Pilots and air traffic controllers fear safety will be at risk if Airservices Australia pushes ahead with a proposal to merge some of its locations.

The ABC has learned of plans to consider removing controllers monitoring airspace in Sydney, Adelaide, and Cairns, and hub them in Melbourne and Brisbane.

Airservices Australia, which manages air traffic control in the country, is looking at consolidating some of its Terminal Control Units (TCUs).

Once planes take off, they are monitored by TCUs while flying over busy metropolitan areas around 60 kilometres from the airport.

Once they reach less congested airspace, they are then handed over to "en-route controllers", who are already based in Melbourne and Brisbane.

Internal staff discussions obtained by the ABC reveal controllers are deeply concerned about the move.

"The benefits of local knowledge, industry contact, career variety... cannot be underestimated," one controller wrote.

"Disaster recovery and the other benefits of decentralisation are not to be scoffed at.

"I think the idea of moving remote TCU's into major centres is flawed, and any 'paper' savings will be utterly negated by reduction of service provision, loss of employee satisfaction and reduced overall capability within the company," said another.

Local knowledge important, say controllers

One of the recurring themes among controllers is the importance of local knowledge - something former pilot Clark Gibbons knows all too well.

Nearly 20 years ago he was flying a Cessna 210 near Canberra when its engine failed.

He put his faith in air traffic controllers because he was surrounded by blinding cloud.

He said he requested to land on Lake George, which he knew to be virtually empty.

"They then gave us the [directions] - and when we have popped out of the cloud we've crashed into the side of a hill with no advice from them that we were not being put over Lake George," he said.

"Ten seconds would have been the maximum amount of time... from seeing the trees, seeing the hill, having nowhere else to go but crash into the hill."

Mr Gibbons and his other passengers suffered serious burns in the crash.

The controller was based in Melbourne because Airservices Australia had consolidated the region's Terminal Control Unit.

The Bureau of Air Safety Investigation (now Australian Transport Safety Bureau) found that the air traffic controller guiding the plane was not familiar with Canberra.

"Although he received advice from another controller who was familiar with the Canberra area, the approach controller was not so familiar," the report said.

"The limitations of the radar display, which depicted Lake George in general terms, prevented the controller from being certain of the aircraft's position with respect to terrain features."

Airservices raised similar plans around a decade ago, but eventually rejected them because the business case was marginal.

"It is appropriate that some of our ATC [Air Traffic Control] Operations groups remain decentralised especially when the financial case for centralisation is marginal and these moves result in dislocation for staff and their families," the 2006 letter to all staff from then-chief executive Greg Russell read.

In a statement to the ABC, Airservices said no decision had been made, and the current suggestions were a review of all the available options.

It said that centralising operations could improve career development and help remove duplicated infrastructure, equipment and maintenance.

"Safety is Airservices' number one priority and a detailed safety analysis will be undertaken to consider any potential risks and effectively manage any future changes if they are actually made," it said.

Labor's transport spokesman Anthony Albanese said he believed it was about "cost cutting".

"We shouldn't be cutting costs when it comes to aviation safety," he said.

The former transport minister's Western Sydney electorate is near Sydney's airport.

"Common sense tells you that if you live and work at the actual airport, which is Australia's most significant airport - it's the most densely populated area in Australia - there's a reason why you want to have the air traffic control around that airport controlled from Sydney airport rather than from a remote location in Melbourne or Brisbane," he said.

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