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The future of personal flight?
http://www.gizio.it/cellcraft2.htm The aircraft is equipped with two ALLISON'S gas turbines . Both engine are posed in the posterior niche and connected through a twin transmission box to 4 AXIAL COMPRESSORS. Most of mechanical organs are placed in the niche behind . Gear boxes-transmission are both settled ,one aft and another one in the back of the cockpit ; in-fact each one provide to power a couple of compressors ( two compressors on the front and other two on the back). http://www.gizio.it/verticallinks.htm |
#2
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I know it's not the point, but I'd take these people much more seriously if
they *didn't* have a website full of beautiful renderings of the finished craft. Assuming such a craft is ever possible (given the V-22 experience I wonder) I suspect the devil lies in the systems integration details. Parachutes and airbags in case of engine failure? Has he even thought of what useful load is going to look like when it's all done? Sure, it might fly, but who wants a machine with the fuel burn of an old Lear (at low altitude), the maintenance costs of a big Sikorsky, and the payload of a 172? Well, I hear Moller has a signed purchase agreement with Michael Jackson. 'nuff said. Pretty pictures are the easiest part. It's like a wannabe-novelist who starts by composing a grandiose title with no idea of characters or plot. Though I must admit I was surprised there were no leggy models immediately apparent here, especially given that it's Italian. Disappointed, even. -cwk. "Larry Dighera" wrote in message news ![]() The future of personal flight? http://www.gizio.it/cellcraft2.htm |
#3
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![]() Colin W Kingsbury wrote: Sure, it might fly, but who wants a machine with the fuel burn of an old Lear (at low altitude), the maintenance costs of a big Sikorsky, and the payload of a 172? Speaking of fuel burn, the tanks shown on that illustration probably wouldn't last longer than an hour. George Patterson I prefer Heaven for climate but Hell for company. |
#4
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On Sat, 05 Mar 2005 17:26:33 GMT, "Colin W Kingsbury"
wrote in . net:: Sure, it might fly, but who wants a machine with the fuel burn of an old Lear (at low altitude), the maintenance costs of a big Sikorsky, and the payload of a 172? Who wants a 25 mph aircraft capable of 120 feet long flight of 12 seconds? http://www.infsearch.cs.cmu.edu/cgi-...OVP/204233.wmx It's a start. It portends the future. It's going to need development and refinement, but I believe these vectored thrust machines will eventually be successful in achieving flight and eventually public acceptance. Michael Jackson, on the other hand .... :-) |
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On Sat, 05 Mar 2005 18:51:21 GMT, George Patterson
wrote in :: Colin W Kingsbury wrote: Sure, it might fly, but who wants a machine with the fuel burn of an old Lear (at low altitude), the maintenance costs of a big Sikorsky, and the payload of a 172? Speaking of fuel burn, the tanks shown on that illustration probably wouldn't last longer than an hour. That may be long enough to accomplish its mission. I'll bet it'll be faster than a helo: Bell Jet Ranger --------------- Model: 206B Category: Restricted Engine: Allison C20B Horsepower: 420 Airspeed: 110 knots Range: 3 hours Ceiling: 20,000' msl Max Gross Weight: 3,200 lbs Useable Payload: 1,400 lbs So it's range may be adequate despite limited fuel. I'm encouraged to see some evidence of further advancement of the concept even if it's only on the drawing board now. |
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On Sat, 05 Mar 2005 17:26:33 GMT, "Colin W Kingsbury"
wrote: I know it's not the point, but I'd take these people much more seriously if they *didn't* have a website full of beautiful renderings of the finished craft. Assuming such a craft is ever possible (given the V-22 experience I wonder) I suspect the devil lies in the systems integration details. Parachutes and airbags in case of engine failure? Has he even thought of what useful load is going to look like when it's all done? Sure, it might fly, but who wants a machine with the fuel burn of an old Lear (at low altitude), the maintenance costs of a big Sikorsky, and the payload of a 172? Well, I hear Moller has a signed purchase agreement with Michael Jackson. 'nuff said. Pretty pictures are the easiest part. It's like a wannabe-novelist who starts by composing a grandiose title with no idea of characters or plot. Though I must admit I was surprised there were no leggy models immediately apparent here, especially given that it's Italian. Disappointed, even. I'd give it at least an equal if not greater chance than Moller, but it's going to cost about as much as a PC-12, or TBM-700. Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com -cwk. "Larry Dighera" wrote in message news ![]() The future of personal flight? http://www.gizio.it/cellcraft2.htm |
#7
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![]() "Larry Dighera" wrote in message ... On Sat, 05 Mar 2005 17:26:33 GMT, "Colin W Kingsbury" wrote in . net:: Sure, it might fly, but who wants a machine with the fuel burn of an old Lear (at low altitude), the maintenance costs of a big Sikorsky, and the payload of a 172? It's a start. It portends the future. It's going to need development and refinement, but I believe these vectored thrust machines will eventually be successful in achieving flight and eventually public acceptance. It seems to me that vectored-thrust aircraft face a couple of fundamental challenges that will not be easily overcome. First, you have the poor efficiency of turbines at low speed. The ducted fan approach will improve this somewhat but if you look at the V-22, it has HUGE propellers, more like mini chopper blades. The V-22 may be intended to spend more time in hover than a Mollermobile, but I'll side with the machine that's being flown seriously over the eternal prototype. Second, the powertain complexity is considerable. You need at least 4 nozzles for control, and 2 engines cross-linked to drive the blowers. I'm not a MechE but that sounds like a lot of transmission hardware to manage. What's that statistic I've read about the ratio of shop hours to flight hours for helicopters? This would be much worse. And let's not even get into the control systems. These things would seem to demand pretty sophisticated fly-by-wire and that's going to cost serious money to design and certify, made all the worse by the fact that someone's got to be first. Remember the Starship? FAA conservatism has more than a little to do with why the plane became an albatross, though it also paved the way for planes like the Premier. Again, the V-22 is the best precedent we have to go on here, and the evidence is pretty bad. Twenty-some billion spent as I recall and the things are still nowhere close to deployment. Heck, by that standard the 70 million or so Moller has spent seems like a pretty good investment. Still, I don't see any of these guys solving or even coming close on any of these fundamental problems. Remember the old engineering saying: 90% done, only 90% to go. Software has become fantastically cheap largely because consumers have been willing to put up with 90% done. Aerospace does not enjoy this advantage. There are many technologies that stubbornly refuse to yield to our desire to make them workable. Fusion power, for one. In aircraft, the real area to watch (imho) is pulse-detonatation engines, which if they ever become commercially viable would give us the "Orient Express" planes that take you to Tokyo in a few hours. But Pratt and GE have been working on these for some years, and expect to be working on them for many more, and cannot tell you how close they are to getting it right. As much as I'd like my Jetsons car, I doubt I shall be seeing one anytime soon. -cwk. Michael Jackson, on the other hand .... :-) |
#8
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![]() "Roger" wrote in message ... I'd give it at least an equal if not greater chance than Moller, but it's going to cost about as much as a PC-12, or TBM-700. As much? This thing has 2 engines and much more complicated systems. It'd be quite an achievement to build one at comparable cost to a PC-12. -cwk. |
#9
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On Mon, 07 Mar 2005 05:27:57 GMT, "Colin W Kingsbury"
wrote in et:: "Larry Dighera" wrote in message .. . On Sat, 05 Mar 2005 17:26:33 GMT, "Colin W Kingsbury" wrote in . net:: Sure, it might fly, but who wants a machine with the fuel burn of an old Lear (at low altitude), the maintenance costs of a big Sikorsky, and the payload of a 172? It's a start. It portends the future. It's going to need development and refinement, but I believe these vectored thrust machines will eventually be successful in achieving flight and eventually public acceptance. It seems to me that vectored-thrust aircraft face a couple of fundamental challenges that will not be easily overcome. First, you have the poor efficiency of turbines at low speed. Because the engine(s) of vectored-thrust machines must provide thrust, as they do in conventional aircraft, as well as providing lift, they will never achieve the same economy and efficiency as fixed wing aircraft. I have no idea if turbine or turbofan engines are the best choice for these newly conceived machines; perhaps more efficient diesel or electrical* power plants will be found more efficient in this role. The ducted fan approach will improve this somewhat but if you look at the V-22, it has HUGE propellers, more like mini chopper blades. The V-22 may be intended to spend more time in hover than a Mollermobile, but I'll side with the machine that's being flown seriously over the eternal prototype. If the Wrights had had the same attitude, we'd still be floating around in lighter than air vehicles. :-) Second, the powertain complexity is considerable. You need at least 4 nozzles for control, and 2 engines cross-linked to drive the blowers. Power train complexity could be eliminated with a system of ducts. The Harrier manages with two nozzles. I'm not a MechE but that sounds like a lot of transmission hardware to manage. Nor am I, but the answer may be to eliminate the transmission hardware all together such as independent electric motors powering ducted fans or a single engine with high pressure airflow ducted to (rather than generated at) exit nozzles. Clearly, it's going to take a visionary, creative force able to think outside-the-box to be the enabler for this technology. What's that statistic I've read about the ratio of shop hours to flight hours for helicopters? This would be much worse. My gut feeling is that the vectored-thrust machine, once refined, will probably require slightly more maintenance than a rotary wing. And let's not even get into the control systems. These things would seem to demand pretty sophisticated fly-by-wire and that's going to cost serious money to design and certify, made all the worse by the fact that someone's got to be first. I don't see the control system as being that difficult a hurdle. After all, the Harrier is able to hover with only two nozzles. While fly-by-wire is a new and sophisticated concept for General Aviation, it's been in use for decades on the F-16 and Airbus equipment. As you are no doubt aware, Lockheed intentionally designed the F-16 to be dynamically unstable to facilitate enhanced maneuverability. Then flight stability was artificially programmed into the computerized control system. A similar scheme would be necessary for the machines we are discussing. So while the control system will require research and development, it isn't like it needs to be invented; it already exists. Remember the Starship? FAA conservatism has more than a little to do with why the plane became an albatross, though it also paved the way for planes like the Premier. The Starship** was designed to compete with conventional aluminum aircraft in conducting the same missions those aircraft already had a history of accomplishing reliably. The Starship was a rather unconventional canard design constructed of relatively unproven composite materials. If you were tasked with acquiring aircraft to generate income, would you choose aircraft of known and proven materials and capability, or risk your career/corporation on a new design for which there existed limited repair facilities and mission accomplishment data? Radically new aircraft must have adequate time to prove themselves superior to succeed. Again, the V-22 is the best precedent we have to go on here, and the evidence is pretty bad. Twenty-some billion spent as I recall and the things are still nowhere close to deployment. Heck, by that standard the 70 million or so Moller has spent seems like a pretty good investment. I see the V-22 as being many times larger and heavier than the prototype vehicles we are discussing. Perhaps, of those designs currently existent, a Harrier most closely approaches a reasonable comparison vehicle. But the Harrier has wings and is capable of speeds in excess of those likely to be achieved by the machines we are discussing, so it's nowhere near an exact precedent. Still, I don't see any of these guys solving or even coming close on any of these fundamental problems. Remember the old engineering saying: 90% done, only 90% to go. Software has become fantastically cheap largely because consumers have been willing to put up with 90% done. Aerospace does not enjoy this advantage. It is disappointing indeed that there has been such limited success to date with these designs. Part of the problem is convincing those with the ability to fund such projects that there is a viable market for them by virtue of the unique missions they are capable of accomplishing. Because existing designs are capable of fulfilling most missions, there is little impetus to venture the requisite funding for their development. They look like a good thing, but they don't really do much more than existing aircraft are capable of. In the end, it's going to take an inspired genius like Bert Rutan to pave the way for their development. So far that talent has not emerged. There are many technologies that stubbornly refuse to yield to our desire to make them workable. Fusion power, for one. Personally, I have little doubt that small vectored-thrust aircraft are possible, unlike the prospect of contained fusion reactions. In aircraft, the real area to watch (imho) is pulse-detonatation engines, which if they ever become commercially viable would give us the "Orient Express" planes that take you to Tokyo in a few hours. But Pratt and GE have been working on these for some years, and expect to be working on them for many more, and cannot tell you how close they are to getting it right. Pulse Detonation Rocket Engines*** are throttle controlled rocket engines that have an economical advantage over conventional rocket motors by not requiring an expensive turbopump to overcome the pressure in the combustion chamber to introduce fuel and oxidizer. Indeed rocket power technology may be the future of airline travel. But it must successfully prove itself as economically advantageous, mission enhancing, and safe before it will begin to supplant the current entrenched technology. Because turbine engines are unable to operated in the vacuum of space, pulse detonation technology must only prove it is superior to conventional rocket technology to be deployed there. I see the use of pulse detonation engines being used in space missions long before an attempt is made to use them for airline transportation. As much as I'd like my Jetsons car, I doubt I shall be seeing one anytime soon. That statement reveals the true appeal of the machines we are discussing. They are futuristic dream machines that possess a certain visceral appeal. Science fiction writers dangle them as bait in front of quixotic aviators and the public as they did in The Fifth Element****. Although these machines fail to solve real world missions any better than the current technology, I believe they will eventually be developed as an expression of that playful part of the human spirit that craves the sheer joy of exuberant freedom of personal flight. * http://www.halfbakery.com/idea/Highe...ectric_20Motor ** http://www.aviatorservices.com/starship_history_1.htm *** http://www.msfc.nasa.gov/NEWSROOM/as...e_detonate.pdf **** http://www.imdb.com/title/tt0119116 See them fly he http://videodetective.com/home.asp?PublishedID=7001 |
#10
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("Colin W Kingsbury" wrote)
snips clipped It seems to me that vectored-thrust aircraft face a couple of fundamental challenges that will not be easily overcome. First, you have the poor efficiency of turbines at low speed. The ducted fan approach will improve this somewhat but if you look at the V-22, it has HUGE propellers, more like mini chopper blades. The V-22 may be intended to spend more time in hover than a Mollermobile, but I'll side with the machine that's being flown seriously over the eternal prototype. Again, the V-22 is the best precedent we have to go on here, and the evidence is pretty bad. Twenty-some billion spent as I recall and the things are still nowhere close to deployment. The V-22 Osprey project drives me nuts. V-22 Billion!! (Semper Fi Congressional Industrial Complex) The 1950's Fairey Rotodyne worked. They even had orders. It was flying around Europe, hauling people and freight, in the late 50's and early 60's. This thing was designed over 50 years ago. Can you imagine new engines, new composites, new engineering concepts, new rotors, new electronics, etc? I don't know exactly what the design/mission specs are (were) for the V-22, but I suspect the Rotodyne came close to meeting some of them, while outdoing others. The Rotodyne was successfully flying. Tweak it, and you've got something. Start fresh and you have $22 BBBBillion worth of nothing. What a sad joke. Apparently, because of the way the jets on the rotor tips work, there is no need for a tail rotor. Also, the rotor goes into autogyro mode when the plane reaches a certain forward speed. The rotor-tip jets kick in for take-off and landing only. Jet thrust is provided by bleed air from the turboprop engines, located on the Rotodyne's stubby wings. Reason I've read for its demise was fear of noise pollution (Right, like a 1st generation 707 wasn't loud? And what about those 2 Harrier jump-jet at OSH last year?). Another reason I've read for the project's cancellation was British Govt. inside politics - with Fairey being outside. http://www.hofstra.edu/CampusL/Cultu...iro_movies.cfm Fairey Rotodyne movie on bottom of page http://www.dunnbypaul.net/aircraft/rotodyne/ Rotodyne info http://avia.russian.ee/vertigo/fairey_rotodyne-r.html Rotodyne page http://www.hofstra.edu/CampusL/Cultu...llery20_22.cfm X-game simulations are fun Montblack |
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