Originally Posted by
Boghopper
I think they don't want such passengers in their airspace. For example, on a couple of flights from ADD to IAD we had to stop in Rome soley for the purpose of rescreening the passengers. That was the conditon of allowing a "direct" flight from ADD to the U.S. (and if you saw the clown school that passed for security at ADD, you'd understand why).
The ADD-IAD flight stops at FCO because of the altitude of ADD. Take off for a non-stop flight from ADD would add unacceptable load restrictions to the flight.