Hang-gliding instructor Ron Freeman stands tentatively at the edge of a pier on England’s south coast, assessing the wind speed. It’s warm with a slight breeze, the perfect conditions for the day’s International Birdman rally. His mind, body, and glider (the Geordie Flyer) are ready. Now, all that stands between Freeman and the £10,000 prize is 100 meters (roughly 330 feet) of the English Channel. The International Birdman has been a stalwart of a smattering of British seaside summers since the early 1970s. Competitors raising money for charity leap off…