How long does it take to get to Vietnam from heathrow airport?

OPTION 1: 16hr 40min London Heathrow (LHR) to Ho Chi Minh City (Saigon) (SGN)

LHR - DOH Qatar Airways Flt 002 Dep 09:30pm 29May,Fri

DOH - SGN Qatar Airways Flt 688 Dep 07:30am 30May,Sat

Flight Duration: 15hr 35min; Layover Time: 1hr 5min; Total Trip Time: 16hr 40min