Hi Mechta, good to have you around. I have been looking at Skytrain's clues and what I can get out of them. Found many boom V-tail ultralights, many with similar 2-stroke engine and the same airfoil, pushers etc. Drones and no-drones. Tried several languages etc. I am sure when someone figures it out i'll be completely p****d not to have understood the obvious. Ever been there?