas, the aircraft encountered a wet surface. During the landing roll, the flight crew was unable to maintain braking effectiveness, causing the aircraft to deviate to the left. The aircraft overran the end of the runway, crossing the threshold of the opposite end and coming to a stop near an embankment adjacent to a taxiway. While there were no fatalities or injuries among the 133 occupants, the aircraft struck a runway lighting spot, causing damage to airport infrastructure. Due to the excursion, the crew initiated an emergency evacuation, which took approximately 5 minutes and 40 seconds, significantly exceeding the standard 90-second target.
The investigation
CENIPA's investigation focused on the runway conditions, aircraft mechanical status, and crew decision-making. Technical inspections of the tires performed by Goodyear confirmed that the aircraft had experienced hydroplaning. Inspements of the braking and wheel assemblies by Revisa Serviços Aeronáut and the aircraft's technical logs showed no mechanical defects in the braking system or tires.
Regarding the aircraft's configuration, investigators noted that the number 1 engine reverser was inoperative but locked in the forward position in accordance with the Minimum Equipment List (MEL).
Analysis of the runway surface at Congonhas revealed a critical issue with friction levels. Recent measurements indicated that several sections of runway 17R/35L had friction coefficients well below the required maintenance level of 0.50, with some points as low as 0.30. Previous safety reports from other airlines had also warned of extremely slippery conditions at the airport.
Findings
- Low runway friction and the presence of water led to hydroplaning, preventing the aircraft from stopping within the runway limits.
- The pilot failed to sufficiently anticipate the possibility of rain despite the weather forecast (TAF) indicating potential precipitation.
- The pilot's decision-making was compromised by a landing that involved a float on the runway, which reduced the available stopping distance.
- The operator lacked specific operational procedures for landing at Congonhas during wet conditions, particularly when facing known runway friction issues.
- The aircraft was operating with only one functional engine reverser.