JessicaTam, in Australia are not airlines 'paranoid' about not allowing passengers on board while refuelling occurs? Likewise, happy to be corrected but that's my occasional experience in previous years.
The now largely discontinued practice of international airlines operating triangular routings (such as DEL - SYD - MEL - DEL or the same for MNL, or vice versa, to name two, one on AI, the other PR) invariably saw passengers required to alight if say the flight first called at SYD but the passengers' destination was MEL.
QF suggests that the delayed QF63 will arrive in JNB at 2042 tonight. It will be interesting to see how long it takes to detach the engine from VH-OJS. For the engineers among us, is it a complex procedure or (in engineering or maintenance challenges) relatively straightforward?
I assume that this aircraft, OJS will be the one heading back to SYD tonight South African time, as surely placing the engine on the defective B744 currently sitting on the JNB tarmac would take quite a while.
Should there be further unanticipated delays, then the SYD curfew may again come into play. The flight back (nonstop) is normally a trifle under 12 hours.