Flight Dulles International Airport departs from Washington Dulles International Airport at 08:23 and arrives at Sint Maarten Princess Juliana International Airport at 12:35.
The flighttime is about 3h 12m. The distance travelled ("as the bird flies"): 1754 Km. So the average speed is roughly 548 Km.
There is an 1 hour time difference between Washington and Sint Maarten