The Fleep began as the Flex-Wing. The Flex-Wing had four-wheel landing gear, a smaller nose section behind which the pilot sat, and a single vertical tail/rudder, whereas the Fleep had tricycle landing gear, a larger nose section and a V tail/rudder. The wing was a fabric delta-shaped Rogallo wing with a fold-able frame; the wing was attached to a pod-like cockpit on a four-wheeled cargo platform. It was tested with two tail configurations — vertical fin and V-tail. The aircraft wing could be folded into a relatively small package for transport.