I've tried multiple times to decode the NAC on my BCD325P2, but all of the transmissions have been encrypted. Unfortunately, with the 325P2, if encryption is used, the NAC won't decode. I might have to dig out the BCD396XT and give that one a try because that receiver doesn't seem to have that issue.
If TSA is using UHF simplex I have found (at other airports) I have to be within a few hundred feet of the TSA checkpoint to pick up anything. Must be very low power.