Originally Posted by
CXhk
On top of that, utilisation as per your list is crazy. Aircraft aren't specifically allocated to routes. They rotate throughout the network based on their departure/arrival/maintenance times. If you honestly think Cathay has no spare aircraft, then you're hugely misguided. Go down to Haeco and check what's hanging around the apron there.
I think the poster was trying to roughly account for where all the 77G/77H frames are being used, not where each exact frame goes.
For example, CX139/138 requires one 77G frame to operate daily (not necessarily the same frame each day) - CX139 departs HKG at 0900 and the return CX138 arrives HKG at 0515 the next day.
A more complicated example, for frames 1-3 ORD/LHR:
Frame 1: CX806 departs HKG at 1155 on day 1, CX807 returns to HKG at 2020 on day 2, CX255 departs HKG at 0035 on day 3, CX252 returns to HKG at 0655 on day 4, CX806 departs HKG at 1155 on day 4, repeat.
Frame 2: same as above, starting on day 2.
Frame 3: same as above, starting on day 3.
Of course, like you said aircraft are rotated throughout the system based on maintenance needs and regional route flying as well. The post was a good back-of-the-envelope approximation for how the 77Gs and 77Hs are being utilized on long-haul routes, and it shows that, at least for the routes I highlighted above, they are being pretty well-utilized with no spare frames sitting around for days as a back-up. Of course, there is still some downtime, which is why you see 77Gs and 77Hs on regional routes. In the ORD/LHR example above, 5 hours between CX252 and CX806 is a bit tight, but given an extra few hours, the frame could easily fit in a MNL run.