After air traffic controllers experienced radar system difficulties for the second time in a month, the controllers deemed the system "too malfunction-prone to operate safely," and closed the airspace for a short time Wednesday, according to published reports.
A spokeswoman for the Irish Aviation Authority, which operates the airport, said there was a "loss of functionality" for about 10 minutes Wednesday morning and further problems in the afternoon.
More than 200 flights were cancelled, delayed or diverted to other airports Wednesday after the airport was closed to inbound traffic for about two hours in the afternoon, followed by limited departures the rest of the day. The airport was functioning at about 50% and the IAA intended to bring the capacity to 80% Thursday night. Delays and cancellations were expected to last throughout the day and into Friday.
A notice on the airport's website said "an incremental approach towards operating the radar system at full capacity" would be taken over the course of the next 48 hours.
"As a result airlines may continue to experience delays departing and arriving into Dublin Airport during this time," the notice continued.
Carriers serving Ireland's largest airport include Ryanair and Aer Lingus, both based at Dublin. On Wednesday, Ryanair had cancelled about 75 flights and Aer Lingus about 23 flights. The carriers were both operating a full schedule on Thursday, but noted delays of about 45 minutes on inbound flights.
The radar malfunction was identified as a failure to display the call signs that identify incoming aircraft and the system's supplier, Thales ATM, is working to fix the problem.