FILE--Passengers pass through security before re-boarding their US Airways Flight 3441 after it was diverted to the Tri-Cities Regional Airport in Blountville, Tenn., Monday, Aug. 28, 2006. The commuter airplane flying from Philadelphia to Houston was diverted after a threatening note was found on board, authorities said. None of the 56 passengers aboard the flight was injured, and no bomb was immediately found, authorities said. Canada will always be at the mercy of the United States when it comes to airport security in the post 9-11 world, but that isn’t necessarily a bad thing for passengers, says the head the Canadian Air Transport Security Authority. (CP PICTURE ARCHIVE/AP Photo/The Johnson City Press, Dave Boyd)