If you know you are traveling by air, and you only have carry on luggage, I suspect that you could TAKE OUT the knife blade in your Leatherman and just put a spacer there.
Then you can put the blade in when you come back...
I picked up a couple of the Lowe's Task Force mini multi-tools on clearance for $1.00 each after last Christmas.
Just for fun I took out the nail file and put in a spare house key.