Air travellers are facing ongoing delays as Jetstar continues to repair grounded planes due to a global software problem.
The issue led to the cancellation of 90 Jetstar flights in Australia on Saturday, with 34 of 85 of the company's A320/1 aircraft identified to have the anomaly.
Aircraft engineers were working to fix the issue which has left thousands of Australians stranded at airports around the nation.
"As of 3:30pm, 20 of the 34 affected aircraft are ready to return to service," a Jetstar spokeswoman said.
"We're expecting the remaining to be ready overnight, allowing flights to resume as planned on Sunday.
"However, there may be some flow on delays or cancellations on Sunday as the network fully recovers."
Engineering teams were deployed to airports primarily on the east coast to reverse a software upgrade on affected planes and carry out flight control checks before the planes are able to dispatch, Jetstar head of flying operations Tyrone Simes said.
Mr Simes said the airline was rectifying the situation, which took between two to three hours for each aircraft, and most repairs would be completed on Saturday.
"We're hoping to get it all done today and expecting the potential for some minor disruption tomorrow," he told reporters at Melbourne Airport on Saturday.
European plane manufacturer Airbus had ordered immediate precautionary action from operators of a significant number of A320 planes in service across the globe after discovering "intense solar radiation may corrupt data critical to the functioning of flight controls".
The issue was discovered after a US JetBlue flight made an emergency landing after the plane made a sudden uncommanded drop in altitude on October 30.
Jetstar said it would contact affected customers to advise of options, including refunds, and urged them to check their flight status before travelling to the airport.
Affected customers took to social media to document the long queues at airports in Melbourne and Sydney as authorities race to fix the issue.
Melbourne Airport chief of Aviation Jim Parashos said more than 6000 Airbus aircraft globally were impacted and the airport was working with Jetstar to help passengers get on their way.
"Being a weekend, schoolies, I've spoken to a lot of travellers that are heading up to Byron and Gold Coast. We appreciate their frustration, but they've been very understanding," he told reporters.
Sydney Airport said it was supporting Jetstar to resolve the issue, but noted all other airlines at the airport were operating as normal.
Qantas and Virgin Airlines have been unaffected by the software problem.