Flight Chhatrapati Shivaji International Airport departs from Mumbai Chhatrapati Shivaji International Airport at 09:45 and arrives at Kathmandu Tribhuvan International Airport at 12:25.
The flighttime is about 2h 10m. The distance travelled ("as the bird flies"): 1397 Km. So the average speed is roughly 645 Km.
There is an 0.5 hour time difference between Mumbai and Kathmandu