Tigerair Australia is considering flying into Richmond in a move that would turn the RAAF base into Sydney's de facto second airport until the federal government builds a new one.
Flying into the airforce base would tap into western Sydney's rapidly increasing demand for flights and provide a convenient base for budget flights for many Sydney residents, including those from growth suburbs in north-west Sydney, Penrith, the Blue Mountains and Blacktown.
Multiple sources have said the budget airline, controlled by Virgin Australia, has been in high-level discussions to use Richmond as a second destination for its services to Sydney.
The federal government has said it will ''explore the possibility'' of allowing airlines to use Richmond for limited domestic flights.
But it still thinks western Sydney needs a new second airport larger than Richmond which, at 280 hectares, is a relatively small site on a patch of land above the flood plain.
Tigerair also has plans to double its size by 2018 as it tries to stem losses of $60 million a year and repair its reputation after the grounding of its fleet in 2011. It plans to boost its fleet of A320 passenger jets from 11 to at least 23.
It is believed to be interested in using Richmond because it wants to capture a larger slice of western Sydney's market, which is growing faster than the eastern side of the city.
''It would appeal to those out west,'' one source said.
But an airport at Richmond requires investment in a terminal and facilities to cope with passengers.
A report last year by the federal and state transport departments estimated it would cost about $144 million to build minimal apron and terminal space for about a million domestic passengers a year.
If Richmond is upgraded to take about five million passengers a year, as many as the airports at Cairns or the Gold Coast , the cost would be at least $500 million, the report said.
Richmond has often been touted as a likely airport for spillover flights from Kingsford Smith at Mascot and most suited to budget airlines, such as Tigerair and Jetstar.
Tigerair declined to comment, saying only it was ''reviewing our forward strategy'' in the wake of Virgin buying a 60 per cent stake.
Tigerair would require government approval to fly to Richmond. And it would also be likely to trigger Sydney Airport's right of first refusal on operating any second airport in Sydney.
The federal Transport Minister, Anthony Albanese, who has previously said he would start discussions on using Richmond for domestic flights, said : ''Richmond is currently a defence-only airport and therefore Tiger or any other airline is not permitted to use Richmond RAAF base.''
The Mayor of Hawkesbury, Kim Ford, said a senior public servant from Mr Albanese's department briefed the council on the ''possibility of using [the airport] for limited domestic use'' a fortnight ago, but had not been specific about when or how this would happen.
''People in the Hawkesbury want infrastructure to go with that,'' Cr Ford said. ''If they've got to put up with all the noise and traffic that goes with an airport, they've got to have upgraded roads, upgraded train services.''