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  • hovering gyrocopters

    Let the eye rolling begin...but here goes. I'm new to rotorcraft and I'm sure this question has been asked since the dawn of gyrocopters, but if the pre-rotator were powerful enough could it enter a controlled hover? Or are the blades pitched wrong for that? I know of one gyro company that is making VTOL gyrocopters (https://skyworks-global.com/), so I believe it's possible to have a VTOL gyro. Just curious what everyone out there thinks.
    Thanks!

  • #2
    Hover: remain in one place in the air.

    An autogyro (from Greek αὐτός and γύρος, "self-turning"), also known as a gyroplane or gyrocopter, is a type of rotorcraft that uses an unpowered rotor in free autorotation to develop lift. Forward thrust is provided independently, typically by an engine-driven propeller. While similar to a helicopter rotor in appearance, the autogyro's rotor must have air flowing across the rotor disc to generate rotation, and the air flows upwards through the rotor disc rather than down.

    If it has a powered rotor it is a helicopter, not a gyroplane and you need a helicopter license to fly it unless it is an ultralight.

    Sec. 103.1 Applicability.

    This part prescribes rules governing the operation of ultralight vehicles
    in the United States. For the purposes of this part, an ultralight vehicle
    is a vehicle that:
    (a) Is used or intended to be used for manned operation in the air by a
    single occupant;
    (b) Is used or intended to be used for recreation or sport purposes only;
    (c) Does not have any U.S. or foreign airworthiness certificate; and
    (d) If unpowered, weighs less than 155 pounds; or
    (e) If powered:
    (1) Weighs less than 254 pounds empty weight, excluding floats and safety
    devices which are intended for deployment in a potentially catastrophic
    situation;
    (2) Has a fuel capacity not exceeding 5 U.S. gallons;
    (3) Is not capable of more than 55 knots calibrated airspeed at full
    power in level flight; and
    (4) Has a power-off stall speed which does not exceed 24 knots calibrated
    airspeed.

    If it has a powered rotor it will likely need an anti-torque rotor unless it is jet tip or coaxial.

    To fly well it will need an inflight adjustable pitch rotor.

    A gyroplane with enough power will fly in one spot over the ground at somewhere around twenty miles per hour. Some people call this hovering.

    Some gyroplanes can do a jump takeoff (vertical takeoff) but will not hover.

    I wish you all the best on your aviation adventure.
    Regards, Vance Breese Gyroplane CFI http://www.breeseaircraft.com/

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    • #3
      You seem to be confusing vertical take-off with hovering. They are not at all the same thing.

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      • #4
        Thank you for the responses. To be more specific, I am interested in the tip jet approach. The reason for the question was to get an idea whether I would need to convert a helicopter with all it's complicated blade manipulation machinery and unnecessary tail rotor, or if I could just start with a gyro and modify the tail feathers. The Dragonfly DF1 was a successful implementation although I'm not interested in H2O2. Would a tip rotor helicopter need to have all the complicated blade manipulation machinery and controls of a helicopter? The Dragonfly seemed to just have a throttle, rudder and teetering "joystick" to tilt the rotating blades the desired direction (somewhat like a gyro).

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        • #5
          In my opinion tip jet helicopters fly better with collective pitch.

          They will fly with slower (less) control with a fixed pitch rotor system using the throttle to control rotor rpm.

          There have been several successful tip jet helicopters.

          In my opinion the method of tilting the rotor disk in a helicopter is not particularly complex.

          Both helicopters and gyroplanes use cyclic control to tilt the rotor disk aerodynamically.

          Because there is no drive shaft in a tip jet helicopter a tilting head will work although it may not be the best choice.

          There is a lot of information out there on what has been successful and what has not when it comes to tip jet helicopters.

          Stanley Hiller experimented with ram jet tip jet helicopters.
          https://en.wikipedia.org/wiki/Hiller_YH-32_Hornet

          Sud-Quest produced a cold tip jet helicopter in France.
          https://en.wikipedia.org/wiki/Sud-Ouest_Djinn
          Regards, Vance Breese Gyroplane CFI http://www.breeseaircraft.com/

          Comment


          • #6
            I've never seen it in person, but from online photos it looks to me that the DR-1 had a collective control (see photo) and it's hard to imagine a practical helicopter without it. Relying on throttle/rpm variation for collective effect would be a big challenge, and make autorotation after power failure problematic at best (even tip jets can become fuel starved or otherwise quit producing thrust, and one would want to survive). You won't have any provision for varying collective pitch if you use a typical gyroplane rotor. The only gyros I know of with any sort of controllable collective pitch are the A&S 18A and the McCulloch J-2, both of which use a fully articulated rotor system. Take a look at the Hiller Hornet if you want an historical perspective with simplest possible construction.

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            • #7
              Thanks guys, very good information! I came across a gentleman who is in talks with a manufacturer to bring his tip jet ultralight helicopter to production. Who knows if it ever will (if I had a nickel for every...), but his design is very intriguing. He is using the helicopter blade manipulation mechanisms to control the aircraft, even with the tip jets. I was just curious if there was a simpler way to do it. Learning how to fly a helicopter is very difficult and more people would be interested if there wasn't such a steep learning curve.

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              • #8
                Originally posted by barracj View Post
                Learning how to fly a helicopter is very difficult and more people would be interested if there wasn't such a steep learning curve.
                I would suggest that the COST of helicopter flying (both up-front and hourly) is a greater impediment to most people than the actual challenge of learning to fly one.

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                • #9
                  One of the applications I was thinking about for tip-propelled rotorcraft, or hovering VTOL gyrocraft if that's even possible, is for the new wave of passenger commuter aircraft (Uber, etc.). Skyworks Global shows their version of a VTOL gyro used for that purpose. The one great advantage I see for such a craft over the new wave of quadcopter-type craft is the ability to auto-rotate in the event of a motor/battery failure. It's true that many of the designs currently on the board have many motors spread across the structure and boast the ability to still land safely if one or two motors fail, but they still need redundant batteries as well, which is all extra weight. A VTOL gyro/tip jet commutercraft (helicopters are just too complex to make computer-controlled) can still auto-rotate near vertically in the event of a motor/tip jet failure. Seems like a no-brainer. Addition: apparently a hover-capable gyro is called a gyrodyne. A Heliplane was a DARPA program for a gyrodyne using tip-jet propulsion for VTOL and a wing/jet engines for forward flight.
                  Last edited by barracj; 09-14-2018, 08:15 AM.

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                  • #10
                    According to the FAA:

                    Rotorcraft means a heavier-than-air aircraft that depends principally for its support in flight on the lift generated by one or more rotors.

                    Gyrodyne means a rotorcraft whose rotors are normally engine-driven for takeoff, hovering, and landing, and for forward flight through part of its speed range, and whose means of propulsion, consisting usually of conventional propellers, is independent of the rotor system.

                    Gyroplane means a rotorcraft whose rotors are not engine-driven, except for initial starting, but are made to rotate by action of the air when the rotorcraft is moving; and whose means of propulsion, consisting usually of conventional propellers, is independent of the rotor system.

                    Helicopter means a rotorcraft that, for its horizontal motion, depends principally on its engine-driven rotors.

                    In my opinion using the term gyroplane incorrectly leads to misunderstanding. As soon as you power the rotor in flight it no longer fits the FAA definition of a gyroplane.

                    There have been gyroplanes that can do vertical takeoffs and landings; they just can't hover because the rotor is unpowered.

                    In my experience helicopters are not particularly difficult to learn to fly.

                    With no aviation experience I was ready to solo a Robinson 44 in a week and 21 hours of dual instruction. For me learning to hover was probably the most difficult task.

                    I did not have a valid medical at the time so I never did solo a helicopter.

                    It took me longer to solo a gyroplane despite or perhaps because of my helicopter experience.

                    There are autopilots for helicopters; in other words there are already computer controlled helicopters.

                    Remote controlled model helicopters have fairly simple control systems and are quite maneuverable.

                    In my opinion the ability to land safely if the engine stops making power is important for any aircraft with people on board.

                    I feel you understanding would expand if you saw gyroplanes close up and/or took a flight in one. The Ken Brock Freedom Fly in at El Mirage Dry Lake is September 28-30 and is very near to you. I will be there with my gyroplane.
                    Last edited by Vance; 09-14-2018, 10:07 AM.
                    Regards, Vance Breese Gyroplane CFI http://www.breeseaircraft.com/

                    Comment


                    • #11
                      barracj, i think what you are looking for is the Fairey Rotodyne.

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