Flight Tribhuvan International Airport departs from Kathmandu Tribhuvan International Airport at 17:00 and arrives at Delhi Indira Gandhi International Airport at 18:45.
The flighttime is about 2h 15m. The distance travelled ("as the bird flies"): 917 Km. So the average speed is roughly 408 Km.
There is an 0.5 hour time difference between Kathmandu and Delhi