Australian airports back online after IT outage caused cancellations ...

Australia's airports are coming back online after customers faced mass cancellations and delays.

Sydney and Brisbane Airports are both back online and functional, with most major carriers, including Qantas and Virgin, able to process passengers after a slow start.

Regional airline REX has not been affected by the outage.

Some Jetstar flights are still being impacted by the outage, however, most will be able to operate today.

Passengers have been told to check with their airline if their flight will be affected. 

Airport and airline IT systems were caught up in the global outage on Friday, grounding planes and sending thousands of flyers' travel plans into disarray.

Cybersecurity firm CrowdStrike said that the issue believed to be behind the outage was not a security incident or cyberattack — and that a fix was on the way. The company said the problem occurred when it deployed a faulty update to computers running Microsoft Windows.

It wasn't until midnight that some Australian airlines were able to reassure customers that their systems were back in operation.

SEE AIRLINE STATEMENTS IN FULL BELOW

Jetstar appeared to be the most severely impacted.

The airline cancelled all flights in Australia and New Zealand until the early hours of this morning.

Just after midnight, Jetstar said its IT systems were finally "beginning to stabilise".

Flights on Saturday "are currently planned to operate as scheduled. Please proceed to the airport as usual," the airline said on its website.

Qantas said the outage hit services on its website and app, including booking and managing flights, online check-in, and retrieving your digital boarding pass.

"Qantas passengers should continue to travel to the airport for their upcoming flight. Check Flight Status for the latest information. We recommend you allow additional time," the airline said last night.

Anyone not travelling within the next 24 hours was asked to avoid calling the contact centre until another time.

The Australian cancellations are part of an estimated 1400 flights disrupted around the world on Friday, according to aviation analytics firm Cirium.

Airports across the country warned would-be passengers to allow extra check-in time and expect delays throughout the night.

By mid-evening, Sydney Airport said flights had slowly started landing and departing again.

"We have activated our contingency plans with our airline partners and deployed additional staff to our terminals to assist passengers," a spokesperson said. 

"Anyone travelling today should leave plenty of time to come to the airport and check with their airline regarding the status of their flight."

Melbourne Airport said Qantas and Virgin Australia had slowly started processing passengers and international flights were running as normal, aside from Jetstar and Scoot flights.

"Please check with your airline for flight updates," an airport spokesperson said.

Flights were still landing and departing at Brisbane Airport, where airlines were using backup systems to keep passengers moving. 

"Airport information screens are operational," a spokesperson said. 

"The Brisbane team will continue to keep you updated on any major impacts."

Perth Airport reported that check-in systems and processes were returning to normal.

"Flights are continuing to operate; however, delays and cancellations have been experienced," a spokesperson said. 

Adelaide Airport was also impacted.

It wasn't just air travel that suffered chaos either, with ground transport crews deployed across Sydney roads and other networks and working with police and emergency services.

Trains had been impacted but were returning to normal by early evening.

Even the train radio network in NSW had been impacted.

"There are no impacts to other modes of public transport and no impacts to the wider train network," a Transport for NSW spokesperson said.

"There are no adverse impacts to the road network and traffic lights are operational."

In Victoria, trains resumed after its communication systems failed, forcing the suspension of all VLine trains.

"Delays up to 120 minutes are expected as we work to restore services as quickly and safely as possible," a VLine spokesperson said.

Major stops like the Southern Cross saw crowds of people waiting for delayed and cancelled trains.

FULL STATEMENTS FROM AIRLINES

Jetstar

Our IT systems are beginning to stabilise, and flights on Saturday 20 July are currently planned to operate as scheduled. Please proceed to the Airport as usual.

There may be a small number of flights impacted due to operational reasons. If your flight is impacted, we will communicate directly to you using the contact details on your booking. You can check the status of your flight here.

We're continuing to offer flexibility for those customers who no longer wish to travel (free moves +7 days or voucher refund). Please contact us via Live Chat to discuss your options.

For customers impacted by flight cancellations on Friday 19 July, we sincerely apologise and appreciate this would have been a frustrating experience. The global software issue impacted multiple Jetstar systems, including the system we use to communicate to customers. Our teams are working on rebooking you onto new flights, and we will contact everyone whose flight was cancelled with updates on new flight times as soon as possible.

Thank you for your patience and understanding.

Qantas

We're experiencing technical issues due to a global third party outage impacting airlines and other businesses around the world. This is impacting services on qantas.com and the app such as booking and managing flights, online check-in, and retrieving your digital boarding pass.

Our partners are working to resolve the issue as soon as possible.

Qantas passengers should continue to travel to the airport for their upcoming flight. Check Flight Status for the latest information. We recommend you allow additional time.

If you're not travelling within the next 24 hours, please call our Contact Centre another time.

Virgin

Virgin Australia can confirm its operations remain stable following the impacts of a large-scale IT outage impacting businesses across the country.

We thank guests who were disrupted by this incident for their patience and understanding and will work with them to ensure they get to their destination as quickly as possible.