Originally Posted by
gailwynand
There is a lot of traffic going from IAD to SGN, to the extent that NH has Vietnamese signage at IAD. Not sure if UA has (or will have) an aircraft capable of serving that route, though.
IAD-SGN would be too low yield if sold as a nonstop, but IAD-HKG on 787 then continue onto existing HKG-SGN tag with 737 may work.
I also see HKG-KUL and HKG-CGK tags viable if using 737s/757s.