Britannia
Rob-Ginger. "Not many here who would have flown on a Bristol Britannia" ???
I serviced them in the early 1960's, along with Connies when they transited Adelaide. Also serviced and flew in Bristol Freighters, something which even fewer would have done I suspect.
As for the 180 degree turn and descent from 10000 metres to 7000 metres
the turn would simply to back-track toward Alice Springs and the descent may well have been the OEI driftdown altitude for the weight and ISA conditions prevailing.