Qantas has reached an agreement with one of the three unions at the centre of the protracted industrial dispute that led to the grounding of the airline's fleet.

Qantas and its licensed aircraft engineers go before Fair Work Australia today, having settled on key issues following arbitration. However, the union failed to secure the construction of an A380 maintenance hangar in Australia as part of its fight for members' job security.

The agreement marks a significant milestone in the bitter dispute that prompted Qantas to ground its fleet in October, but the airline remains at loggerheads with its ground staff and long-haul pilots over conditions, job security and pay.

Earlier this year, the federal secretary of the Australian Licensed Aircraft Engineers Association, Steve Purvinas, predicted a drawn-out dispute with Qantas and promised to "bake them slowly" with industrial action.

But, since Qantas took the unprecedented step of grounding its aircraft, all parties have been forced into binding arbitration.

Of the three groups in dispute with Qantas, the engineers were considered the most likely to resolve their differences. It could still be some weeks, however, before an agreement is finalised by the industrial umpire.

"We will be submitting an agreed workplace determination to Fair Work Australia that represents a good deal for Qantas and its 1600 licensed engineers," a Qantas spokesman said.

"All the key issues have been addressed through the arbitration process with the licensed engineers' union and we are very pleased to have finally reached an agreement. It does not include any of the claims that would have restricted Qantas in making the changes needed to compete in the global aviation industry."

Mr Purvinas declined to comment ahead of today's Fair Work hearing.

The airline's disagreement with its long-haul pilots and baggage handlers is set to run into next year, with Fair Work Australia to hear the dispute with the Australian and International Pilots Association in June.

Meanwhile, a legal challenge by the long-haul pilots against Fair Work's decision to terminate their protected industrial action against Qantas will be fast-tracked in the Federal Court and could begin as early as February.

The vice-president of the pilots' union, Richard Woodward, said it would rather negotiate an in-principle agreement with Qantas than go to workplace determination. 'Hopefully as [Qantas and the union] go through the process of refining our claims we might come to an agreed position,' he said.

The international arm of Qantas was "shrinking considerably"' as jobs were sent offshore. "We're concerned about the future of our young pilots,' Mr Woodward said. 'We'd hate to see them made redundant from Qantas while [the airline] expands overseas.'

The dispute between Qantas and the Transport Workers Union, which represents baggage handlers, is set down before the full bench of Fair Work in March, with job security remaining a key issue of contention.

"We remain committed to the separate arbitration processes with the pilots' union and Transport Workers Union and are hopeful of reaching a positive outcome in each case," a Qantas spokesman said.