US Air; Manual wheelchairs, canes, crutches and walkers
On aircraft with more than 100 seats, US Airways has room for one typical adult-sided folding, collapsible or break-down manual wheelchair, cane, crutches or walker in the cabin’s priority stowage space, so long as it complies with applicable safety, security and hazardous materials rules. The priority stowage space will either be a closet or the back row of seats.
I've been told by some that the closet's are now built for jackets and the door will not hold anything heavy.