Flight Don Mueang International Airport departs from Bangkok Don Mueang International Airport at 06:40 and arrives at Hanoi Noi Bai International Airport at 08:30.
The flighttime is about 1h 50m. The distance travelled ("as the bird flies"): 606 Km. So the average speed is roughly 331 Km.
The best day to arrive at Bangkok is Wednesday and it would be best to avoid Friday, as prices are on average 202.87% higher than on Wednesday. (Average prices, based on 164742 datapoints.)
We have a lot more statistics for flights FD 642 and between Bangkok and Hanoi.