By Neve Brissenden in Sydney

Qantas engineers are gearing up for another round of strikes during the peak Christmas travel period after walking off the job on one of the busiest days of the year.

Long-running wage negotiations between a consortium of unions and Australia’s largest airline have stalled, culminating in a more than 24-hour stoppage beginning on Friday morning.

Another strike has been scheduled for next Friday and the unions’ Qantas Engineers’ Alliance has signalled more industrial action could follow if there is no deal on pay and conditions.

The alliance, made up of members from three unions, said almost 500 engineers across major Australian airports walked off the job, although Qantas said only 160 engineers were actually rostered on during the strike period.

But despite falling on what was expected to be the busiest day of the year for domestic travel at Sydney Airport, there were few signs of cancellations or significant delays for Qantas flights or at other major locations on Friday.

The airline said the strike had little effect on its pre-Christmas operations and, five hours after the strike began, 97 per cent of its flights had departed on time.

“We have put a number of contingencies in place and extra resourcing on the ground to ensure our customers get away as planned,”  a Qantas spokesperson said.

“As always at this time of year our aircraft are full and airports are busy, so we urge customers to give themselves more time to get through security and get to their aircraft.”

The airline had refused to buckle to the union’s wage demand of five per cent extra per year with a 15 per cent first-year increase.

Qantas said the unions had been looking for over 40 per cent in pay increases over three years, which was not sustainable.

In return, the airline was offering wage rises and other improvements that would result in take-home pay increasing by an average of 15 per cent over the same period.

Major airports have been preparing for bumper travel periods during the potentially disrupting industrial action.

Almost six million passengers are set to travel through Sydney terminals between Friday and January 27, while Melbourne is preparing for its busiest summer of international travel on record.

The strike comes after a six-week pause in industrial action during which the parties resolved to continue negotiations over a new enterprise agreement.

The union consortium, made up of the Australian Manufacturing Workers’ Union, Australian Workers’ Union and Electrical Trades Union, said Qantas forced the walkout by refusing to negotiate.

“Workers were asked by Qantas in good faith to not take industrial action as a commitment to resolve bargaining,” Australian Manufacturing Workers’ Union secretary Steve Murphy said.

“For six weeks, Qantas has shown they cannot live up to their own values – they lied … workers are feeling disrespected by the behaviour of Qantas and we all know how that feels.”

Unions have been negotiating for a deal with the airline since April but were unable to reach agreement before the existing arrangements expired in June.