Originally Posted by
pax britanica
At the end of the day are there really enough ULR routes in the world that make these sort of 19-20 hour sectors viable.
It's not rocket science. The airlines (and the manufacturers) know how many passengers currently fly between the ULR city pairs in question via hubs in Europe, ME3, Asia, etc.
By taking a view about the proportion of that traffic willing to pay a premium for direct, non-stop service on those routes, it's possible to derive the potential market for a ULR aircraft of a given size.
Of course whether that market is big enough to support one or two new types/variants remains to be seen.