There are plenty of charters that use UPS to fly Saturday/Sunday from PIT to popular vacation destinations. In fact, for a while you could buy a seat directly from UPS -- UPS Airlines -- in PIT, but that didn't pan out.

As per WN, I didn't know they were in the charter business. But for example, I have seen a Sun Country plane in PIT and I might be wrong about this one but I even think an Alaska Airlines plane in PIT.

The other, less probable suggestion about WN is that they are considering PIT service. While I don't consider it realistic, supposedly the Allegheny county executive (where PIT is) is now actively courting more competition for USAirways in PIT. I wish him good luck but expect the worst

24 people on a plane? I hope that PanAm isn't grounded before it takes off, since every other low-fare entrant into the PIT market, except Vanguard, has pulled out in a couple of months.