With the switch over to UHF P25 for the Transportation Security Administration (TSA), there have been some airport locations that are revealing some new frequency allocations. I recently discovered a new repeater pairing in Detroit (DTW). They are using 407.7000 / 415.7000 MHz, with a NAC of N13E. I had not seen this pair of frequencies in use at other airport locations yet.
I also heard from a reader who confirmed 411.3375 MHz, N0D2 in use in Rochester, NY (ROC).
I am posting updates on new frequencies and NACs on the TSA page here:
http://mt-fedfiles.blogspot.com/p/tsa-frequency-updates.html
As more airport locations start using the new Motorola UHF radios, some new frequencies are bound to show up, so keep searching!