[FourtySeven]

I was thinking of this possibility yesterday. But it doesn’t seem reasonable because in today’s post-9/11 world, any plane flying without a transponder will be shot down. The terrorists have to know this.

[justlurking]

But it doesn’t seem reasonable because in today’s post-9/11 world, any plane flying without a transponder will be shot down.

No, that's not going to happen outside a war zone. There are too many benign causes for a transponder malfunction.

A plane without a transponder will be investigated. But, it won't be shot down unless there is an unambiguous indication of a threat.

[Husker24]

I wonder why pilots even have the ability to shut off the transponder in the first place.