Hang Glider Design and Performance

Abstract

Hang gliding represents a less known but sizable segment of the sport aviation community. This sport experienced a rebirth in popularity during the 1970s with the advent of new, simple wings developed by pioneers like John Dickensen based on a wing concept developed through NASA engineer Francis Rogallo’s work. This paper will summarize hang glider technical development from the late 1800s to the current generation of designs. Hang glider structural and aerodynamic design features differ significantly from those of traditional aircraft design. This paper discusses these differences, including sail flexibility, structural design philosophy, and wing twist. Current hang glider design falls into two primary genres: Flexible and rigid wings. The flex-wings are the most popular and are direct descendents of the wings developed by Francis Rogallo and John Dickensen. Since the 1970s they have evolved into much safer, higher performing wings. They now have very pleasing handling qualities, and are capable of multiple-hour flights over great distances. The rigid wings have structural design features more similar to traditional aircraft, offer improved glider performance, and utilize composite materials extensively in their structure, all at increased cost and weight. The flex-wing product line of the Wills Wing company was evaluated in depth with a detailed build-up of drag and glide performance estimates shown.