Very Interesting Aircraft Idea

The more parts you have the more that can go wrong. It's a cool design but I'm not so sure.

thats true... but I think the 'specialized' moving parts are localized to the rotor area.

whereas, something like the Puffin idea has moving parts all over, and counterrotating props as well, and to me is even more complicated.

cheers

Chris

The first thing I thought of was, "what happens when one of the rotors hits a bird, or get caught in a hail storm"? If you lose a rotor for any reason one side gets loaded and you lose lift and go into a roll. Of course this can be compensated for but you're still losing lift. I just see a lot of potential problems in the take offs and landings. Not to mention the maintenance cost to keep all those rotors and motors in great shape.

don't fly in hail or bird storms.

Further proof that government funding for the Osprey and AV8B Harrier was another over spending boondoggle. All the developers had to do was make a CGI and everyone would buy it.

Now that I've made my sarcastic remark, allow me to be specific in my concerns of this design approach. First, I see no provisions for a power source air inlet and a sufficient unused volume for its fuel. I really don't buy the idea that a completely self contained engine could reside behind the pilot compartment. The size of the rotors makes me greatly wonder if this could possibly be able to vertically lift itself but still fit inside an automobile parking space and carry the mass of one typical human. I see nothing that is supposed to be providing horizontal thrusting during the non-rotor part of the flight. The only candidate offered in the video for horizontal motion is the aft thrust of the mystery engine and glide path translation. With three stubby wings, this has a very low aspect ratio and will fall like a steerable rock. http://science.howstuffworks.com/transport/flight/modern/glider1.htm

Now the criteria that almost cancelled the Osprey project I found to be ludicrous in this design is the transition from vertical to horizontal flight. All six of these rotors must spin synchronously and stop simultaneously at precise angles to the rest of the wing surface or as the rest of the video shows the craft will pitch or roll appropriately. Speaking of the rotors, these are all single blade rotors. The center of mass of each rotor does not align even close to the axis of rotation. The vibrations generated in spinning these blades will surely tear something apart. I also found it ridiculous how the leading rotors are anticipated to articulate without any increased cross-sectional area for a mechanism.

I did like the water skipper video on the same page. That is a novel way to travel across a smooth surface.

well now that you mention it... I think you are right about the small space allowed for power plant and fuel... but as they are comparing it to an SUV, perhaps there is enough space for a 100hp engine and small fuel tank. (short hop)

I thought that they were trying to indicate that the counterweight of the rotors was somewhat dynamic and adjustable in-flight, to account for differences in centrifigual force, based on the difference in radius between the blade and weight.

Im sure that there would be significant design and testing necessary to make it operational... perhaps too much, as experienced in the Moller skycar.

however, I still give points for creativity... without imagination, the problem of small commuter or roadable aircraft will never be solved.

good points.

Chris

We already have enough vehicle accidents from people incapable of handling what I call one plus dimensional motion (1. forward, +. left or right 30°). True three dimensional travel with the much larger easily released potential energy of altitude makes me much more worried than relieved of congestion. Now if airborne taxis were only automatically controlled, then I might go for the concept. This craft looks more like pure fantasy than practical to me.

How about this vehicle for an alternative.

Hi redfred,

I hadn't read your post before posting myself. I had a few of the same observations as you did, namely the CGI appearance and the single-blade rotor imbalance thing. However, you took the time to detail your thoughts. I like your post, so GA.

To add to what you said; hovering out of ground effect, and/or translating from vertical to horizontal flight out of ground effect takes a tremendous amount of power (torque) and results in a LOT of vibration and strain on the power train and airframe.

The Osprey is a mechanical nightmare and it's relatively simple compared to the mechanics required to make this thing work. I just don't see the structure necessary to contain the power train and the control systems, much less engine and fuel. Even if it's conceived to somehow be electrically controlled fly-by-wire you would have to factor in the space required and the weight of redundant computer systems/servos/relays/push-pull tubes/bellcranks/etc needed to make it work.

I also like the "roadable" tag in the title. I wonder what roads they are talking about. This thing would never be certified for US highway driving with what I presume is a thrust engine spewing hot gases out the back end.

Hmmm, I found another video that has some textual detail on the concept.

Click here

Interesting, electric rotors... gotta think about this one.

Hooker

Looks like some clever CGI stuff to me, not to mention the intense imbalance in the "props". Those supports wouldn't last 10 minutes. I like watching Stargate SG1, but that doesn't mean it has anything to do with real science. _{Or reality, for that matter}

Wormhole physics, paugh!

I'm not sure if you are saying that counterweight rotors won't work... but in fact reality invented these things. They are called Maple Keys (seeds) amonst other things, and in Ontario where I grew up, they flutter magically through the air once a year.. and can travel quite a distance in a slight breeze.

and for a proof of concept, see this

Sorry Chris, the maple twirlybirds are not powered, they are passively moving at the wind's whim. It is true that they have been designed to allow them to propagate themselves in a way that ensures their survival.

Those monocopters have low mass, and the COR (center of rotation) is not the axis of the rotor. The only thing that keeps them from flying apart IS their low mass.

Try scaling them up and see what happens!

From my experience in materials strength, the rotor supports (on a hexacopter no less) are not going to hold up for any length of time.

This was just someones "cool" idea who had way too much time on their hands.

"This was just someones "cool" idea who had way too much time on their hands."

well maybe... but we all like flying _{^{( jus goin with the 80's music theme )}}

If I was to choose a Canadian band, it would be these guys!

After all their success, they still have not been inducted into the RRHOF. Does not compute.

http://ultralight-airplanes.info/Gyrocopters-%5E%5E%5E%5E%5E-What-Are-They-And-Can-You-Have-One%5E%5E.html

Seems a lot more practical to me, and a lot closer to my price range...

well ya... but where is the computer animation. As we have already established, the animation is a requirement of modern aviation.

chris

Novel idea but wonder if crash dummies were used in the pilot test!

OK, I see 6 electric motors, possibly a J31 for forward thrust once airborne. As for "roadable" Those wheels would never survive any roads I drive on, so not roadable in my book. Also on the electric motors, so much could go wrong since they would have to have tachs on them so the computer knew what each rev was to keep it level, climb, bank, tilt, hover. Not a simple task and probably out of reach of anyone owning one at all, ever. Plausible experiment, Yes. Practical in any way, fogetaboutit. Love the concept!

It seems all, that is needed to be invented, was. Sorry to be a party pooper. Coaxial by Boeing, not quite coaxial by Kaman. I happened to be partisan to the gyrocopter system of realization. The price is right, the difficulties are right, the failure rate is right. You may be going ahead with this super Osprey. Good luck, and a good godfather.

Interesting concept, Chris, I love flying. But I have problems relating a computer graphic presentation with the real world: 1 How do they handle the balance problem swinging those rotors with the axis at the end of the blade? 2. Where are the rotors powered, and is the horizontal thrust provided by a jet engine? I do not see a propeller. 3. You can do almost anything you want in Wyoming, but have you driven I-95 anywhere between Boston, MA and Richmond, VA or the LIE between the hours of 4:30 - 6:00 pm on a weekday? And you want to add a vertical component to that? No, this one needs to stay in the comic books.

Sounds slightly familiar...

http://www.terrafugia.com/