Flight Heathrow Airport departs from London Heathrow Airport at 09:50 and arrives at Mumbai Chhatrapati Shivaji International Airport at 23:40.
The flighttime is about 9h 20m. The distance travelled ("as the bird flies"): 8456 Km. So the average speed is roughly 906 Km.
There is an 4.5 hour time difference between London and Mumbai