this is awesome, I really like it. I hold a JAR-PPL(A) and the cost of hiring a simple Cessna 152 is just ridiculous (same goes for buying) - bearing in mind that it's technology from about 30-40 years ago... I am amazed by the operational costs of the SD-1. Just out of interest, what fuel does the engine run on? Avgas, Mogas (never really looked into UL)?