A glider is an airplane with no engine. Gliders must be towed (or launched) into the air and stay aloft until gravity takes over and they, hopefully, land back on earth. They stay up by lift generated through air pressure. Air passing over the top of the wing must travel faster than the air at the bottom of the wing. This creates highe air pressure under the wing, creating lift. The same principle applies to hang-gliders where the passenger(s) are suspended under one giant wing.
 
 
 

The Brainy Bunch David, Michael & captain Chess hang-gliding champ David Rainer, insert	In A Spin clockwise: Trevor, captain Rob aircraft designer Dr Billy Brooks & Shaun
A lightweight glider? From 2 monstrous airplane wings?	See, the air flowing over the top has to catch up the air underneath the wing which provides lift
I think you'll be needing that at the end of the day	Our judge is 80 year old fly-girl Anne Welch. I wonder if she knows J.Lo?
The look simply (pop) riveting	Hey! That's Robert's ride home!
Robert & Cathy discuss the team's respective designs	Robert inspects the yellow's handywork.