Flight Bandaranaike International Airport departs from Colombo Bandaranaike International Airport at 13:05 and arrives at London City Airport at 20:00.
The flighttime is about 11h 25m. The distance travelled ("as the bird flies"): 9198 Km. So the average speed is roughly 806 Km.
There is an 4.5 hour time difference between Colombo and London