William H. Wolf designed the Sportwings Valkyrie as hang gliding mushroomed in popularity during the early 1970s. The Rogallo wing hang gliders that resembled huge, manned kites initially fueled this surge in public interest. A Rogallo was a fine choice if the pilot wished to fly in conditions for which it was designed, short flights in mild weather. When pilots began to use this glider for long distance flights, often flying through turbulent air, many found that the Rogallo performed poorly.
Bill Wolf believed he could design a better, safer hang glider by adopting certain layout and design features used on conventional aircraft. Wolf had taken to hang gliding while working as an aircraft flight instructor in Indiana. He first flew a Rogallo and found the kite-like glider adequate above the hills and the strong coastal updrafts prevalent in the West where the sport was most popular. Wolf found the Rogallo's performance completely unsuited to flying in the calmer air above the flat fields of Indiana. He decided to design and build a hang glider better suited to these conditions and the terrain. After studying texts on aerodynamics and aircraft construction, he came up with a design that was easy to build, required a light touch on the controls, and was stable and responsive in the air.
Wolf's Valkyrie was a tailless monoplane wing made of aluminum tubing covered with Dacron fabric. The wing's aspect ratio (ratio of wingspan to chord) was high and longitudinal stability might have suffered if Wolf had not suspended the pilot in a swing seat beneath the wing, to act like a pendulum that stabilized the wing nicely. He increased lateral stability by angling the wings up at seven degrees dihedral. Steel cable bracing held the airframe rigid. Wolf's approach to flight control was also novel. A pilot controlled her pitch by shifting her seat fore and aft. To turn, the pilot twisted grips on the control bar to deflect rudders mounted below each wingtip. When the pilot twisted both rudders simultaneously, they became dive brakes to slow and dive the glider. The Valkyrie was simple to build and easy to knock-down and transport atop an automobile, and it flew well in light winds above flat terrain.
Victor D. Powell, past President of the United States Hang Glider Association (USHGA), built this Valkyrie and then generously donated the aircraft to the National Air and Space Museum on March 16, 1978.
-- Smithsonian Air and Space Museum
https://airandspace.si.edu/collection-objects/sportwings-valkyrie
Indianapolis Star, April 6, 1983
