Avoid flying with a tuba at all costs.
In other words...DON'T DO IT unless you absolutely have to have it and the only way you can get it there it to fly it along with you.
Call, email, send letters, whatever to anyone that has a tuba you could borrow or rent while you are at home. The pain of flying and the potential for damage make flying with a tuba a bad idea unless you have to have it and there is no other way (and there almost always is) to get it to where you're going.