Incident Overview
An airline transport pilot, holding 4,274 hours of flight experience, lost control of the airplane while landing on a runway measuring 7,752 feet in length and 150 feet in width. The prevailing crosswind caused the aircraft to drift off the right side of runway 31R.
Flight Data Recorder Analysis
Analysis of the flight data recorder (FDR) and cockpit voice recorder (CVR) provided detailed insights into the landing sequence. For the first ten seconds after touchdown, the number 3 brake received more brake pressure than the number 1 brake. Additionally, during the four seconds that thrust reversers were utilized, the number 2 engine achieved a higher N1 (fan speed) than the number 1 engine.
Wind Conditions
Just prior to touching down, the air traffic control tower reported winds from 250 degrees at 27 knots, with gusts reaching 38 knots. The operator used tabular data to determine the crosswind component, rather than utilizing a graph. When the graph was consulted, the crosswind component was calculated to be approximately 33 knots.
Aircraft Performance Limitations
According to the Airplane Flight Manual, the maximum demonstrated crosswind for this airplane is 30 knots. The actual crosswind component, as determined by the graph, exceeded this limit.
Conclusion
The factors identified during the investigation include the asymmetric application of brakes and thrust reversers, as well as the crosswind component exceeding the aircraft's demonstrated capability.