Regards rolling T/O: What wind speed for Go/NoGo for a rolling T/o on say a 15 degree slope?
For a rolling takeoff, the wind required depends on the length of the takeoff slope. You just have to reach flying airspeed before you’re in the bushes, and the headwind is the airspeed you start with. In theory, 18 feet of vertical descent is adequate for a no wind launch, but this does not account for drag losses or rolling friction, so don’t depend on it. (This distance “18 feet” is derived just by dropping a mass and asking how far it would have to free fall to reach 23 mph. or so). For moderate winds, the “Rule of 18” seems to provide a rough guideline: “To get flying speed, the vertical descent in feet plus the headwind in miles per hour will equal 18”. Don’t confuse the “vertical descent” with the rolling distance, which will be a lot longer, of course. In practice, you’ll use extra rolling distance anyway, just to get some extra margin of airspeed. Nobody will want to take off as short as I have described unless they have to hop over a snake or something. 12. “…we only have a
