It is just a saying ... I'm really not sure why you are so hung up on a saying. Of course I do not mean a tank can fly. I just mean an IED has the power to hurl a tank into the air, which is why a MRAP is needed to counter these threats .Fighter jets are shot/blown out of the sky because they fly, tanks don't fly so they can't be "blown out of the sky" they can be blown to pieces, or blown to smithereens or blown out to space, etc. etc.