Hi
All you guitarists should think yourself lucky, just slacklen off a few strings, get it into the coat locker if your lucky, fiddlers can usually get it in the overhead locker.
I play the piano accordion, every time I fly I have to take apart the bass stuff it with foam, put it in s huge flight case and put it in the hold...then of course hope it comes back in one piece!!
The clod hold temperature does the reed no good and the bass buttons usually fall under even though I stuff it.
Cheers, Sam