Didn't hear that one, good to know. China Clipper: The Age of the Great Flying Boats by Robert Gandt talks a lot about the Postmaster General and those postal contracts in the US. I came away from the book with a distaste for Pan Am given some of the stunts they pulled. It basically details that having the postal contract was the only way to make regular flights profitable in the early aviation years. To the point, many routes started as postal only.