Edinburgh Airport has suspended all incoming and outgoing flights after an air traffic control outage brought the international hub to a standstill.
The IT issue is understood to have happened at about 08:30.
Some passengers have reported being stuck in planes on the runway.
Officials said they were working on the issue and that passengers should contact their airlines for updates on the situation.
An Edinburgh Airport spokesman said it was a “fluid situation” but that at the moment, he anticipated it affecting 27 departures and 11 arrivals.
“Due to an IT issue with our air traffic control provider, no flights are currently operating from Edinburgh Airport,” he said.
“Teams are working on the issue and will resolve as soon as possible.
“Passengers should contact their airline for the latest information on their flight.”