LIFE out of handcuffs appears to have turned actor Robert Downey Jr into a Superdad.

Breezing in and out of Sydney for just a few hours yesterday with his 11-year-old son Indio by his side, the restored Hollywood bad boy couldn't have been more attentive.

In near-matching outfits, carrying similar backpacks, father and son flew from Brisbane with Downey's fiance Susan Levin, stopping briefly before flying to Los Angeles.

Downey clutched Indio's hand from the terminal to a waiting cab, hugging him and whispering jokes in his ear when he got bored.

Clearly unaffected by his celebrity, Downey stopped for several fans, posed for photos and autographs with a big grin and spent much of the flight chatting away to Australian Idol TV show host Marcia Hines.

Indio, whose mother is former model Deborah Falconer and Downey's ex-wife of six years, had spent the past 10 days with his dad enjoying the fun parks of the Gold Coast.

Father and son had come to Australia to see Levin, the woman credited with Downey's turnaround from drug use and the woman he plans to marry next year.

Levin, the vice president for Joel Silver's Silver Pictures, has wrapped up work on the House of Wax which stars Paris Hilton.

Hilton was expected to return to the Gold Coast for an exclusive wrap party for the horror flick but did not show up at the weekend.