A little late I know but it's usually not a problem at least with an acoustic. No reason why it should be for you....some airlines have rules saying you need to inform them beforehand. I would recommend taking it in hand luggage and lining up for your seat early so you can hog luggage space which was meant for other people too. You might feel a little uncomfortable because of the glares of your copassengers but at least you get your guitar home safely!
And surely youíll buy your pint cup !
and surely Iíll buy mine !
And we'll take a cup oí kindness yet,
for auld lang syne.