heh.. 99% of all aviation was "Off the Shelf" back then. Between finding good material combinations to the lack of materials over all from Depression to Wars to build with. I am thinking I would not be trusting my life to short wing spans let alone a "Pancake" that acts more like a parachute according to the narration..5 to 10 mph landing speeds.. He did not however say if that was horizontally or vertically.