I own two Caltons, one for my M-36 and one for my D-18GE. Haven't flown with them yet, but they do insulate well against summer heat and humidity and have also protected my guitars during long winter drives. For flying, I recently bought a Voyage-Air OM and was able to bring it into the cabin (on the regional SD-LAX puddlejumper, I zipped it apart and stored the computer compartment of the case beneath the seat so that the guitar section would fit in the smaller overheads). I just ordered their dread too. That's the only guitar with which I'll fly.