Flight London Gatwick Airport departs from London London Gatwick Airport at 08:55 and arrives at Rome Leonardo da Vinci–Fiumicino Airport at 12:30.
The flighttime is about 2h 35m. The distance travelled ("as the bird flies"): 1725 Km. So the average speed is roughly 668 Km.
There is an 1 hour time difference between London and Rome
IDR
