Put them in your weapons case and take them as "carry on", and never refer to them as weapons; they're pieces of exercise equipment. This should work as long as you're not travelling with Iaito. That's what I do, but then I'm in the military and I just show the inspectors my ID and walk on through. Yet another perk
Another option is to purchase a hard sided case for snow skis. You could pack your weapons case inside of it and then travel with them as "checked baggage".