Olie (and other interested parties):
Here is my recipe for flying with an instrument. YMMV.
I have a Calton case for Woody, so if going in the cargo hold is in the cards, I needn't worry. The just bring a gig bag and hope they let it on method is too nerve-wracking for me.
I try to get to the airport a little early. ALWAYS carry it to the gate, don't check it in with regular baggage.
I find there are some planes that will accommodate the case in the overhead, and some that won't. On the latter, there is often a closet for the crew or first class in which an instrument will fit. A sympathetic flight attendant can put it there.
I just try and carry the instrument onto the plane until someone tells me I can't. Then I try to sweet talk them into it. If that doesn't work, I gate check the guitar. At least then it doesn't go through the conveyor belts, multiple handlers, and increased chance of loss that most checked luggage endures. Also, at most airports, the gate checked luggage is returned to you as you leave the aircraft instead of going through baggage handler purgatory and winding up on the big merry-go-round.
One word of caution: I try to do this only on non-stop flights or, at least, direct flights (with a stop, but the same plane). The thought of checking my guitar and then changing planes mid-trip scares the heck out of me.
I've seen that Gator is advertising a new line of ATA approved cases that appear to be lighter than the typical anvil. I have an anvil-type case for my Fernandes/Alembic. It's great for protection, but I can't even pretend to carry it on - just too big. Hope this helps. I'd love to see the new baby in person! This is going to be BIG FUN!
Bill, tgo