The following items were extracted from some of the material we have available in the TWITT library.  They are only a small portion from each of the articles provided by our members over the years.  Click here for a complete bibliography of this material.
Kasperwing 1-80
   Single-seat, single-engine, high-wing monoplane with hybrid control.  Wing has swept back leading and trailing edges, and constant chord; no tail.  Pitch control by weight-shift; yaw/roll control by tip rudders; control inputs through tiller for yaw.  Wing braced from above by kingpost and cables, from below by cables; wing profile by W. Kasper; single-surface. 
    Undercarriage has three wheels in tricycle formation; no suspension on any wheels.  Push-right to-left nosewheel steering independent from yaw control.  No brakes.  Aluminium-tube framework with optional pod.  Engine mounted below wing driving pusher propeller.  Dacron used for covering wing and underside of mid-chord spar. 
    The Kasperwing 1-80 was designed by W. Kasper in collaboration with Steve Grossruck and the prototype constructed in 1976.  The Kasper effect allows the 1-80 to make vertical approach to landing while remaining stable in all three axes during a descent at 160ft/min. with a 154 lb. pilot.  It has a twin spar wing, each wing having six ribs folded into a flattened 'S' shape to give a stable profile.  The Kasper can be summarized as twin rudders carried on tripod struts at the extremity of each wing in such a way that the rudders are also used as vortex generators and as air brakes. 
    Powered by Zenoah G25B, 25 hp. engine with a max cruise speed of 45 mph.  Length 10', span 35', chord 5.6', height 11' and total wing area of 180 sq. ft. 

Source:  Cascade Ultralites 1983 promotional brochure.

Aircraft Wing With Vortex Generation - 
United States Patent # 3,831,885

    This is Figure 1 from the above patent.  It is a perspective view of the aircraft at rest, with all the directional control airfoils and vortex generating and control airfoils in their neutral positions.
    ABSTRACT:  Tailless airplanes, such as declared in U.S. Patent No. 3,438,597 as a stall occurs or is about to occur, may be flown at very high angles of attack to generate favorable spanwise vortex flows which augment the swept wing profiles creating resultant wing profiles having better lift characteristics, i.e., the vortexes created are lift generating.  However, the aircraft is then uncomfortable to be in during such flights at very high angles of attack.  Therefore, to achieve the benefits of this lift generating vortex flow, without maneuvering such aircraft into a very high angle of attack, the swept wing is equipped with airfoil structures and accessories which are extended beyond the cruising speed contour of the swept wing at lower speeds to create spanwise vortex air flows which selectably enlarge the effective overall airfoil contours as sensed by the passing major air flows.  Sustaining aerodynamic lift forces are thereby created at angles of attack well beyond the stall angles of the cruising airfoil contour and, by timely use of such airfoil structures, the vortex air flows are created soon enough for lift generating, so stable flight conditions may be created without so extensively altering the pitch of the landing and/or slow flying tailless aircraft.

by Witold A. Kasper

    The wingtip rudders are the second roll control system which also have the dual function of yaw control.  In order to balance out the aerodynamic force on the deflected rudder, an aerodynamic balance forward of the hinge line is provided. (Fig. III-8)
    This aerodynamic balance moves over the wingtip when the rudder is deflected, acting as a spoiler on the wingtip and also adding to the drag.  The spoiler action decreases the lift on the wing.  Consequently the lift differential on the wing produces a rolling moment in the direction of the actuated rudder.  Additionally, because the endplates and rudders are inclined outboard, when the rudder is actuated, its inclination produces an additional downward force helping the roll.  Actually, the turn can be made with the rudder alone, without the need of aileron to "coordinate" it.  The figure below shows this concept from a top view.

    Kasper wrote:  "The shape of the wing has to be rectangular, not tapered.  The reason is that pitch control is affected by changing the spanwise lift distribution.  We must have lift at that part of the wing where the elevators are located.  The wingtip stabilizers help to obtain an ellipitical lift distribution.  When the elevators are moved up or down, this ellipitcal lift distribution changes to a more or less triangular one, causing a considerable shift of the center of pressure inboard or outboard and, due to sweepback, forward or rearward." 
    The figures at the left show, from top to bottom, normal horizontal flight, nose down flight, nose up flight and, rolling flight.  Kasper used the bird symbology, since he felt his aircraft were as close as any yet designed to simulate controlled flight like the birds.  He had extensively studied birds and insects throughout his life trying to find why they flew so well and man's inventions did not. 
   Again, Kasper wrote:  "The concepts that I have presented are facts, not theories only, proven by flying and testing Flying Wings of my own design.  My research also serves to explain why earlier designs of flying wings and tailless airplanes by others, both in this country and Europe, were failures and based on wrong assumptions.  I hope my fellow airplane and glider designers are open-minded enough to accept what I have offered as a contribution to their search for a safer and better air vehicle.  Let us fly like a BIRD!"

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