US Patent 6,648,272 B1
The KOTHMANN is an advanced vehicle intended to provide Airship operation for a wide range of applications. It is easy to operate, easy to maintain, and easy to build. The intended operational capabilities will satisfy low cost, low altitude flight with simple controls and a high degree of maneuverability and safety. The Kothmann can repetitively land anywhere and off load without the need for ground crew or mooring facility.
Today there are less than 30 operational airships in the entire world. There should be thousands.
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The KOTHMANN MULTI-USE AIRSHIP
Traditional Airships cost millions of dollars, are difficult to manufacture, difficult to fly, extremely expensive to maintain, and require large ground installations and crews. The Kothmann Airship is a lighter-than-air (LTA) craft, which is capable of performing repetitive landings and take-offs without the need for service, replenishment, ground crew or mooring structure of any kind, allowing the craft to deliver many consecutive payloads. The Airship can remain on station for very long periods either manned or unmanned. The aircraft is easy to assemble, out performs traditional airships, costs about 20% of a comparable size traditional airship, and does not require complicated systems for flight controls. Vertical lift and decent is provided by separate and redundant systems that when used in concert provide maximum control and payload utilization. Horizontal propulsion is provided by 2 fixed motor driven ducted fans located interior to the aircraft. Control surfaces within the propulsion duct provide horizontal, lift and decent control. The Construction is simple using two separate envelopes. The helium containing Inner envelope uses proven Thin Film Technology and reinforced seaming methods. Current technology also allows the construction of fabric covered rigid tension structures that cover very large areas or air supported structures such as exhibit domes.
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This technology is incorporated in the outer fabric envelope of the airship and will contain the inner thin film gasbag in a fixed volume. The double component envelope will cheaply contain the pressure required to attain variable displacement and controlled vertical flight.
Section: Bow to Stern The Kothmann’s simplified construction becomes “rigid by pressure as well as by its own weight. All forces are transferred to the Compression Ring that gives the airship its distinctive lenticular shape. The greater the force on the fabric, the greater the force on the compression ring, however, the interior lifting gasbag shall not experience surface stress (tension) along any seam or surface. The shape becomes rigid-by-gravity when the air ship is filled. However, the airship does not need higher internal pressure to become ridged and will operate at less than optimal lifting gas volume. When the aircraft is inflated with the lifting gas, the structural fabric (and/or) load tapes will evenly transfer both, the lifting gas forces as well as the dead load and payload of the aircraft to the compression ring in a similar manner as spokes on a bicycle wheel. The compression ring not only acts in structural compression, it is also the compressed gas receiver, storing over 1100 cubic feet of lifting gas. Lifting gas can be stored in the Compression ring by a compressor located on the equipment deck above the crew compartment. The aircraft’s primary vertical flight control system is provided by inflatable air bag positioned between the lifting gas bag and the deck in a sandwich type manner. Secondary vertical flight control (optional) is provided by a lifting-gas (helium) management
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and conservation system. By compressing the lifting gas into the compression ring together with simultaneously adding additional pressure in the diaphragm air bag, allows vertical flight control over a wide range of temperatures and altitudes and also compensates for the cargo and passengers Pressures and temperature variances will not affect the capability of the Kothmann airship, which will maintain level altitude flight throughout the daily temperature cycles, via the lifting gas management systems. The Kothmann is also able to “stick”, like a suction cup, to any relatively smooth paved surface. Immediate off loading of passengers and cargo is facilitated by “sticking” the airship to any paved surface similar to the way a suction cup or child’s play dart will stick to smooth surfaces. The bottom ring attached around the crew compartment is designed so that a small amount of space exists between the ground and the deck. When the aircraft lightly touches a paved surface, the pilot engages the electric suction fan which will evacuate the small volume of air that is captured between the ground and the crew compartment floor allowing the suction fan to create negative pressure. This immediate suction will create a hold down pressure of over 8,000 pounds. The suction fan will be powered by either the primary electrical system or the auxiliary generator. The Turbine suction fan is a common industrial off-the-shelf item. The pendulum nature of the loads makes the airship very easy to control during flight and the landing process. The Kothmann can go up or down like an elevator. The pendulum loads will reduce or eliminate unwanted pitch and yaw which is common to traditional airships. The center of buoyancy is static, unlike traditional airships and is located directly above the center of gravity. Propulsion is provided by any conventional motor-driven propeller located in the rigid propulsion duct. This rigid framed tube also acts as a structural box girder in forming a key structural element of the aircraft. Optimum horsepower is approximately 800 HP. The fan duct is lined with perforated aluminum which is acoustically tuned to reduce prop and engine noise. The fan duct will act like a large muffler and the Kothmann will be virtually silent under full power. The location of the equipment and engines allow maintenance and repair while in flight. Controlled flight for the aircraft is achieved by locating conventional control surfaces at the outlet of the propulsion duct. The rudder will
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rotate the craft in either horizontal direction for 360 degrees, and can reverse the craft’s direction in flight. The vertical flight control surface is the rear horizontal lifting-plane(s). The outer structural envelope or hull determines the maximum expansion limits of the thin film lifting-gas bag and also the shape of the aircraft, and therefore, the volume will not fluctuate due to pressure. The airship is capable of controlled variable lift and decent using an inflatable diaphragm that will modulate the pressure in the lifting gasbag by selectively forcing air into the diaphragm through 2 high pressure electric turbine blowers; the diaphragm is not necessarily located within the gas bag. Thrust from the engines is not required for charging the diaphragm with ambient air. The perimeter of the equipment deck is defined by a radial truss forming the deck enclosure. Angular structural members are attached to the radial truss. The airships equipment including generator, blower fans, and compressor are mounted in the equipment deck, located above the crew compartment. Plan View Equipment Deck 16’ dia
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Top Plan View of Diaphragm Deck 50’ dia
The outer perimeter of the “diaphragm” deck is formed by a tension ring, to which the outer hull structural fabric is connected. This deck supports the downward forces created by the pressure variance within the lifting gas envelope and also serves to structurally stiffen the airframe. Angular structural members radiate outward from the radial truss, which act in tension when the craft is lighter than air. .
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The Airship is simple to assemble in the field from a minimum of 6 pre-manufactured assemblies. The rigid frame assembly also includes the propulsion unit and all other equipment such as the generator, fuel tanks, pumps, fans and controls. The airship can be field assembled and deployed by a small crew in approximately 40 man hours, or it can be disassembled and transported to remote locations. The airship is aerodynamically stable over a wide range of atmospheric conditions, altitude, and speed. The Airship can lift and deploy up to 5,000 pounds without the need for cables or rigging, but by means of the pneumatic suction “Hold-Down” system. The airship’s shape together with the vented fabric hull will allow the safe and reasonable use of Hydrogen as a lifting gas. The shape also offers a much larger operating platform than traditional airship design. The lenticular shape can be of great value when incorporating on-board antenna arrays. The airship amalgamation can be modified in simple fashion to allow many different mission capabilities. Moreover, the airship can offer freight service to remote regions of the world for less cost than other air transportation. The minimum size for the aircraft will be approximately 90’-0” in overall diameter, optimal size is 120’ diameter. The 200’ diameter offers a payload capacity of 15 ton. Persons with minimal training and basic navigation skills can safely operate the Kothmann. All components of the airship are current off the shelf technology. The Cost of the prototype is $450,000.00 compared to 2 or 3 million for a traditional airship design.
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Stacking for Heavy Lift
The Heavy Lift requirement is accomplished by linking as many airships as necessary. Each airship contributes its maximum lift potential. The 120 foot version will contribute in approximately of 9,000 pounds per airship. Larger Airship amalgamations are feasible. The rigid frame and mechanical portion of the airship can be interchanged with larger lifting shapes.
The Lower airship does not experience any more stress on the frame than the top airship. The cumulative lifting force is transferred to the center cable and each airship is simply adding a portion of the lift. Forward motion and speed is multiplied by the power of each airship that is attached in the chain. Linking an Airship “Train” is a relatively simple. A hatch in the crew compartment floor allows direct physical and visual contact with the payload or another airship. The airships need not detach from each other in order to
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deliver a payload and can simply return to the loading zone, still assembled, for anther load. No additional ballast such as water is needed for the Heavy Lift Train to accomplish the mission. Each airship can “pressure up” to decrease atmospheric displacement so that when the payload touches earth, detachment is immediate and the assembly may proceed to attach another load or disperse to another loading zone.
Figure 2
The portion of the cable extending through the body of the airship is independent of the winch cable that extends through the crew compartment. Even though a Train cable may have 50,000 pounds of cumulative load.
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Descriptions by Number Symbol 1. 2. 3. 4. 5. 6. 7. 8. 9. Helium Chamber Lifting Gas Bag Sandwich (Diaphragm) Deck Rudder Assembly Gondola Triangular rigid frame Inflatable Air Bag Fixed Propulsion Engine Compression Ring Electric Motor Wench
10. Connection Plate 11. Radius Truss 12. Stern Plane control surface 13. Bow Plane control surface 14. Semi-rigid foam bottom ring 15. High Pressure Blower Motor 16. Outer Layer Fabric Envelope Material 17. Equipment and Maintenance Deck 18. Tension Ring 19. Auxiliary Generator 20. Gas Compressor 21. Load Tape 22. Horizontal Rigid Propulsion Duct 23. Suction Fan 24. Cable 25. Fuel Tank 26. Belt drive and clutch 27. Hatchway 28. Webbing 29. Aluminum corrugated deck or skin 30. Structural Strut or Cable 31. Pressure Reducing Valve
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