Excuse me, but it was you who raised the issue of the switched-off transponders, claiming that this act "...made them even harder to track..."

At any rate, right on cue, you include your personal tale of a failed transponder, and pose the rhetorical question: "What were they supposed to do, shoot me down because my voltage regulator failed and took out my battery? "

No, the Air Force shouldn't have shot you down because:

a) You weren't hundreds of miles off course.
b) You weren't flying a fully fueled passenger jet.
c) You weren't bearing down on the nation's largest metropolitan areas at top speed.
d) You weren't one of four passenger jets doing the same thing.

Your example is irrelevant.

To sum up, I've presented four examples which clearly evidence that the Secret Service, USAF and other elements of the defense establishment were well aware of the threat posed by hijacked jetliners.

Never addressing any of these points, you attempt to skirt the issue by rehashing the same ol' bogus cop-out, that gee, we didn't think they'd ever do anything like THAT.

Which, to repeat myself one final time, is poppycock.

I'll just note in closing that my assumption that the United States Air Force has the mission of defending the nation against air attack is hardly out of date.

sp