. So is it correct to say that the 787 has a load factor of around 20% on the MELB/PER/MELB legs of this flight?
No. I don’t know what the total loads are between Perth and Melbourne on the QF9/10, but it’s also sold as a domestic sector, and connects fairly well for Perth pax to the LAX/SFO services I think. These pax aren’t included in those BITRE stats for Melbourne to London, or Perth to London (and back).
The additional 20% odd are just the Pax traveling all the way from MEL - LHR (via Perth), or vice versa, as that is the QF 9/10 service. The PER - LHR numbers are pax originating in Perth, or joining the service from elsewhere.