As far as walking on the plane and walking off the plane, that is a whole different situation than waiting in a half hour immigration or security line. On the AA website, you have the option to pick "i can walk short distances" or " I need wheelchair assistance onto the plane", something to that effect. I always get a wheelchair when I have to deal with immigration, but I don't need it to get on and off a plane. I can walk short distances, but if I have to walk more than that, it is extremely difficult for me, and I cannot stand for long periods of time. Even when walking, I need extra time to get onboard, so it is very helpful to me to board early, to be able to do that, without people jostling me. But I don't need a wheelchair for that.