Very interesting. I Googled "AMT Olympus turbine" for more info on the little jet engines. AMT builds small jet motors for model aircraft. I was amazed at how "cheap" they are. 3 to 5 thousand euros is not cheap money, but compared to other small jet engines, they are very "cheap", indeed. Most small jet engines used in little planes (remember the BD-5 jet of James Bond fame)are Auxilliary Power Units, that are usually used to start larger engines, and can cost 6 figures. If one had the engineering ability to design it, and the balls to fly it, one could build a very fast little jet, using 4 of these baby engines, with an engine cost of less than a lot of piston powered home built planes. No doubt, people are looking into it.