Flight Tribhuvan International Airport departs from Kathmandu Tribhuvan International Airport at 07:35 and arrives at Istanbul Istanbul Atatürk Airport at 13:05.
The flighttime is about 8h 30m. The distance travelled ("as the bird flies"): 6302 Km. So the average speed is roughly 741 Km.
There is an 3 hour time difference between Kathmandu and Istanbul