Qantas is facing two investigations for reportedly not warning staff last week before announcing sackings and closures.
The ABC reports that Qantas is accused of breaching safety guidelines and breaking industrial law.
Last week the airline announced it was axing 500 jobs and reviewing hundreds of maintenance positions after reporting a sharp fall in first-half profit.
The Engineers Union claims Qantas breached the guidelines by not warning employees of the changes before issuing the announcement.
A similar claim has been made by the Transport Workers Union.
The Fair Work Ombudsman's office says it will look into the matter.
Qantas says it complied with industrial laws and safety guidelines.