Flight Imam Khomeini International Airport departs from Tehran Imam Khomeini International Airport at 03:20 and arrives at Istanbul Istanbul Atatürk Airport at 06:20.
The flighttime is about 4h 00m. The distance travelled ("as the bird flies"): 2527 Km. So the average speed is roughly 632 Km.
There is an 1 hour time difference between Tehran and Istanbul
IDR
