Flight Heathrow Airport departs from London Heathrow Airport at 21:25 and arrives at Bangkok Suvarnabhumi Airport at 18:05.The flight has a short stop at Phuket. The flighttime is about 14h 40m. The distance travelled ("as the bird flies"): 11001 Km. So the average speed is roughly 750 Km. There is an 6 hour time difference between London and Bangkok