Jetstar Asia faces a $20 million bill to replace two engines after one of its A320s flew through volcanic ash.
Flight 114 left Perth on Friday, February 14, at 2.25am and flew through the ash cloud before arriving in Jakarta at 5.50am.
The A320 was grounded after the flight and is being inspected by Airbus and the makers of the engines.
A Jetstar spokesman said there was "no warning from air traffic control or notification" that the flight would hit the ash cloud.
The eruption of the Mt Kelud volcano in Java last week caused many flight cancellations and delays between Perth and South-East Asia.
Virgin Australia cancelled all flights to Bali, Phuket, Cocos and Christmas islands.
The ash cloud over Java reached an altitude of 55,0000ft — well above the cruising altitude of 40,000ft.
The most extraordinary encounter with an ash cloud was in June 1982 when a British Airways 747 flying from Kuala Lumpur to Perth with 263 passengers and crew had total engine loss after it flew through volcanic ash caused by the violent and sudden eruption of Mt Galunggung in Indonesia.
Capt. Eric Moody and his crew cleared the engines of ash by putting the 747 into a steep dive.
The engines were restarted when the aircraft reached about 12,000ft.