LHR-HKG-SYD routings take longer than LHR-SIN/BKK-SYD, though. I saw a discussion recently about this, in the context of QF's new LHR-HKG-SYD service and why it take so much longer despite the fact that turnaround time at HKG is about the same as turnaround in SIN and BKK. I infer that aircraft must fly more track miles if going via HKG.