relax...there are a lot of armed ppl running around airports these days, you just don't see em. airport is one of the MOST secure places you could possibly be. it super hard for armed citizens to get in, and even if they managed it somehow, there are lots of trained security officers who are armed to deal with the miscreants.
it's not like you see at Euro airports, where there are these hard-eyed Israeli type guys n girls running around with automatic rifles, tho...which is OK by me.