You have four options:

1) Buy a Calton case, or maybe a Pegasus. (Those cost a good deal more, new, than the present value of your old Yamaha.)

2) Travel with a guitar that you consider expendable, in a normal hard case, packing it carefully with a lot of padding inside the case, especially around the headstock.

3) Don't travel by air.

4) Don't travel with a guitar.

Sorry I'm not more help. But yes, airline luggage handlers go into a blind rage at the sight of a guitar case. I don't know why. Maybe a guitar player bit them at some point.

Peter.