An investigation is underway after a problem with the Shannon Air Traffic Control radar system closed large parts of Irish airspace last night.
Flights in and out of Cork and Shannon Airport were suspended for a time – with no planes allowed to enter the impacted airspace.
Dublin and Belfast Airports were unaffected.
In a statement, the Irish Aviation Authority said an investigation into the radar issue is now underway.
Tech expert Jess Kelly said flights over Ireland could not be tracked.
“It was predominantly flights from cork and Shannon Airport affected,” she said.
“However, the whole of Irish airspace was impacted because we couldn’t track the flights were overhead.
“If you were on FlightRadar24 last night you will have seen pictures of Ireland where the majority of the country was clear in terms of our airspace aside from pockets of Dublin and moving towards the UK.”
— Jess Kelly ðŸ‘©ðŸ»ðŸ’» (@jesskellynt) October 2, 2018
Restrictions were lifted after a back-up system was deployed to allow planes take off and land – with Cork and Shannon airports back operating a short time later.
The IAA said flight schedules are currently returning to normal.
However, passengers due to fly out this morning are being urged to check with their airline as some delays are expected.