Flight Tribhuvan International Airport departs from Kathmandu Tribhuvan International Airport at 15:05 and arrives at Mumbai Chhatrapati Shivaji International Airport at 17:45.
The flighttime is about 3h 10m. The distance travelled ("as the bird flies"): 1397 Km. So the average speed is roughly 441 Km.
There is an 0.5 hour time difference between Kathmandu and Mumbai