I don't know where you've been lately but here in the USofA one is no longer allowed to bring a scanner on to an US Air Base where a military air show is taking place.
If it is a generic air show where military aircraft will be then yes, but NOT on a US air base. I know that this was true as of three years ago & probably remains true today.
Oops, I misread what this topic was, you can delete it here.
pk