I suggest taking off your kilt pin, unless you have soldered it on - or otherwise permanently affixed it - and it won't come off. Put it in your checked luggage because TSA probably will not like it being in your carry-on.

Likewise, don't wear a sghian dhub.

You can search through the forum for 'kilted flying' kind of threads too. There have been a couple of those in recent memory.

Have a fun, safe trip.