Qantas Airways chief executive Alan Joyce says authorities need to end the talk and start building a second Sydney airport.
Mr Joyce says he supports federal Transport Minister Anthony Albanese's bid to deliver Australia's most populous city a second airport to cope with the expected growth in air traffic in the years and decades ahead.
"Minister Albanese and Qantas have been talking pretty closely about what the requirements are and we will continue to have a big input in that dialogue," Mr Joyce told reporters on Friday.
"Anybody that does any projections would know that we have to have a second Sydney airport for the economic development of Sydney, NSW and Australia.
"We have been talking about it for a long time, we just need to get on and do it."
Mr Joyce was speaking at the launch of Australia's first commercial flight powered with biofuel, a Qantas Airbus A330 which left Sydney bound for Adelaide.
While Canberra has been pushing hard for a second airport to ease the strain at Mascot, NSW Premier Barry O'Farrell is opposed.
Mr O'Farrell prefers to expand Canberra airport and introduce high-speed trains between Sydney and the national capital.
Sydney Airport argues there is plenty of capacity at the airport, pointing to the more efficient use of existing gates and larger aircraft being flown, as well as the arrival of new airlines such as Air Asia X and Scoot.
The chairman of Sydney Airport Holdings Max Moore-Wilton has said the airport, which handled 35.6 million passengers in 2011, would have no issues with capacity until 2045.