Qantas subsidiary Jetstar has cancelled dozens of flights for September because it has too many unsold seats on its planes.
The airline says the changes to its schedule affect fewer than 10 flights a week. It runs some 540 flights a month.
The airline says the cancellations are for September only and basic scheduling remains unchanged.
Jetstar says all affected passengers have been contacted and the vast majority were rebooked on other flights within a couple of hours of their original booking.