Aviation Accident Summaries

Aviation Accident Summary WPR10IA430

Sacramento, CA, USA

Aircraft #1

N590JB

AIRBUS A320-232

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.

Factual Information

On August 26, 2010, about 1251 Pacific daylight time, an Airbus 320-232, N590JB, experienced an abnormal landing at the Sacramento International Airport (SMF), Sacramento, California. During touchdown and landing rollout on runway 16R, the airplane rapidly decelerated; the main landing gear tires blew out, and a minor tire-related fire erupted. All of the airplane's occupants, emergency evacuated by use of the cabin door slides. The airplane sustained minor damage. The two airline transport pilots, three flight attendants and 79 passengers were not injured. Seven passengers received minor injuries during the evacuation process. The airplane was registered to and operated by JetBlue Airways as flight number 262, under the provisions of Title 14 Code of Federal Regulations Part 121. Visual meteorological conditions prevailed and an instrument flight rules flight plan was filed. The scheduled domestic passenger flight originated about 1141 from the Long Beach Airport, Long Beach, California.According to the flight crew, the flight and approach to runway 16R were normal. The first officer was the pilot flying. Upon touchdown, the airplane began a rapid deceleration, and the first officer remarked to the captain that it felt like a main landing gear tire blew out. About this time, air traffic control tower personnel reported observing sparks and smoke in the area of the main landing gear. The captain took control of the airplane and maintained directional control as the airplane came to a stop about 2,000 feet from its touchdown point. The captain directed the first officer to initiate the Quick Reference Checklist (QRC) for ground evacuation, up to the evacuation decision point. At that time, air traffic control tower personnel confirmed smoke and fire were still visible around the main landing gear. Based on this information the captain elected to evacuate the airplane. Crash fire rescue personnel and equipment responded to the airplane, which was stopped on the runway. According to the flight crew and flight attendants, a swift and orderly evacuation was performed via emergency evacuation slides at both the forward main cabin doors and the rear left door. The rear right door was not used since a flight attendant observed smoke in the vicinity. The airplane was subsequently examined by the operator and Federal Aviation Administration (FAA) personnel. Airplane damage was limited to four deflated main landing gear tires and the wheel rims were ground down. The main landing gear tires showed evidence of being locked on touchdown. Ground damage was limited to minor grazing of the runway's surface. The airplane's Digital Flight Data Recorder (DFDR) and Cockpit Voice Recorder (CVR) were removed for analysis. The DFDR was examined by the operator and the National Transportation Safety Board (NTSB). According to the airplane's recorded flight data, the parking brake had become engaged in flight during the landing approach at approximately 5,116 feet mean sea level, and remained engaged throughout the remainder of the flight and landing roll. The parking brake activation occurred about the same time the autopilot was disconnected. The downloaded data indicated that the airplane was being configured with speed brakes about 4 seconds prior to the parking brake activation. The first officer stated that he activated the speed brakes. The airplane controls for the speed brake and parking brake are located in the center console in the near vicinity of each other. The speed brake lever is on the left side of the console and is activated by pulling the lever. The parking brake switch is on the bottom center of the console and is activated by pulling and rotating the switch. The CVR was examined by the NTSB Vehicle Recorder Division. The airplane's CVR revealed no sounds of the associated warning audio for the parking brake activation or autopilot disconnect. The CVR did reveal sounds captured around the time of the parking activation, however, the source of the sounds proved to be inconclusive. Non-essential communication existed during the sterile cockpit portion of the descent and approach. During interviews with the flight crew, neither pilot recalled any abnormal indications or cockpit warnings associated with the parking brake system prior to landing. The Electronic Centralized Aircraft Monitoring (ECAM) system is designed to monitor and advise the flight crew of the airplane's status. According to the manufacturer, if the parking brake is engaged in flight, the ECAM illuminates the master caution light, a single chime audio associated with the master caution light is given after a 3 second delay, and a parking brake on advisory message is presented. At 800 feet above ground level (agl), the alerts associated with the parking brake selected on in flight, are reactivated by the ECAM, in the event the alert or master caution was cleared by the flight crew. The applicable hydraulic system also provides an indication that the parking brake was activated in flight by the braking pressure indicators becoming operational. However, normal checklists do not require an in flight check of the brake pressure indicators. The operator performed an examination and functional test of the airplane's parking brake system and central warning systems in accordance with the manufacturer's maintenance manual, with no abnormalities noted. The parking brake control switch was also functionally checked by the operator with no abnormalities noted. A vendor conducted an examination and breakdown of the parking brake control valve and control switch with no abnormalities noted. On a follow up interview, the first officer described his personal technique where he would preempt the autopilot disconnect audio by selecting the ECAM emergency cancel pushbutton prior to disconnecting the autopilot and would hold it for several seconds afterwards. The autopilot disconnect warning audio (cavalry charge) is temporary and last a maximum of 1.5 seconds, if the autopilot is disengaged using standard procedures. Selection of the ECAM emergency cancel pushbutton would terminate the autopilot disconnect audio and any other present caution (master caution lights, ECAM alert message) for the rest of the flight. The alert would appear in the cancelled caution field on the status page and could be recalled if necessary. The operator's procedure has a note to use the ECAM emergency cancel pushbutton only for spurious master cautions. According to the manufacturer, if the ECAM emergency cancel pushbutton is selected prior to the parking brake on alert being displayed; the master caution light and single chime associated with the parking brake on alert would be inhibited. In addition, at 800 feet agl, the "parking brake on" alert message and master caution would not be reactivated. The ECAM emergency cancel pushbutton is not a parameter recorded by the DFDR.

Probable Cause and Findings

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.

 

Source: NTSB Aviation Accident Database

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