On Sept 11, 2001, all civilian airplanes were grounded, and all inbound international flights were directed to other countries. Two airplanes, one belonged to Korean airline, one Chinese airline, were ordered to land in Canada. The pilots did not understand the instruction and kept coming. F-16 were deployed and ready to shot them down if they did not follow the fighter pilots lead. Fortunately when F-16 showed up and flipping their wings, the Korean and Chinese pilots followed the fighter planes and landed in Canada.