The passport control system failure led to long queues at the three airports, with the outage beginning about 7.30am and the system coming back online by about 10.30am.
Airlines are experiencing check-in delays due to a system issue. Check with your airline for latest information. Thanks for your patience.— Sydney Airport ✈️ (@SydneyAirport) 21 May 2017
Melbourne Airport said on its official Twitter account that airlines were experiencing difficulty checking in travellers for international services due to the outage of the Advanced Passenger Processing system.
About two hours later the aiport said the system was back up.
New Zealand airports were affected by a similar outage.
Airlines experiencing difficulty checking-in travellers for international services due to outage of Advanced Passenger Processing system.1/2— Melbourne Airport (@Melair) 21 May 2017
Update: The Advanced Passenger Processing system is now back online and all airlines are now able to process check-in.— Melbourne Airport (@Melair) 22 May 2017