Just to double check, this is domestic, right? It shouldn't matter, but I always give myself some extra time for internati onal -- who knows what they have to do for passpor t stamps or whatever. If you're domestic, not-che cking bags, and have everything in order, arriving at 5:30 should be okay, but it'll be tight if you 're far. Make it 5:15 and you can grab a cup of c offee, I'd say, to be on the safe side.
...and I'm not really sure why or how my font chan ged, sorry if that throws people