Qantas engineers will stage industrial action indefinitely to protest against working conditions they claim may affect the safe operation of the airline.
The engineers' union, the Association of Professional Engineers, Scientists and Managers, Australia (APESMA), says the move may ground a number of Qantas planes and those of the company'slow-cost operator Jetstar.
Bans on overtime and out-of-hours call-outs will start in Sydney at 5pm on Friday (local time) and last until 9am on Monday, the union says.
The action will re-commence from Monday at 5pm until Tuesday at 8am and continue on the same daily pattern indefinitely.
APESMA director Catherine Bolger said Qantas had resumed talks over the disputed working conditions but negotiations had been unsuccessful.
"All they are asking for is proper recognition of their role and their commitment to the airline(s)," Ms Bolger said in a statement.
"They also want management to address what is a serious issue of fatigue caused by long hours and after-work call-outs."
The professional engineers at Qantas form a small part of the airline's engineering workforce but must sign off on any significant maintenance work before planes are allowed to fly.
Ms Bolger said some professional engineers had been called to address complex issues with less than five hours sleep since their last shift.
The engineers were committed to ensuring planes were properly maintained and safe to operate, she said.
"The industrial action may, however, result in some Qantas and Jetstar planes not being allowed to fly, causing disruptions," Ms Bolger said.
Attempts were made to contact Qantas for comment but were unsuccessful.
A Qantas spokeswoman later said the thrust of the enterprise bargaining agreement (EBA) negotiations had been about wages.
The union wants a 30 percent increase over three years, which Qantas has deemed "completely unreasonable", she said.
The spokeswoman also said airline safety had not been an issue and any such discussions would not apply to EBA negotiations.
Qantas is committed to further negotiations with the union and has promised that the planned industrial action will not impact services.
"Contingency plans we have in place will ensure that there will be no disruptions to operations or services," the spokeswoman said.
"And there will be absolutely no grounding of plans as a result of the industrial action that's being taken."
