Irish investigators are probing a technical problem which affected airspace management in the Shannon air traffic control system, forcing restrictions on traffic flow.
Shannon not only handles Cork traffic but it serves as an interface to the crucial North Atlantic routes.
NOTAMs issued for the Shannon flight information region late on 2 October stated that controller-pilot datalink communications were out of service for upper airspace, as well as the oceanic transition areas.
The Irish Aviation Authority says its Dublin air traffic control system – independent of Shannon’s – was unaffected by the problem, and Dublin services continued to operate normally.
It states that it implemented contingency measures, including restricting traffic flow, while it investigated the issue and switched its operation to back-up systems. The probe into the disruption is continuing.