OTHER: Helicopter - Inside - Interleaving - Simple Very-Light Rotorcraft

• A laterally symmetrical Interleaving configuration;
• To eliminate the need for constant yaw control.
• Incorporates Absolutely Rigid Rotors and a simplistic Advancing Blade Concept
• To provide a faster response to cyclic control inputs.
• To reduce the downwash on the fuselage during hover, the pitch on the advancing side (outside forward) will be approximately 3º greater than the pitch on the retreating side (over the fuselage).
• Targeted at the Very-Light Rotorcraft catigory.
• Gross Weight is 600 kg (1,320 lbs) or less.
• Two seats.
• Should have flight characteristics similar to an airplane, with the added feature of vertical takeoff, landing and hover.

• Probably a greater vibration on the fuselage due to downwash during hover, however the six blades and smaller blade radius will place any vibration at a frequency of +/- 50 Hz., which is considerably removed from the objectionable 15 hz. In addition, this higher frequency (due to more blades) will result in lower amplitude. Also, the ABC rotor will reduce the downwash from the retreating blades during forward flight. Whether the vibration is acceptable or objectionable is anyone's guess.
• The opposing gyroscopic processional forces of the two rotors during maneuvers will necessitate that the frame between the two rotors be stronger than if the rotors had minimal rigidity (such as teetering rotors w/ 90º phase angle).
• Portability will probably require that the blades and the tail be built as being removable.
• Is there the possibility that during a possible stall, one rotor might stall before the other?

• Early 1-seat interleaving helicopter. OTHER: Helicopter - Outside - Interleaved - Landgraf ~ H-4
• General: OTHER: Aerodynamic - Rotor Disk - Dual Configuration - Interleaving
• OTHER: Helicopter - Inside - Interleaving - Advanced Very-Light Rotorcraft
• Electric Very Light Interleaving
• A toy for playing with or testing with; OTHER: Helicopter - Inside - Interleaving - Rubber-Band Powered Model

• Disk loading:
• The overlapping area will produce a disk loading that will be just about twice that of the non-overlapping area. This is because twice as many blades are passing through the overlapping area. An advantage of this in forward flight is that the high thrust from the tips of the retreating blades on one rotor are operating in the low thrust root area of the other rotor. A disadvantage is that the fuselage is in this area, however ~.
• The craft's rotors high rigidity, therefore lateral symmetry of lift between the retreating side and the advancing side of the rotors is not necessary. This means that the thrust in the overlapping area can be reduced and the thrust on the outside halves of the disks can be increased.
• During hover the downwash on the fuselage and spars will be significantly reduced. In addition the fact that there are twice as many blades passing over the fuselage will double the frequency (For a Very-Light helicopter the frequency will be roughly 500 RRPM x 6 / 60 seconds = 50 hz, which is quite removed from the worst at 15 hz). The greater thrust on the advancing blades (outside forward) = greater drag on the advancing blades = slight longitudinal reverse thrust.
• During cruse, the same will apply plus these blades will now be retreating and moving the thrust further out toward the blade tips. In addition the ABC concept will further reduce the downwash on the fuselage

• Rotor Governor
• Independent Root & Tip Control (incorporating Reverse Velocity Utilization)
• Large Chord and Low Tip Speed
• Pusher Propeller

• OTHER: Helicopter - Inside - Interleaving - Morphing

Modified Configuration: Added December 27, 2006

• Both rotors have horizontal planes. If their precone was increased to 5 or 6-degrees the rotors could have their stagger distance reduced. This would make the craft very much like an intermeshing configuration without the disadvantages of angled rotors. As an alternative to the three crown and pinion transmission(s) consider this OTHER: Helicopter - Inside - Intermeshing - Belt Driven
• If the blades were given a larger chord and the rotor a slower RPM then the natural coning angle will be closer to the above increased coning angle. This will reduce the resistance of the pitch bearing, but this smaller aspect ratio will probable in crease the percentage of the tip loss.

• OTHER: Flight Dynamics - Rotor Hub - Constant Velocity Rotor w/ Hub Spring

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