Flight Dulles International Airport departs from Washington Dulles International Airport at 17:45 and arrives at Lisbon Humberto Delgado Airport at 06:05.
The flighttime is about 7h 20m. The distance travelled ("as the bird flies"): 7596 Km. So the average speed is roughly 1036 Km.
There is an 5 hour time difference between Washington and Lisbon
