Dear Musician,
If you travel on airplanes, you know the hassle of 
  bringing an instrument. Some airlines are fine with you bringing an 
  instrument, some aren't. Some will accommodate you on alternate Tuesdays 
  following Ground Hog's day providing you're wearing their secret decoder ring, 
  and some will accommodate you if the flight attendant is in a good mood. And 
  some airlines that weren't a problem last month will demand you check your 
  guitar the next time you fly.
There's also the gig bag/hardshell case 
  issue. If your guitar's in a gig bag, airlines are more likely to let you put 
  it in the overhead compartment. But if they refuse to do that and you have to 
  check it, don't expect your axe to be in one piece when you get off the plane. 
  You can check the hardshell case, but bringing your guitar in a hardshell case 
  probably eliminates any chance of storing it in the overhead—if the airlines 
  indeed allow that.
Well, help may be on the way. The American 
  Federation of Musicians has taken up the cause of musicians who fly to gigs, 
  and Congress is debating a bill that would specify consistent guidelines for 
  carry-on instruments. According to the AFM: "If this bill passes, musicians 
  will be able to carry most musical instruments onboard and place them in the 
  overhead compartment or in a seat (if a ticket is purchased)." This is your 
  chance to make your voice heard. Here's a link for signing the 
  petition:
http://www.afm.org/departments/legislative-office/carrying-instruments-on-airplanesUntil 
  this (hopefully) becomes law, call ahead to the airline and ask for their 
  policy regarding carrying instruments on planes. If possible, get this emailed 
  or faxed to you so you have written backup should a flight attendant balk. If 
  the airline can guarantee that using a gig bag will let you place it in the 
  overhead, fine. Otherwise, you might need to pursue the hardshell case/checked 
  baggage route. But, note that the case that came with your guitar might not be 
  the best possible option. Case companies like SKB make guitar cases that look 
  like they could survive a small thermonuclear explosion, and while they're not 
  cheap, they're cheaper than replacing a vintage guitar.
Sign the 
  petition!