The UK-based air traffic control company have said the current delays at UK airports are due to difficulties switching from night time to daytime operations, and engineers are currently working to rectify the problem.
A NATs statement read: "Due to a technical problem at Swanwick we are currently experiencing some difficulty switching from night time to daytime operation.
"This may result in some delays for which we apologise. Engineers are working to rectify the problem as soon as possible."
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