And what part of an airline cockpit is in the public square? Last I looked the airplanes were private property. The law, but not FAA policy, already allows for pilots to be armed. Seems the "Public Square" spoke on the issue sometime ago. It's just that unelected bureacrats didn't go along with their supposed masters. All they need to do is run the pilots through the shooting and safety part of the sky marshalls course, and let the Airlines buy them the proper ammunition.
Then of course there is the little issue of the pilots being part of the group called by the term of art "the people" in the Constitution. That group whose right to keep nad bear arms is not be infringed, per the terms of the second article of amendment to that documnet.
I want a job where my employer pays my ammo bill.