The pogos fall off upon take off. If they don't, they try to shake it off and it it still won't fall off it is an emergency and they have to come back and land. The U2 was/is a PITA for controllers especially in Osan, Korea or Prince Sultan Air Base, Saudi Arabia with a single runway. All the barriers need to be taken down and all other traffic needs to be held until they can get off the runway. At Osan, we weren't allowed to say "U2" so we used "priority" instead. After years of using "priority" you would think that the North Koreans would have figured it out.
They always sent up a Lt. Col or above to act as SOF (supervisor of flying, usually a captain or major who sits up in the tower and runs emergency checklists with the pilots..not a controller) when the U2 landed so he could over-ride the current SOF if any landing priority situations existed.
Not a fan of the Dragon Lady.