Funny you should mention that. I have a Calton case for it. I checked the weight and it came out to about 30lbs. No problem. We were flying United. Then, the night before we left, I checked their website and it said anything over 62 linear inches gets charged as oversize, which is a $200 upcharge! So, I thought about just leaving it at home, but I really wanted to bring it, so I decided to just give it a shot. I left Dawn and Xander at the check in and went to the park the car. When I called her from the shuttle bus to find out where to meet, she told me everything was checked at it was only $25! Apparently the staff was very helpful as she was wrangling all our stuff plus Xander. And he also played a role in charming them.
So, I had thought it was going to be $400 extra to bring it, but it turned out to be $50 total.
Sadly, Calton has apparently had issues since the founders sold the company. Mica said they'd talked to them a while back about getting some Alembic cases made, but they refused due to the length of the instruments. I'm not sure who I would recommend at this point, short of Jan-Al, who do make fantastic Anvil style flight cases. Those definitely put you over the weight limit, though.
I just looked up Calton, though, and it seems that they have moved the company to the U.S. and are making a big effort to get it together. It would be great if the quality has returned, because they really are among the best of the best. I have no qualms about what happens to the bass inside that case. I guess pictures are in order (I think Harry took some, maybe he can post them?).
I will also say that if you choose to have a custom case made by Calton or similar, be very careful about the template. The Starfire was done with an archtop guitar template. I placed the order through The Olde Town Pickin' Parlor in Arvarda CO. The guy who did it was casual to the point of arrogance. He insisted he knew how to do it and had done dozens of them (Are you sure that's right?Shut up, kid, I know what I'm doing.). I had a bad feeling about it and called Calton and sure enough, he'd screwed it up big time. So, I did the template all over again and it came out perfectly. Had I trusted this guy, it would have not fit and been another 6 month wait.
I would loved to have carried it on, but there's no way it would fit in an overhead bin.