I'm amazed this aircraft flew for 10 years! That is a long time to study something. Not including crew and fuel, it could carry 1,500 lbs., which may not seem like much but this was a prototype with really small inefficient engines, and it could takeoff vertically like that. You could also put the design characteristics of any aircraft into it, and it would fly like that. It became the world's first real time simulator! A modern version with composite technology, upgraded impeller design, and a ballistic parachute recovery system could really be something. That is this crafts big drawback, it does not auto-rotate and it does not glide if something goes wrong. Nothing did in those 10 years though, nothing that caused it to crash, (the first one was a loss due to a technical mess up, not a design flaw).