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Thread: VTOL Whatsit

  1. #1
    Registered User Tiger Tim's Avatar
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    VTOL Whatsit

    Alright, I'm stumped. What's this?

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    Registered User D Hillberg's Avatar
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    Re: VTOL Whatsit

    Was at the Camarillo air show powered by a V 8, It needs a turbo-shaft way under powered as for the name... Beat's me - I forgot. but It's a local guy...

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    Registered User Victor Bravo's Avatar
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    Re: VTOL Whatsit

    Bullwinkle: "Hey Rocky, wanna see me pull a rabbit out of my hat?"
    Rocky: "Again....?"

    Roger Daltrey: "Then I'll get on my knees and pray... We don't get fooled again"

    Stephen Pearcy (Ratt, 90's rock band): "Round and Round.... What goes around comes around"

    Alice Cooper: "Welcome to my nightmare"

    Mr. Quint (Robert Shaw): "Farewell and ado to ye fine Spanish ladies..."

    Riff Raff (Richard O'Brien): "Frank N Further it's all over - your mission is a failure, your lifestyle too extreme"

    Dr. Strangelove (Peter Sellers): "The whole purpose of the Doomsday Machine is lost if you keep it a secret - why didn't you tell the world?"

    Dr. Strangelove (end theme): "We'll meet again, don't know where / don't know when, but I know we'll meet again some sunny day"
    "Everything in this book may be wrong."
    Richard Bach, Illusions


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    Moderator Topaz's Avatar
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    Re: VTOL Whatsit

    Quote Originally Posted by Tiger Tim View Post
    Alright, I'm stumped. What's this?
    Based on the numerous attempts in the past, chances are that it's either...

    A) An airplane you'll never see again, which will simply fade away after it turns out to have some grossly inadequate flight characteristic.

    B) The beginning of another sink-hole for investor money which will live on for decades, always "very close to an announcement of full production," while occasional YouTube videos appear of it staggering into tethered vertical flight a few inches above the ground. These videos will usually surface a few weeks before the next round of investment funding is sought.

    More seriously, I genuinely hope that I'm wrong and that this succeeds. People have been dreaming of a true VTOL "airplane like" homebuilt for decades. But it's extremely difficult to do, as witnessed by the number of government and industry attempts at VTOL flight that have failed miserably.

    Those look like fixed-pitch props, and Hillberg is saying this is powered by a V-8. I'd say, therefore, that the chances of this one working out probably approach zero.
    "If you have built castles in the air, your work need not be lost; that is where they should be. Now put the foundations under them." - Henry David Thoreau

    Design Project: Conceptual Design of an "Inexpensive" Single-Seat Motorglider
    Discussion Thread for the Project: Discussion: Conceptual Design of an "Inexpensive" Single-Seat Motorglider

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    Registered User bmcj's Avatar
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    Re: VTOL Whatsit

    How is the front fan powered? Did they manage to squeeze a long driveshaft in there somewhere?

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    Registered User D Hillberg's Avatar
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    Re: VTOL Whatsit

    Quote Originally Posted by bmcj View Post
    How is the front fan powered? Did they manage to squeeze a long driveshaft in there somewhere?
    hydraulic moter

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    Moderator Topaz's Avatar
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    Re: VTOL Whatsit

    Don, do you know if it's even tried to hover yet? Has it flown in HTOL mode, either?
    "If you have built castles in the air, your work need not be lost; that is where they should be. Now put the foundations under them." - Henry David Thoreau

    Design Project: Conceptual Design of an "Inexpensive" Single-Seat Motorglider
    Discussion Thread for the Project: Discussion: Conceptual Design of an "Inexpensive" Single-Seat Motorglider

  10. #8
    Registered User D Hillberg's Avatar
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    Re: VTOL Whatsit

    Quote Originally Posted by Topaz View Post
    Don, do you know if it's even tried to hover yet? Has it flown in HTOL mode, either?
    All I know is it was run up but not flown yet. If you look closely it's my neighbor beyond the back of my toys
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

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    Moderator Topaz's Avatar
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    Re: VTOL Whatsit

    Thanks, Don.
    "If you have built castles in the air, your work need not be lost; that is where they should be. Now put the foundations under them." - Henry David Thoreau

    Design Project: Conceptual Design of an "Inexpensive" Single-Seat Motorglider
    Discussion Thread for the Project: Discussion: Conceptual Design of an "Inexpensive" Single-Seat Motorglider

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    Re: VTOL Whatsit

    I think for an aircraft like this to be reasonable, you have to invent the Mr. Fusion first. This is probably why the DeLorean failed too.

    I wonder how many gallons per second on the vehicle we see above?

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    Moderator Topaz's Avatar
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    Re: VTOL Whatsit

    I'm less concerned about absolute thrust. Don's information is that it has a V-8 of some kind and while the power to weight of any V-8 I know of is unlikely to be able to lift this out of ground effect (assuming it can become airborne at all), I can only say "unlikely" and not be definitive about that at all.

    The bigger concern for me is the seeming complete lack of 3-axis controls in hover and transition. While it may be that there are control "vanes" in each of the ducts, those aren't going to be very effective on such a large and heavy aircraft, as has been demonstrated again, and again, and again in attempts at VTOL homebuilts. Better would be to have variable-pitch props in each duct so that thrust can be varied for roll and pitch, and then maybe use vanes in the nose for yaw. That would be a far more powerful control system. But even though there might be two props per duct (it's hard to tell, but I think I see one blade if a second "bottom" prop in the near-side rear duct), they appear to be fixed-pitch units which don't allow variable thrust. Barring some hellishly complex variable-speed transmission for each duct, I don't see any way to vary the thrust of each prop for good-authority control in roll and pitch.

    This is the single most overlooked aspect of most homebuilt VTOL attempts: The control power requirements during transition from vertical to horizontal flight (and vice versa) are much greater than that for pure horizontal or even vertical flight, and have been the undoing of many (both government and private) attempts at a VTOL design. Most private designers seem to concentrate on getting enough thrust to lift off vertically, and then throw a few vanes in the lifting-device flow to control the airplane. Time and time again, this has been shown to be inadequate in most design cases, and especially ones with lifting ducted fans like this. Successful VTOL aircraft have either had separate Reaction Control System nozzles with bleed air from the jet engines providing the thrust (Harrier and F-35, for example), or either rely upon differential thrust for control during hover and transition (X-19, X-22, etc.). Most of the failures have done neither, and have simply tried to use vanes in the lift thrust flow. Sometimes that's good enough for hovering flight, but is usually overwhelmed during transition, with the flight often ending very, very badly.

    Unless I'm missing something in the photo, this looks to be one of the latter, at best. I'm just speculating, of course. Perhaps the designer has provision for a solid vertical/transition control system and I just can't see it. I'd like to be proven wrong.
    "If you have built castles in the air, your work need not be lost; that is where they should be. Now put the foundations under them." - Henry David Thoreau

    Design Project: Conceptual Design of an "Inexpensive" Single-Seat Motorglider
    Discussion Thread for the Project: Discussion: Conceptual Design of an "Inexpensive" Single-Seat Motorglider

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    Registered User BBerson's Avatar
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    Re: VTOL Whatsit

    It looks like a non-flying mockup.
    Successful VTOL development starts with crude open frame test vehicles, not white painted sculptures such as this.

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    Registered User bmcj's Avatar
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    Re: VTOL Whatsit

    Quote Originally Posted by D Hillberg View Post
    hydraulic moter
    I wonder how much power that absorbs (wastes)?

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    Registered User Dan Thomas's Avatar
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    Re: VTOL Whatsit

    Quote Originally Posted by Topaz View Post

    Unless I'm missing something in the photo, this looks to be one of the latter, at best. I'm just speculating, of course. Perhaps the designer has provision for a solid vertical/transition control system and I just can't see it. I'd like to be proven wrong.
    As Don implies, it might have hydraulic motors driving the props. Control of fluid flow could vary the RPM independently. But heavy. Very heavy.

    This is instructive: https://www.youtube.com/watch?v=O5Gk...eature=related

    Helicopters have cyclic controls for some very good reasons. Drones use rotors spaced apart and some fancy computer stuff to stabilize and control the machine.

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    Moderator Topaz's Avatar
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    Re: VTOL Whatsit

    Quote Originally Posted by Dan Thomas View Post
    As Don implies, it might have hydraulic motors driving the props. Control of fluid flow could vary the RPM independently. But heavy. Very heavy.

    This is instructive: https://www.youtube.com/watch?v=O5Gk...eature=related

    Helicopters have cyclic controls for some very good reasons. Drones use rotors spaced apart and some fancy computer stuff to stabilize and control the machine.
    Heavy and not terribly responsive, I would think. Good video. Yep, vanes just don't cut it in almost every scenario.
    "If you have built castles in the air, your work need not be lost; that is where they should be. Now put the foundations under them." - Henry David Thoreau

    Design Project: Conceptual Design of an "Inexpensive" Single-Seat Motorglider
    Discussion Thread for the Project: Discussion: Conceptual Design of an "Inexpensive" Single-Seat Motorglider

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