Outfit has been around for ages. Typical charter/management type outfit. Good reputation from what I hear.
Used them for a back-up not long ago.
They've got a couple Hawkers, an old DA-20, I think an old Gulfstream or two, and a Westwind. I think all those are based in ITH.
I believe they also have aircraft on cert. not based in ITH.
Check out their website.
<http://www.flytac.com/index.php>