The RR DB has one TG on the PAPD system labled "Interop," and it's in the clear...
Port Authority of New York and New Jersey Trunking System Profile
www.radioreference.com
But, let's face it: as fast as they make it 'in the clear,' they can encrypt it just as fast.
In any event, even if it's not clear, the PA has been wise enough to give one of their E radios to local FDs, at least at the GWB, anyway.
(Now that I think about it, it may not be an E radio, but a conventional radio not on the PD TGs)
As far as these "exercises" go at the airports, there's still not much to listen to. It's basically a drill and familiarization for the "outside agencies," most of which is done in face-to-face discussions, with the FDNY stretching one LDH (if that) while the Crash Crews pour water on...well, something that is burning or appears to be burning.
Then it's back to quarters for "OSHA-mandated nap period".