Australian airlines struggled to move a backlog of tens of thousands of passengers on Wednesday after an ash cloud from a Chilean volcano, which had grounded flights across the country's eastern and southern states, cleared.
The ash cloud has circled the earth twice to disrupt Australian airlines for a second time, costing Qantas an estimated A$20 million before the latest disruptions and the tourism industry more than A$15 million in two weeks.
Australia's Bureau of Meteorology's Volcanic Ash Advisory Center said long-term modeling suggested the ash cloud would not pass over Australia for a third time and disrupt airlines.
Volcanic ash can be extremely dangerous to aircraft and cause engine failure or engine damage.
Qantas said it had resumed flights from Melbourne and Sydney, the country's two main terminals, while Virgin Australia had also resumed flights. Qantas low-cost subsidiary Jetstar and discount carrier Tiger Airlines were all also gradually resuming flights.
"There's possibly some hope that Thursday will start to return to normal," said Civil Aviation Safety Authority spokesman Peter Gibson.
The majority of international carriers continued flights to and from Australia on Wednesday, with airlines including Singapore, Thai, Etihad and Emirates landing in Sydney.