Flight Noi Bai International Airport departs from Hanoi Noi Bai International Airport at 20:15 and arrives at Singapore Changi Airport at 00:35.
The flighttime is about 3h 20m. The distance travelled ("as the bird flies"): 599 Km. So the average speed is roughly 180 Km.
There is an 1 hour time difference between Hanoi and Singapore
