Australia's aviation safety watchdog wants Qantas to improve the maintenance of its planes, but has stressed the airline is safe.
Over the past month, several Qantas flights have been cancelled or delayed due to engine problems and in July a 747 was forced to make an emergency landing in Manilla when an oxygen tank exploded.
An audit by the Civil Aviation Safety Authority has found the airline's maintenance procedures are not up to its own standards.
However, it says the deficiencies it has found are not linked to the airline's recent safety incidents.
The Australian Manufacturing Workers Union says that over a period of time they have seen more work sent offshore, so they are genuinely concerned.
Federal Transport Minister Anthony Albanese says the authority will now carry out two further audits of some Qantas planes and their service records, as well as the airline's overall maintenance procedures.
Qantas says it will work with the authority on maintenance improvements.