WHBM
I think Cathay Pacific might raise an eyebrow about this - always plenty of pax on Europe to Hong Kong flights heading on there.
I don't know how I forgot Cathay - I used them between Hong Kong and Seoul late last year. But there were only three of us off my BA flight and two of us plus a family of five transferring to BA on the way home. I know the numbers because both connections turned out to be much tighter than planned and we were escorted as a group from one flight to the next.