I just reenlisted for Fort Liberty and I am projected to be in a non-airborne unit. Could I still get airborne school TDY en route?

It may be too late to request Airborne TDY En Route, but I bet you can get Airborne after arriving to Liberty. Speak with your Talent Manager to see what your options are. Worst case is you submit a 4187 after you get to Liberty.

When you get to 19th Replacement -- they'll ask if you want to go airborne -- Get in shape, don't quit, feet and knees together. Airborne All the Way!

Most likely you won't be able to. I have been at Liberty a few times. Slots are given to units that have positions coded with the airborne ASI. HRC will not let you get a school enroute unless it is required at your new unit. Once you get there you may ask and your unit may get a shot. A lot of it is about the availability of slots and how commands handle those requests. A lot of times you can get it as a re-enlistment option but you didn't get it in your contract. I would still try when you get there.