So, as you can see from the law, if there is no one screening the passengers entering the terminal, it is not a secure area and you can legally carry there. I would be careful if I were going on an interstate trip because other states may make the whole airport off limits. I remember when there was a move to do that in Atlanta.Sec. 46.03. PLACES WEAPONS PROHIBITED. (a) A person commits an offense if the person intentionally, knowingly, or recklessly possesses or goes with a firearm, illegal knife, club, or prohibited weapon listed in Section 46.05(a): ...
(5) in or into a secured area of an airport; or ...
(c) In this section:
(1) "Premises" has the meaning assigned by Section 46.035.
(2) "Secured area" means an area of an airport terminal building to which access is controlled by the inspection of persons and property under federal law.
BTW, this is why I consider most of our airport security to be a joke. I can take of a small to medium size plane from lots of public non-airline served airports and land at the airline served ones. With some planes, I can load a full squad of men with lots of weapons and ammo and take over anything at the major airport I want to.