Hong Kong’s aviation authority on Monday defended its new air traffic control system, insisting that its failures last Thursday had limited impact, even as it emerged that the department had to activate the system’s “ultimate” backup function. Kevin Choi, deputy director general of civil aviation, admitted that the new Auto Trac III system ran into trouble last week during a test run, after air traffic controllers input data about the biennial Airshow China expo in Zhuhai, Guangdong, which starts on Tuesday. Choi said that after staff entered the data, the system started to run very slowly. The department quickly switched back to the old system to direct traffic, he said. What are the problems affecting Hong Kong’s new air traffic control system? Choi insisted that only three controllers out of more than 50 working at the time were affected, dismissing reports that the HK$1.5 billion upgrade suffered from a “meltdown”. “Only three duties were affected and the three did not have to communicate with the flights,” Choi said on an RTHK programme on Monday. “The impacts were small.” Choi said that after controllers switched back to the old system to direct traffic, other members of staff entered the air show data into the new system again to check if it would malfunction again. This was done as a test run, so actual air traffic was being managed using the old system. The new system and its backup both got into trouble again during the tests. The controllers had to activate the new system’s “ultimate” backup system during that test run. Delays to new air traffic control system could lead to more cancelled flights The Civil Aviation Department’s (CAD) new system was originally scheduled to start working sometime from the end of October to the beginning of November. Choi said overseas experts were looking into whether the system was ready. Civic Party legislator Jeremy Tam Man-ho, who was himself a commercial pilot, was inside the air traffic control centre when the new system started to run into trouble. He was visiting alongside CAD staff to examine how the system was functioning. “I was there. The system had not collapsed at the time but I started to hear the warnings. I knew that 15 minutes after I left, the system collapsed,” Tam said on the same RTHK programme. Tam said the “ultimate” backup system was like Windows “safe mode”, referring to the computer system. “Under the safe mode, you could only do simple [air traffic control] tasks,” he said. He said air traffic controllers struggled to use the “ultimate” backup system for lack of training.