The Flight Data Processors (FDPs) of the main system of the Civil Aviation Department (CAD)'s new Air Traffic Management System (ATMS) experienced a momentary hitch today (April 8). Once the Fallback System took up the role of Main System, the operation of the ATMS resumed normal. All flight targets were continuously displayed on the radar screens throughout the occurrence, and some media sources suggesting that a large number of flights went missing from the radar screens is factually not correct. Besides, Air Traffic Control Officers (ATCOs) were able to keep direct voice communications with the pilots at all times and obtain all of the flight information through Automatic Dependent Surveillance–Broadcast (ADS-B) technology to provide air traffic control (ATC) services. As a precaution, the ATCOs deferred giving clearance to departure flights for about 15 minutes. Arrivals and flights flying through the Hong Kong Flight Information Region were not affected. Aviation safety was not affected by the incident.

     "At 11.28am today, the ATMS issued an alert stating that the FDPs were not functioning properly. Most of the flights had their full information shown on radar screens, except for a few which could only show their position and altitude information. The technical staff working on site immediately followed up and carried out investigations. The ATCOs continued to provide services as usual once the technical staff switched the system to the Fallback System at 11.40am according to standard procedures. The operation of the initial Main System resumed normal after it was re-booted. It now serves as the Fallback System," a CAD spokesman said.

     "The new ATMS has multiple fallback systems to tackle different scenarios. The Fallback System is a separate but identical system to the Main System, which can immediately take up the role of Main System for continuing the operations of the system in the event of failure of the Main System. As a matter of fact, all flights were still continuously displayed on the radar screens throughout the occurrence. ATCOs were also able to obtain all of the flight information through ADS-B technology," he added.

     According to the initial investigation results of the contractor's representative, who has visited the ATC Centre this afternoon, it was believed that the occurrence was caused by accumulation of users' preferences settings exceeding the preset system limit. Hence, the FDPs could not function properly. All ATCOs were asked to stop renewing or inputting new users' preferences settings for the time being.

     The CAD attaches great importance to the occurrence and has tasked the contractor to submit a full report by next week and to provide a permanent solution as soon as possible to prevent recurrence. The CAD has also informed the ATMS Expert Panel members and will update them on the follow-up actions in due course.

Ends/Saturday, April 8, 2017
Issued at HKT 20:54

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