How does Qantas fly on chip fat?
13 April 2012 Last updated at 16:43 BST
The Australian airliner Qantas has become one of the first to fly a commercial aircraft using biofuel.
On Friday a flight from Sydney to Adelaide went off without a hitch and Qantas says a complete move to biofuels could reduce airline carbon consumption by up to 60%.
Duncan Kennedy reports.