Airbus A320-232 N590JB incident near Sacramento, California

Probable cause

The first officer’s inadvertent activation of the parking brake in flight, which led to the airplane abruptly stopping and all four of its main landing gear tires deflating, and his use of a nonstandard procedure to cancel the airplane's monitoring alert system.

NTSB analysis

Upon touchdown and with the first officer as the pilot flying, the airplane rapidly decelerated. After touchdown, air traffic control tower personnel notified the flight crew that smoke and sparks were coming from the airplane's main landing gear. The captain took control of the airplane and maintained directional control as it abruptly came to stop about 2,000 feet from the touchdown point. Postaccident examination of the airplane revealed that all four main landing gear tires were deflated and showed evidence of being locked on touchdown and that the main wheel rims were ground down. According to recorded digital flight data, the parking brake engaged about 5,116 mean sea level and remained engaged throughout the remainder of the flight and landing roll. The data also indicated that the speed brake was activated about 4 seconds before the parking brake. The speed brake lever is on the left side of the center console near the parking brake switch, which is at the bottom center of the console. The first officer stated that he activated the speed brake. It is likely that the first officer inadvertently activated the parking brake at the same time.

The flight crew stated that they were unaware of any indications or warnings related to the parking brake system during flight. The airplane's Electronic Centralized Aircraft Monitoring (ECAM) system should alert the flight crew when the parking brake is engaged in flight. However, after the accident, the first officer stated that he selected and held down the ECAM emergency cancel pushbutton for several seconds and that this was his typical procedure to preempt the autopilot disconnect audio. This action also terminated, in part, most of the visual alert indications associated with the in-flight parking brake activation. (The alerts would appear in the cancelled caution field on the status page and could be recalled, if necessary.) The operator's procedures state to only use the ECAM emergency cancel pushbutton to suppress spurious master cautions. A review of the airplane's cockpit voice recorder transcript revealed no audible autopilot disconnect or parking brake activation warnings. Examination of the airplane's parking brake and ECAM revealed no mechanical malfunctions or failures that would have precluded normal operation. If the first officer had not cancelled out most of the visual alert indications associated with the in-flight parking brake activation, it is likely that a visual warning would have alerted the flight crew to the in-flight parking brake activation.

Text from the NTSB. Open the NTSB docket for WPR10IA430 for the full record.