Strange Flight?

I was just surfing around for general flights and this one came up:

flightaware.com/live/flight/TN464AT

It says the plane is owned by AirTran, but it does not have the conventional flight numbers for a commerical flight or charter. I am assuming with the unique cities in its history that is is still in post-delivery (testing, painting, etc.) phase and has not yet begun regular service.

The only other guess is that this is owned by the airline, but is kept for corporate travel, etc.

Any ideas?

AT has had the plane for over 10 years. Used to be painted in the blue/white livery, but now is “unmarked”.

Your guess is as good as mine on what they do with it, but I’m pretty sure it would be charters because of the “TN”. Company execs don’t need that big of a plane anyway.