Qantas Airways likely faces several more weeks before its fleet of six Airbus A380s can return to service threatening to squeeze its capacity as it heads into the busy Christmas season.
The delay also indicates Rolls-Royce will need more time than Qantas expected to resolve the engine issue, which led to a November 4 oil fire and explosion on a Qantas jet with 466 people on board shortly after it departed Singapore for Sydney.
Qantas immediately grounded its fleet of Airbus A380s – the world's largest passenger plane with a list price of around $350m (£218m) each –pending an investigation, but has no deadline on the process after several initial indicative deadlines by the airline passed.
"It's a very complex process and it's still in the early stages," a source told Reuters.
"I expect Rolls-Royce and Qantas are still several weeks away from putting together an action plan and its documentation," said the source, who asked not to be named because they were not authorised to discuss the issue.
Rolls-Royce and Qantas shares have suffered since the accident, both losing more than seven per cent since 3 November.
Rolls-Royce, which has said little publicly about the investigation, last week announced that the failure was confined to a specific component in the turbine area and it would replace the relevant module according to an agreed programme.
A Qantas spokeswoman said the airline had no time schedule to put the A380 back in service and it remained engaged with Rolls-Royce to resolve the issue.