A software upgrade at the new air traffic control centre at Swanwick resulted in a number of delayed flights last week.
The new centre, which went live in January this year five years late and £180m over budget, closed down its main operations room for an upgrade last Wednesday night (20 March). Operations continued from its second control room.
According to a report in The Guardian flights were approaching the runway prior to takeoff when the shutdown was announced.
But a National Air Traffic Services spokesman told vnunet.com that the upgrade was planned and completed ahead of schedule.
"It was not a particularly big upgrade. Air traffic control systems are upgraded all the time. If you change something to do with the airspace you have to tell the computer," he said.
The upgrade shut the main control room from 10.15pm on Wednesday to 1.45am on Thursday, taking an hour and a quarter less than expected.
Upgrades take place about once a month, and flight restrictions are put in for safety reasons, explained the spokesman.
"The flight restrictions did mean some flights were delayed. At that time of night there aren't many flights which is why we do it," he said.
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