Flight Noi Bai International Airport departs from Hanoi Noi Bai International Airport at 21:20 and arrives at Xi an Xi'an Xianyang International Airport at 01:10.
The flighttime is about 2h 50m. The distance travelled ("as the bird flies"): 543 Km. So the average speed is roughly 192 Km.
There is an 1 hour time difference between Hanoi and Xi an