The problem has been traced to a faulty network card that caused the system, built by Thales, to overload.
“Thales ATM confirmed the root cause of the hardware system malfunction as an intermittent malfunctioning network card which consequently overcame the built-in system redundancy,” said the Irish Aviation Authority in a statement.
“Thales ATM also confirmed that the cause of the malfunction was the same for previous malfunctions which had occurred since 2 June, 2008. Thales ATM stated that in ten similar Air Traffic Control Centres worldwide with over 500,000 flight hours (50 years), this is the first time an incident of this type has been reported.”
The radar system had been suffering problems for some time and the airport was allowing fewer planes to take off and land because of fears about the radar system.
By on Wednesday at around 2pm ATC lost all height and location information on flights and ordered aircraft into a holding pattern before dispersing them to other landing spots.
Dublin is Ireland’s busiest airport and the shut down caused serious disruption to passengers, and particularly to Aer Lingus and Ryanair who based many of their services there.