Qantas says it has made a careful assessment of weather conditions and will go ahead with today’s flight to Jakarta.
The airline had been considering cancelling its service from Sydney due to the risk of ash clouds from the recent eruption of Mount Merapi.
Several other international airlines have cancelled flights to the Indonesian capital because of fears that the ash could damage aircraft engines.
Mount Merapi, on Central Java, first started erupting on October 26, a day after a tsunami killed more than 400 people in a remote area off Sumatra island.
The volcano, which is 430 kilometres from Jakarta, has so far killed more than 120 people.
It is still ejecting plumes of ash and superheated gases with molten debris falling nearby.
About 200,000 people have been evacuated from the area.