The radar screens of the new Air Traffic Management System (ATMS) of the Civil Aviation Department (CAD) today (December 12) were unable to display some of the flight information temporarily and the information eventually reappeared automatically. The situation resembled the occurrence on November 29. However, during the incident today, air traffic control officers (ATCOs) were able to obtain all of the flight information through Automatic Dependent Surveillance–Broadcast (ADS-B) technology, which was recently implemented, on another display screen next to the radar screen. Aviation safety was not affected by the incident.

     "The incident took place around noon today. The radar screens were unable to display some of the flight information such as flight callsigns and flight speed while positions and altitudes of the flight targets were still available on the radar screens. The flight information reappeared automatically after about 75 seconds. The situation differed from the occurrence on November 29 because, benefiting from the CAD’s expedited full implementation of ADS-B in the Hong Kong Flight Information Region (HKFIR), ATCOs have been able to get the information on flights inside the HKFIR through ADS-B since last Thursday (December 8). Therefore, ATCOs today could obtain the information temporarily missing from the radar screen by viewing another screen at the same working position through ADS-B. Nevertheless, for the sake of prudence, the ATCOs suspended the handling of departing flights for four minutes to safeguard aviation safety," a CAD spokesman said.

     Members of the senior management of Raytheon Company, the contractor for the new ATMS, are currently in Hong Kong to follow up on the occurrence on November 29. According to their investigation and analysis, the cause of the occurrence today was not new but similar to that of November 29. The root cause was that, when working staff carried out system maintenance in retrieving and archiving data, the process took priority, and the flight plan association process was expected to take place shortly afterwards, resulting in the momentary flight plan dis-association. The CAD tentatively believed that the incident was caused by working staff who failed to follow the recommended procedures promulgated by the department earlier, which was to avoid retrieving and archiving data from the Main System. This was not a new issue.

     "According to the investigation report regarding the incident on November 29 submitted by Raytheon to the CAD last week, staff should not retrieve data from the Main System to ensure the Main system operation is not impacted. With regard to the incident today, the department has reminded working staff again the relevant procedures so as to avoid recurrence," the spokesman said.

     There was no loss or corruption of flight plan data during the occurrence today. All other functions of the new ATMS were functioning normally. ATCOs can obtain all the flight information through the radar system and ADS-B simultaneously at all times. Hence, neither air traffic management, nor aviation safety were affected.  The Fallback system and the Ultimate Fallback System of the new ATMS were operating normally and available for selection at all times. Raytheon has already developed the software fix to optimise the system. The CAD will conduct the testing and adopt the software fix to avoid the recurrence of similar incidents after the peak traffic season during Christmas and Lunar New Year.

     The CAD issued two press releases regarding the incident on November 29 (see related links).

Ends/Monday, December 12, 2016
Issued at HKT 22:30

NNNN