You need to cover the weapon up... I believe for swords they do
have...
Then buy those bags specially made for swords... make sure that the
bag has a big big labelling titled Wu Shu in Chinese. Sling this
around with you. Don't chuck it in your bag or luggage if it fits
in. Should help you get past.
If you can't past, at the most drink coffee with police, then ask
your master to verify for you.
If you aren't going alone, go with a group of martial artist
friends. They would carry weapons as well... so it will be
safer...