The City of Derry Airport is being shut by the flight regulator until further notice because of safety concerns.
The regulator found fault with City of Derry Airport's safety provisions
The Civil Aviation Authority decided to provisionally suspend its licence following an inspection this week.
Problems found include lack of an effective bird control plan, unsuitable temporary repairs to the area where planes park and poor runway drainage.
The airport advised travellers to contact airlines about flight cancellations and diversions.
In a statement, the airport management said they were "100% committed to maintaining the highest safety standards".
"While this an exceptional step by the CAA, the airport is confident that a position can be reached to ensure it is operational as soon as possible.
"The public will be advised immediately of any update and it is understood airlines will provide further updates on Friday".
Package holiday resorts
The airport closes at midnight, and Ryanair have cancelled all Friday's flights to and from the airport.
The airline, which announced on Thursday a new route to Bristol would begin in November, said customers booked on cancelled flights would be fully refunded.
British Airways rescheduled their flights to operate through Belfast International Airport, more than 60 miles away.
The Dublin and Glasgow routes will be affected and passengers are advised to check-in as normal at City of Derry Airport for coach transfers to Belfast.
The Civil Aviation Authority said the suspension was provisional and the onus was on the airport to fix the situation.