Flight Noi Bai International Airport departs from Hanoi Noi Bai International Airport at 20:55 and arrives at Bangkok Suvarnabhumi Airport at 22:45.
The flighttime is about 1h 50m. The distance travelled ("as the bird flies"): 593 Km. So the average speed is roughly 323 Km.
The best day to arrive at Hanoi is Friday and it would be best to avoid Thursday, as prices are on average 180.5% higher than on Friday. (Average prices, based on 2175656 datapoints.)
We have a lot more statistics for flights FD 645 and between Hanoi and Bangkok.