Airservices Australia has announced it is sacking 900 workers, creating fears for safety in the sky.

Airservices - a government-owned air traffic control, navigation and emergency services company - claims the job cuts will affect back room support staff only.

It is party of reforms under the ‘Accelerate’ program, which will see Airservices' workforce reduced by almost a quarter over the next year.

But insiders have told reporters that they have received no clarification about how the Accelerate program could affect the security of the nation's skies.

Unions are seeking an urgent Fair Work Commission hearing to stop the job cuts, with lawyers from the CPSU, ETU and Professionals Australia requesting an immediate suspension of the Accelerate program.

Airservices says it engaged in comprehensive consultation with the industry before the job cuts were outlined.

“We are not reducing the size of our operational and rostered air traffic control or aviation rescue firefighting staffing,” the spokeswoman added.

The CPSU wants an urgent meeting in Canberra.

“When you get multiple faults happening that's where you get into trouble. So being able to fix faults as quickly as possible is really important,” CPSU president Alistair Waters said.

“That's why those highly skilled technical staff are just so critical.

“One of the reasons why you absolutely need to have very high standards and low risk margins in aviation is because when you're talking about aviation risk, you're talking about catastrophic risk.”

The Aircraft Owners and Pilots Association of Australia (AOPA) has gone further, calling for the resignation of Airservices chief executive Jason Harfield.

“It's utterly disgraceful ... I find it almost incomprehensible that the senior executive team of this billion-dollar organisation have not been able to secure the futures of these people who they are now asking to leave,” AOPA's executive director Ben Morgan said.

“The people that are going to feel this the most are the low end. This is going to be another exercise in the top end of the organisation band-aiding their problems and their mistakes by asking the people at the bottom end of the chain to sacrifice their day-to-day work.”

Airservices says every application for a voluntary redundancy, or consideration of an involuntary redundancy, will be assessed individually.

“Appropriate actions have been taken to ensure that the implementation of the Accelerate program is managed in a way that assures operational safety is considered throughout the life of the change program,” an Airservices spokesperson told the ABC.