when it comes to Iaito and air travel, I find hard shell gun cases with egg foam inside by Flambeau work great. Pretty inexpensive, $20 to $30 and have been sturdy. Also faily light weight.
Room enought for two iaito or an iaito plus a bokken plus a shoto.
This looks like or may be the same model as I picked up at a local sports store.
I always start with, "It's not a gun. Sporting goods, no moving parts."
if it's for aikido and need to carry a jo, this is too short. But then when traveling, I can often borrow a jo locally.