For those who don't know of Mark's connection to the beginnings of modern hang gliding along with his brother Jack and the Hang Loose glider, here is a link to a video "spur-of-the-moment" interview I made of Mark at our 45th Lilienthal anniversary meet, at Dockweiler last year.
https://vimeo.com/167829006Also, in the historical account of that 1st, May 23, 1971, hang gliding meet it was Mark who kept the FAA off our backs. That may have had a profound effect on the future of the sport of modern hang gliding.
We could have been shut down before we even got started.
Thanks Mark. May the celestial thermals keep you soaring.Frank