The U-2 is so difficult to fly that it requires external sensors to land. AKA another pilot racing down the runway in a chase car radioing instructions to the pilot in the plane.
It has only two landing wheels--one in the front and one in the back (called bicycle landing gear). The chase car tells the pilot what to do to keep the plane balanced on two wheels as it goes down the runway. At the end, as it slows down, it reallly wants to tip over. Before it can, ground crews run up and put wingtip stanchions with wheels on them under the wingtips to complete the landing gear so it can taxi. Really amazing
https://jalopnik.com/5537629/the-140-mph-chase-cars-of-the-u...