Glenn Leaver explains the importance of patenting the Descent-Vane-System.........
While the Descent-Vanes primary function is to arrest an unpowered descent, in forward flight its' function is that of an ordinary wing. However, historically, only a handfull of wings have been identified as having the necessary slow & stable vertical descent characteristics. These include the 1896 Montgomery Glider (Left, top) and the 1933 Pou du Ciel, (left, middle) both of which were tandem-winged. Besides its descent-arresting ability, the tandem planform provides greater stability and eliminates the yaw-induced "bobble" that can occur when torque-imbalances occur in the flying platforms' rotor. This "bobble" can be seen in this video (bottom left) of a single-descent-vaned test model. At about 1/3rd into the flight the models' tail momentarily interrupts the radio control signal, cutting-off the motor, but the model quickly regains its equilibrium.
BELOW: Pilots and non-pilot GI's learning to fly. A standing position was found to be more responsive, and a larger (8-foot-diameter) disk was more stable than the 5-foot disk shown here. Kinesthetics are similar to walking, except without friction with the ground to augment stopping/starting. Instead, one must estimate the lag/lead time for initiating or stopping motion, and this is what takes a few minutes practice. Mastery occured in as little as 5 minutes. For future test vehicles, the army included a Specification requiring it to be capable of being learned in less than 20 minutes.