I've used my black small keep all for air travel no problem, carried with me on the plane. I stow it under the seat in front of me, but *DO NOTE* that I've felt a little iffy seeing that I need to "bend" the shoulder straps slightly since they don't "collapse" on their own.. if that makes sense?? Because if I lay it flat on its "back", the shoulder straps poke my feet. I can only completely fit it under the seat by putting it somewhat upright and manipulating the straps a little. Now, I tend to use my oversized mulberry alexa for such purposes.... I guess there are some pros to it not holding its shape dissolving into a puddle!