Sad news for the K8J: My test flight alerted the EASA, which consequently contacted the french aviation authorithy about it. They have decided to revoke the K8J permit to fly. The reason stated is that a jet engine is not allowed on an ultralight. However, the french regulations don't mention the type of engine, only the number and power are limited. That's what I'm going to explain to them. They didn't give any other reason to terminate my permit to fly, they simply stated that this type is not allowed. I don't know how it will turn out or even if I have a chance to fly again. But I know that I became a jet pilot for a couple of minutes and put the EASA on alert, and that's a win in my book. Apparently, the K8J was made out of Rearden Metal. I want to thank the HBA community on more time for helping me achieve my goal.