went back over land with passengers in the back, seem like somebody would have had some kind of kagcontaccould the plane go missing if it collided with some other smaller jet? of course it could. but another plane would be missing, too. and we would be hearing about that from somewhere. so, wolf, when you stack up all these possibilities, we don't have an answer. but when you compare what we know with the possibilities, this is why so many of the aviation community are saying those three facts it tell them that it was a deliberate maneuver to turn the plane and go somewhere else. whether it was done unduress because of terrorists or mechanical be problems, they believe it turned for a reason. although it still is just another step on the way to explaining what actually happened in the real pock kit. >> as you point out, still a theory being investigated. tom foreman, thanks for that report. let's get more now with a retired pilot. is there any reason ever why a pilot would want to turn off a transponder? >> well, if purpose tly trying be not observed. similar to the one hijacked and taken