I can't find anything on the net about it, but I had a "eureka" moment while I was bored and was watching the landing of concorde that I recorded about a year ago. Hope this is right ben.

Concorde lands at a very high angle of attack compared to most planes, and the lift is generated by huge vortices which form over the top of the wing, vortices like tornados have very low pressure in them, so if a low aspect ratio wing's flow starts to seperate, the wing tip vortices get bigger and cover a greater percentage of the wing. This vorticy then allows the wing to fly for that couple of degrees more, horay!!!!!!