I noticed this very short hop at Flightaware:CKS 208 (Calitta Air)KJFK - KEWRThis flight lasted 18 minutes (including, apparently, one spin) to cover the 20 or so miles, and I was curious why other transport means weren't employed, as in my mind using a 747 isn't the most economical way to transport something such a short distance. I don't live in that area, but I do know there are rivers separating these locations.The only reason I can come up with is if there are size or weight restrictions on the bridges that the cargo involved would have violated.Does anyone have any other thoughts?

Could be the reason you stated or it could be a reposition leg to pick up another customer's property.

Or it was a repositioning flight to pick something up or maintenance.It doesn't always have to have cargo inside to fly.Looks like you beat me by a minute, Travis :)

Yeah, repositioning also makes sense. For some reason, my brain got stuck in the other mode... DUH! I was only considering drop-offs and not pick-ups.

Maintenance flight, or training, was/is my guess.