Australian travellers are warned, there could be major delays to both domestic and international travel next Friday.
Aviation firefighters are preparing to walk off the job.
The United Firefighters Union says understaffing is putting travellers at risk.
All firefighters across every airport fire station will stop work for four hours on the 9th of December.
it wants Air Services Australia to hire more firefighters.
In a statement, it says there are 2,500 passengers boarding flights without firefighters around every single day.
It is unclear whether airlines will reschedule or cancel flights as a result.
