Incident to the Airbus A330 registered VH-EBC operated by Qantas on 15/12/2019 at Sydney [Investigation led by ATSB / Australia]

Preliminary data based on the notification from the Australian authorities:

During cruise, the green hydraulic system failed and the crew returned the aircraft to Sydney. During taxi, an issue with the nose wheel was detected and the aircraft stopped to wait for towing. When the APU was selected, the cabin filled with hydraulic mist resulting in the crew deploying the slides.