[Capt. Tom]

But the pirates from this area have kidnapped lots of people with construction skills, so perhaps they made their slave labor build a giant runway.

They could get away with a 3500 foot runway since the plane wold be low on fuel and not need a long runway to LAND.
Taking off, loaded with fuel is another matter and they would probably need a 5,500 foot runway. - tom

[Kirkwood]

How short of a runway for a fueled 777 to takeoff with no passengers or luggage?