What about a "secondary flight controls" achievement? (Land an aircraft without any primary flight control surfaces) For example, on one of my first B-29 sorties I went into a dive and promptly discovered that all my flight controls didn't like that airspeed. Fortunately I also found that the that the rudder, aileron and elevator trims still exerted some slight control authority. I was unable to get the nose up at first so I dumped the bombload and hoped for the best. I eventually leveled out at 5k over enemy territory and warded off a couple would-be opportunists. Autopilot would not hold level. I then set myself up for a 15 miles straight in to the nearest friendly field. By using differential engine power, and toggling flaps (still functional),landing gear and even the bomb bay doors (which apparently do factor into the aerodynamic modeling) I managed a landing just right of centerline and saved the perks. That was probably my most achievement worthy landing of all time and couldn't help but think of it when I saw this post.