Yeah depends on the Fair and what insurance they have etc etc.
Some will let you carry as long as it is tied in a way that makes them not easy to get out.
When I'm in the full suit and I do not have someone watching my back I started leaving the sword in the truck.
Drunk people do dumb things and I had an incident where a guy damn near ripped my sword carrier off trying to draw my sword to "test out my armor"
He nearly lost a few fingers when I closed my vambrace (elbow) on his fingers. He quickly let go. Normally this would have been just another "drunk guy" story but, at the time I was talking to a group of smaller kids and one of the little guys nearly got clobbered by the tussle. That was one of the last straws. The full plate suit weights in at over 90 pounds and I'm not a small guy so in full garb I'm around 350 pounds of sharp edges, metal elbows and knees.
And before anyone asks the million dollar question.
Yes, it is hot in the suit. (FAQ)
The trick is to wear a water soaked under garment made from cotton. Once the metal heats up the cotton and water wick the heat away and you don't over heat. Well unless you close the visor for more than 10-15 mins at a time. I have worn the full garb for 8-10 hours at a time in the Florida heat.