For human being it takes approx 10-15 minutes (coached fly time) in wind tunnel until one can do basic movements there. After 1-2 hours there usually is ability

For human being it takes approx 10-15 minutes (coached fly time) in wind tunnel until one can do basic movements there. After 1-2 hours there usually is ability to do back-flying and carving. So, to be able to "fly" in freefall, it takes just about exposure to the element. Still, fascinating article and subject.