I have flown many times with my touring bike, and always put the bike with rear wheel in the frame , fork turned, front wheel tied agains top tube, handlebars twisted through the spokes, in a regular size bike box.
I just checked with Delta airlines regarding their requirements for bicycle transport and was told you have to pay $100.00 for anything with total dimensions (l+w+h) over 62" with a maximum of 80" total. Any regular bike box (about 56"x28"x8") is easily over 90" total. They only way (mathematicaly) to make is work is take a 44"x24"x12" box, in other words make the box thicker to gain more volume, and also take the rear wheel out of the frame to shorten the bike.
What do you think? I hear Delta airlines is not very bicycle friendly but this should work. It surprises me this is neccesary since the bikeboxes I used to get from the airlines where huge, you could even leave the front wheel in the bike.