Probably on TG BKK-MEL in October 1989. My travelling companions also smoked, but elected to sit in non-smoking, and simply came back and stood next to me when they wanted one.

Smoking on Australian domestic flights had been banned in 1987. Bans on international flights to/from Australia were progressively introduced over the next few years.

A self-imposed ban on myself smoking commenced early 1998 (and remains in force).