| Loosen the strings before you get on the plane! The combination of the pressurized plane and pressure from the strings can do bad things to the neck of the bass.
I've known some guitarists who got away with bringing their guitar on board as hand luggage, but even they don't always get away with it. One friend tells an interesting story about an army dude at an airport in Pakistan using his machine gun to point at the guitar and repeat over and over "No. It's luggage"! That's an extreme but it it shows that you're not 100% guaranteed to get your bass or guitar on as hand luggage. So if you intend to go ahead with the idea, have a backup plan.
I've never know any bass players who got away with it. I've always put my bass into one of those a moulded plastic hard cases. Even though I've not had any problems yet, I'm saving up for a proper flight case. I usually check it in as normal luggage but they usually make me take it over the the "oversize luggage" section.
I also use a luggage strap with a combination lock on it to stop people opening it and playing the bass (or worse). I'll know immediately if anyone has tampered with it.
Oh and don't forget that the weight of the bass counts toward the total luggage weight you're allowed to bring on to the plane. So either travel light, or be prepared to be charged extra. You'll probably come home with more than you left with, so account for that in your calculations too.
Most importantly HAVE FUN!!!!!!!
__________________
Composite speaker cab enthusiast.
| 
