corrections needed first
VHHH is not a long hop, only 1680nm and mostly on airway A1 which by regional consent is westbound FL 280 300 340 380 400. Notice no FL360. And certainly no FL370 or 240 come to that.
My answer at a board would include West Pac South China Sea weather in general; what constitutes a Large Scale Weather Deviation and what doesn’t; show familiarity with the relevant AIPs and the terms FLOS, FLAS and No PDC; demonstrate local route knowledge and how good the Ops people are at planning; I’d cover fuel reserves in general and what my airline and/or the one I’m boarding for lay down. I’d express the view that for RJAA VHHH I’d be expecting FL340 all the way and a higher load factor than the fuel burn suggests. (It should be a popular route). The low fuel burn invites some mention of buffet if you outclimb the airframe capability. But if the winds took a turn for the worse I’d ask for lower expecting to be granted either FL280 or FL300. Providing that I wasn’t right on top of my ToD of course.
If you'd like to see more of what is involved drop me an e-mail.
Best Rgds
The "E"