The civic leader, carrier Regional Express (Rex) and the Regional Aviation Association of Australia (RAAA) all noted the federal cabinet's decision to sign off on a site for a second Sydney airport yesterday after decades of debate.

While they welcomed any opportunities the $2.5 billion project may bring they said it was essential Dubbo and similar cities continued to have flights into Sydney's Kingsford Smith Airport at Mascot.

Work is expected to start on the Badgerys Creek airport in 2016 and the first flights are expected in about a decade's time.

Cr Dickerson said the detail of the flights into the second airport would determine its impact on Dubbo.

"We've got to make sure we still have access to Sydney's CBD and the international airport," he said.

The mayor said there were times when an airport in western Sydney would be useful to Dubbo passengers.

It had been easier for him to drive to a meeting near Penrith this week rather than take a plane, but extra flexibility would be welcome, he said.

"Ideally we'd have flights to both," he said.

Government legislation protects regional slots at the existing Sydney airport.

Cr Dickerson said he was not aware of any discussion to change that, but if there was, Dubbo City Council would take up the matter with the federal government.

Rex has advocated for ongoing protected regional slots in the past and yesterday maintained they were critical to the sustainable provision of NSW regional air services.

"The guaranteed access to Sydney airport for regional NSW recognises the importance of Sydney airport's role as an essential transport hub for regional NSW which is why this has been enshrined in legislation," a Rex spokeswoman said.

"Rex welcomes initiatives that help to reduce capacity pressures on Sydney (Kingsford Smith Airport), however it is imperative that NSW regional communities have continued guaranteed access to Sydney airport."

RAAA chief Paul Tyrrell said a second Sydney airport would have to be a stand-alone airport with a full range of services.

"It would have to grow its own market," he said.

Mr Tyrrell, chief of the industry body for regional aviation, said there were many discussions to come before the first flight boarded.

"It's up to business people and the council to assess, but I would have thought if current services were not affected and it was a chance to have more services, it's a good thing for places like Dubbo," he said.

"The question for Dubbo is 'do we want to go to western Sydney'."