If small means able to get it into an overhead compartment on an airplane than any O, OO, OOO or OM size guitar will do. I travel a fair bit by air and have never had a problem getting my om size in an overhead bin. If the plane is truly a puddle jumper then they take your guitar away at the plane and give it back to you at the bottom of the stairs at your arrival. I use a Calton case which is slightly larger and it still fits in the overhead, except on L1011's. Weird bins on those. I'm also a fairly large man and the small size feels fine to me. Too small (Backpacker, etc.)and you're not playing a guitar, you're playing a toy.