The union representing most of Qantas' professional engineers, the Association of Professional Engineers, Scientists and Managers (APESMA), has been involved in a stand-off with the airline over conditions and pay.

Yesterday, 98 per cent of the professional engineers voted in favour of industrial action, claiming talks with the company had broken down.

The engineers will meet today to decide what action to take.

Qantas employs a total pool of 5500 engineers, with 190 of those professional engineers.

Qantas spokeswoman Olivia Wirth said the airline was "disappointed" by the union's decision.

"Qantas has not walked away from the negotiating table," she said.

"They're asking for 30 per cent pay increase over three years, which is unreasonable.

"That includes a 21 per cent increase in the first year."

Ms Wirth said if the professional engineers do decide to take industrial action, Qantas has contingency plans in place and does not expect any disruption to operations or customer travel.

"Qantas will not be grounding planes," she said.

"Obviously, safety remains a priority and this will not be compromised in any way, but we will not be grounding planes."

APESMA director Catherine Bolger said the dispute centred on a demand for pay parity with other workers and on the out-of-hours work required to maintain the airline's fleet.

"The fact that 98 per cent of professional engineers have voted in favour of action demonstrates the depth of feeling of their frustration," Ms Bolger told Macquarie Radio on Friday.

"We're hopeful that (Qantas chief executive) Alan Joyce will recognise the crucial input our members have in maintaining the airworthiness of the Qantas fleet."