The Adam 500 was a neat concept. The composite fuselage was supposed to save weight but came in over 1000 lbs heavier than if they would have used aluminum. Full fuel useful load was under 160 lbs, and with 2 engines, it was fairly thirsty so it needed a lot of fuel to go places. It would have been a nice competitor for the Mirage/M350 for those that liked having 2 engines in a piston pressurized cross country plane. They could have solved the weight issue with 2 turbines, but then feeding 2 turbines with only 230 gallons of fuel, would have given it anemic range. Was close to a great design, but came up short on the engineering side.