Flight Haneda Airport departs from Tokyo Haneda Airport at 01:30 and arrives at Ho Chi Minh City Tan Son Nhat International Airport at 05:50.
The flighttime is about 6h 20m. The distance travelled ("as the bird flies"): 3910 Km. So the average speed is roughly 617 Km.
There is an 2 hour time difference between Tokyo and Ho Chi Minh City
THB
