What's wrong with changing after security? I've never heard of any restriction . . . seems pretty obvious they want you in uniform so they can see you're crew, and so the pax don't bitch. Once the show is over, who cares?
Who knows with these idiots. Here's my example.
Flew a busted sequence, one leg to hotel, DH home next am.
Splattered crew meal on pilot shirt. Next am I wore the usual uniform clothes except switched dirty shirt for Polo shirt, left hat in bag.
My bags go through the xray machine, alerts are sounded, TSA supervisor makes a tactical approach to my kitbag convinced he has discovered a tactical nuclear weapon. Well, not really, it was my bottle of hot sauce.
After his initial disappointment that it wasn't a nuke, and he wouldn't be getting the Congressional TSA Medal of Honor, he remained aggressive despite by profuse apologies for my 5:30 am oversight of Federal Code. the nuke, I mean the hot sauce, would be confiscated.
Not wanting to lose my favorite bottle, In a humble and respectful way, I suggested that he could hold it for me, I could exit, put on my scummy shirt to complete the "street legal" uniform, enter a again and everybody is happy.
It was then I was told, (with attitude), that if I did that, I would be arrested and charged with "by passing and evading airport security". It was a new one to me.
Of course I withheld my next thought that came to mind that I was already evading airport security by dealing with his "village idiot" arse.
My bottle of hot sauce became a POW of the TSA.
Here is some more lunacy. My next trip through the same airport security, I was legally clearing "behind the lines" with an item that was more dangerous than hot sauce, but less than a nuke
In the room was a box of 15-20 bottles of rum, confiscated from the unwary arrivals from the cruise ships. I mentioned that I hope it ends up at the TSA Xmas party, TSA (good guy) rolls eyes and says a Hazmat company actually has a contract for guys in protective suits to collect it and destroy it. I kid you not. Imagine what the bill is for that.