My knowledge of the Amish is obviously rather slim but why can't they take a plane but can take the bus? I know I that they shun most modern technology suite h as cars etc but I would have thought if they can't take a plane that they also wouldn't be able to take the train.
From what I gathered they live in communities spread across a small area of the state. They get on and get down at small towns that amtrak makes a stop, those towns are not served by airplanes. Not sure about technology thing though, never felt comfortable asking them about that :D.