An industrial drama has flared up at the Royal Australian Navy's only air station because of a lack of public servants to maintain vital radars and other air traffic control equipment.
A cease work notice was issued at HMAS Albatross in Nowra for three days last month because of safety concerns.
It shut down regular air traffic control services at an airfield which hosts 130 flight movements daily.
It followed a "cut to the bone" reduction in technical staff looking after the equipment, according to one union.
It is believed concerns about a lack of personnel had been frustrating staff for the past year.
Mostly military aircraft used HMAS Albatross, the nation's largest operational Naval establishment.
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Australian Manufacturing Workers Union NSW secretary Tim Ayres said the safety concerns were not surprising given staff numbers had been cut to the bone.
Eight technical staff had been whittled down to two, he said, although the Defence Department said seven technical staff had reduced to three.
"Two people are straddling much longer than the average working day," Mr Ayres said.
He was sceptical about how long it would take to fill the shortage.
"It takes 6 months to train one of these people," Mr Ayres said.
A Defence Department spokesperson said the shortfall was caused by a lack of interest during recruitment.
"To manage the risk associated with this shortage additional uniformed Air Force technical personnel have been augmenting the maintenance workforce while a more permanent solution is pursued," the spokesperson said.
"Risk is further managed by confining the maintenance focus to key items including radar, navigational aids and communications equipment and by reducing (air traffic control) operational hours."
The Australian government is already experiencing a drought of experienced technical staff to support defence operations.
While the technical staff at Albatross were part of the Navy workforce and not the Defence Materiel Organisation, a leaked internal audit of the DMO shows staff there might be signing off on equipment authorisations without the necessary skill level.
"On October 20 the Australian Public Service work, health and safety representative issued a cease work notice (at Albatross) in accordance with the Workplace Health and Safety Act 2011," the spokesperson said.
"[Air Traffic Control] services were ceased, however the airfield continued to operate utilising a common traffic advisory frequency.
"This is a normal procedure at many Australian airfields."