The Many False Hijackings of 9/11 http://911blogger.com/news/2011-04-10/many-false-hijackings-911#comments

Reports about these false alarms have revealed extraordinary circumstances around some of the incidents and bizarre explanations for how they arose. For example, it has been claimed that the pilots of one foreign aircraft approaching the U.S. set their plane's transponder to transmit a code signaling they had been hijacked simply to show authorities that they were aware of what had been taking place in America that morning. [1] Another aircraft reported as transmitting a distress signal while approaching the U.S. was subsequently found to have been canceled, and still at the airport. [2]