don't most terrorist attacks take place inside the planes? 29M on the test? does anyone else think this is stupid?

It is really not possible to launch a terrorist attack from within an airplane anymore. The last few attempts were quelled by the rest of the passengers or check-in security. (There is a reason why you have to take off your shoes and cannot bring large quantities of liquid aboard, other than to harass you. Anyone else remember why?)

That means if terrorists are going to take down an airliner (always good for headlines) they have to find some other way do it. Man-portable SAMs are one way. And, courtesy of their friends in Iran, I am sure that terrorists can get some of these.

The problem the government faces in providing such defenses is one of "damned if you do -- damned if you don't." If they provide them, some joker always complains about the cost and reliability, especially after nothing happens. If they do not provide them, citing cost and reliability, and an airliner gets shot down then some joker (generally the same one that would have stated the whole thing was "stupid" had the government provided them) will complain about how the government lacks foresight, and fell down on the job.

The real problem with evaluating the effectiveness of such defenses is that often, as a result, the dog does not bark. Knowing that airliners have a defense against SAMs, terrorists are less likely to try to make such attacks, and their sponsors are *much* less likely to give them the toys necessary for such attacks. By fulfilling their function by dissuading attacks they create the impression that they were unnecessary.

Sorry about the triple post. The comment feature hiccuped.

Right On Mark. After the first post its almost appropriate to double yours.

When will these jet airliners have their own cloaking device?

The problem, rob, is that just one successful attack with a SAM could create ripples that could really destroy the airline industry - especially if it occurred in a western country rather than some area already viewed as dangerous.

What will be REALLY interesting is what happens when the detectors go off - in the military they signal the need for evasive maneuvers - in a civilian aircraft and folks get drinks spilled or worse. The need for folks to be seated and belted during takeoff and landing approaches will be even stronger.