I've seen this. It's a possibility. Is it hard to attached and detach? I'm seeing mixed thoughts on whether or not I need to detach it before putting it in the airplane seat.
The new versions have pop-off wheels, so you can leave the frame attached to the carseat while belted in the seat.
Even the old versions car be left on when belted to the seat, but it leaves minimal space for the kid's legs.
It's very easy to detach/attach. Two large bolts screw into a bar that goes into the "hollows" on the back of the carseat.