Flight Changi Airport departs from Singapore Changi Airport at 08:45 and arrives at Mumbai Chhatrapati Shivaji International Airport at 11:55.
The flighttime is about 5h 40m. The distance travelled ("as the bird flies"): 3418 Km. So the average speed is roughly 603 Km.
There is an 2.5 hour time difference between Singapore and Mumbai
