Nice try but your gliding theories are wrong.
Gliding starts when there is enough AIR speed. Combine that with angle of attack to produce required lift. Sheeting in means you are increasing the angle of attack to have more lift from airfoil.
When airborne there is no wind window. There is head wind and tail wind depending trajectory you are flying. Wind is visible to flyer as ground speed. Then there is wind upward component caused by the shape of ground. Wind turned upwards can go really high as glider planes prove that (and 'wave' clouds).
Then there is sink rate, wing loading, g force... Don't kill yourself.
On the movie Speed3 kicks some ...