The air force would like to close down two long established bases at Richmond in NSW and Laverton in Victoria, distribute their units to other bases and have the government dispose of the real estate.
But RAAF chief Air Marshal Leo Davies insists it's a decision for the federal government and, if approved, could still be more than a decade away.
Richmond, northwest of Sydney, wasn't in a fighting state and if it was maintained would need investment of hundreds of millions of dollars to bring it up to a proper standard, he said.
Rationalising defence bases is a long-running issue, which invariably produces strong reactions from affected communities and their MPs.
For the RAAF consolidating bases saves on long-term upkeep and by having a few large bases, gives personnel a more stable career path, without need for frequent moves.
However proceeds of any sale would go to consolidated revenue.
RAAF Richmond, founded in 1925, is now home to 37 Squadron, which flies C-130 Hercules transport aircraft and temporary home to 35 Squadron, which will relocate to RAAF Amberley once facilities for their C-27J aircraft are constructed.
RAAF Laverton, now part of RAAF Williams Point Cook, is home to the defence language school and other academic and technical training units.
"Air forces that we could close, re-establish capabilities that exist because of those bases at other locations and be more efficient," he told reporters in Canberra.
Laverton units could go to city of Melbourne, Point Cook, Amberley and RAAF Edinburgh in South Australia. Richmond units could end up at Amberley.
Air Marshal Davies said this was a methodical process and timelines remained quite opaque.
"Most of these are not ready yet for government decision but we are on the path," he told reporters.
"I am thinking this is 15 years away."
Should RAAF Richmond be closed, defence would seek to maintain an airhead capability somewhere in the Sydney basin. That could be at Kingsford-Smith, Badgerys Creek or Richmond if it reverts to a civil airport.
Defence Minister Marise Payne said she wanted to clarify the government's position on the two bases.
"I would like to make it clear the government is not considering the closure of either RAAF Base Richmond or RAAF Base Laverton," she told parliament.
