I was being an ATC this evening and noticed a rather strange behaviour of the UI AND/or the game. Basically it was a C17 It was flying very low above sea level and asked for landing clearance. I went into the menu but there was no Cleared for takeoff option. The game treated the plane as if it was standing on the ground but it was not. I zoomed in on the plane and gears were up and the plane was still in the air. Really weird.