I've had two rather expensive guitars trashed by airlines. I am very surprised that you can't just put a trumpet in the overhead compartment? I've been able to fit acoustic guitars (in hardshell cases) in overheads (mostly on international flights tho). I've found that if you ask in advance, that a lot of the time you can have a steward or stewardess store you instrument in their coat closet. This may have changed now, due to the post 911 stuff, although I had no problem doing this shortly after 911. The best bet is to have your stuff insured! If you don't, you'll have to jump through a ton of hoops just to get the airline to pay out $250US for a $2200US guitar! I learned the hard way! It's also hard to find a quality guitar when you are short on time and have to play a gig in Latvia!