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#92
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Electrically Powered Ultralight Aircraft
On Aug 8, 8:35 am, Larry Dighera wrote:
On Wed, 08 Aug 2007 07:20:22 -0700, wrote in .com: I have not seen any significant flight duration claim on the Sonex, which speaks well for the design team. I really hate to burst your bubble but, from the Sonex link above. "Initial top speeds will reach approximately 130 mph, and endurance is expected to range between 25-45 minutes or longer, depending upon power usage on each individual flight."- Hide quoted text - - Show quoted text - I also read that but "Expected to be" isn't a claim and 45 minutes is not what I would call significant duration. Would you characterize 12 seconds ad significant? http://www.thewrightbrothers.org/fivefirstflights.html The First Flight, spanning some 120 feet in 12 seconds. The next flight, Wilbur's first flight on the 17th, extended to some 175 feet in 13 seconds and a landing was accomplished with no damage to The Flyer. Orville's second attempt that day, and his last one in The Flyer, carried him just over 200 feet in 15 seconds and ended with a safe landing. At noon, Wilbur took-off on the last and the longest flight which The Flyer would ever make, and flew for 852 feet, staying aloft for 59 seconds. I guess I should have clarified that my comments refer to the here and now where 12 seconds and\or 45 minutes are both insignificant in terms of useful flight duration. While any duration is important the first time achieved it will only become marketable when it has reached a practical use point. Hopefully today's developments will lead to something in the future that is but for now they are interesting engineering experiments. Most people should and do applaud the efforts while some think the future is already here. For those adventurers we have $100,000 cars and underpowered trikes available right now. I'm going to hold off for a little while longer. |
#93
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Electrically Powered Ultralight Aircraft
Larry Dighera wrote:
On Wed, 8 Aug 2007 08:12:37 -0500, "Gig 601XL Builder" wrDOTgiaconaATsuddenlink.net wrote in : They obviously don't make a 100HP motor of the type you showed or you would have quoted it's specs. Take a look at the ~75 HP electric motor installed in the Sonex Waiex: http://www.sonexaircraft.com/news/im...irventure07/e- flight_5947.jpg Exclusive of the two black boxes, the Sonex motor sure doesn't appear to weigh any where near the 1,118 lbs motor you found. My guess would be under 100 lbs. It is custom built for/by Sonex, so I'm not able to quote its specifications. You don't really believe Sonex is using an electric motor that weighs any where near 1,118 lbs, do you. The entire empty weight of the Waiex is only ~620 lbs with a gross weight of 1150 lbs. Of course I don't. But they might as well be at this point becuse the electric motor they have has never been off the ground. I wish the Sonex guys well and will praise the hell out of them if they do what they are trying to do. But, as I said in a earlier post, I just don't see this big of a technological leap coming from a company whose last major enginnering feat was converting a VW engine for aircraft. If and when it happens it will be either a bunch of guys from MIT or Cal Tech or as the offshoot of a much more profitable electric motor project. |
#94
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Electrically Powered Ultralight Aircraft
Larry Dighera wrote:
On Wed, 08 Aug 2007 07:20:22 -0700, wrote in .com: I have not seen any significant flight duration claim on the Sonex, which speaks well for the design team. I really hate to burst your bubble but, from the Sonex link above. "Initial top speeds will reach approximately 130 mph, and endurance is expected to range between 25-45 minutes or longer, depending upon power usage on each individual flight."- Hide quoted text - - Show quoted text - I also read that but "Expected to be" isn't a claim and 45 minutes is not what I would call significant duration. Would you characterize 12 seconds ad significant? http://www.thewrightbrothers.org/fivefirstflights.html The First Flight, spanning some 120 feet in 12 seconds. The next flight, Wilbur's first flight on the 17th, extended to some 175 feet in 13 seconds and a landing was accomplished with no damage to The Flyer. Orville's second attempt that day, and his last one in The Flyer, carried him just over 200 feet in 15 seconds and ended with a safe landing. At noon, Wilbur took-off on the last and the longest flight which The Flyer would ever make, and flew for 852 feet, staying aloft for 59 seconds. I would now but when the best previous powered flight it was ZERO in both time and distance anything 0 was significant. And, unfortunately, for the electric powered airplane folks they have to be compared at least to what I can build in my garage and attach a 1960's vintage Corvair engine too. Sonex's electric airplane especially has to be judged against that criteria because they already make a plane that I can build in my garage and hang a Corvair engine on. |
#95
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Electrically Powered Ultralight Aircraft
Darrel Toepfer wrote:
"Gig 601XL Builder" wrDOTgiaconaATsuddenlink.net wrote: Why should I. I'm not the one making the claim. But your the "bubble burst"r... ;-) Exactly! To have the guys bubble fixed he needs to be the one that keeps an eye out for the flight. |
#96
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Electrically Powered Ultralight Aircraft
On Wed, 8 Aug 2007 10:48:40 -0500, "Gig 601XL Builder"
wrDOTgiaconaATsuddenlink.net wrote in : Larry Dighera wrote: On Wed, 8 Aug 2007 08:12:37 -0500, "Gig 601XL Builder" wrDOTgiaconaATsuddenlink.net wrote in : They obviously don't make a 100HP motor of the type you showed or you would have quoted it's specs. Take a look at the ~75 HP electric motor installed in the Sonex Waiex: http://www.sonexaircraft.com/news/im...irventure07/e- flight_5947.jpg Exclusive of the two black boxes, the Sonex motor sure doesn't appear to weigh any where near the 1,118 lbs motor you found. My guess would be under 100 lbs. It is custom built for/by Sonex, so I'm not able to quote its specifications. You don't really believe Sonex is using an electric motor that weighs any where near 1,118 lbs, do you. The entire empty weight of the Waiex is only ~620 lbs with a gross weight of 1150 lbs. Of course I don't. But they might as well be at this point becuse the electric motor they have has never been off the ground. The motor was apparently designed by Bob Boucher. He also designed the motors Dr. Paul MacCready used to fly across the English channel solely under power from the sun, and other successful AeroVironment electrically powered aircraft commissioned by NASA. If anyone can design a proper electric motor for aviation, Mr. Boucher should be able to; he has the past successes to prove it. I wish the Sonex guys well and will praise the hell out of them if they do what they are trying to do. But, as I said in a earlier post, I just don't see this big of a technological leap coming from a company whose last major enginnering feat was converting a VW engine for aircraft. If and when it happens it will be either a bunch of guys from MIT or Cal Tech or as the offshoot of a much more profitable electric motor project. Perhaps. |
#97
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Electrically Powered Ultralight Aircraft
On Wed, 8 Aug 2007 10:55:38 -0500, "Gig 601XL Builder"
wrDOTgiaconaATsuddenlink.net wrote in : Larry Dighera wrote: On Wed, 08 Aug 2007 07:20:22 -0700, wrote in .com: I have not seen any significant flight duration claim on the Sonex, which speaks well for the design team. I really hate to burst your bubble but, from the Sonex link above. "Initial top speeds will reach approximately 130 mph, and endurance is expected to range between 25-45 minutes or longer, depending upon power usage on each individual flight."- Hide quoted text - - Show quoted text - I also read that but "Expected to be" isn't a claim and 45 minutes is not what I would call significant duration. Would you characterize 12 seconds ad significant? http://www.thewrightbrothers.org/fivefirstflights.html The First Flight, spanning some 120 feet in 12 seconds. The next flight, Wilbur's first flight on the 17th, extended to some 175 feet in 13 seconds and a landing was accomplished with no damage to The Flyer. Orville's second attempt that day, and his last one in The Flyer, carried him just over 200 feet in 15 seconds and ended with a safe landing. At noon, Wilbur took-off on the last and the longest flight which The Flyer would ever make, and flew for 852 feet, staying aloft for 59 seconds. I would now but when the best previous powered flight it was ZERO in both time and distance anything 0 was significant. And, unfortunately, for the electric powered airplane folks they have to be compared at least to what I can build in my garage and attach a 1960's vintage Corvair engine too. Sonex's electric airplane especially has to be judged against that criteria because they already make a plane that I can build in my garage and hang a Corvair engine on. Electrically powered flight is in its infancy just as powered flight was in 1903. |
#98
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Electrically Powered Ultralight Aircraft
Larry Dighera wrote:
Electrically powered flight is in its infancy just as powered flight was in 1903. That matters not. It still has to be compared to what it is supposed to replace. Would you want an electric car that was the technological equal to this? http://www.ausbcomp.com/~bbott/cars/cugnot.jpg. The otherside of that is that we can expect to wait until 2110 for electric flight to catch up to where we are now with gasoline powered flight. |
#99
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Electrically Powered Ultralight Aircraft
Would you characterize 12 seconds ad significant?
http://www.thewrightbrothers.org/fivefirstflights.html The First Flight, spanning some 120 feet in 12 seconds. The next flight, Wilbur’s first flight on the 17th, extended to some 175 feet in 13 seconds and a landing was accomplished with no damage to The Flyer. Orville’s second attempt that day, and his last one in The Flyer, carried him just over 200 feet in 15 seconds and ended with a safe landing. At noon, Wilbur took-off on the last and the longest flight which The Flyer would ever make, and flew for 852 feet, staying aloft for 59 seconds. In 1903 it was but times change... Tony |
#100
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Electrically Powered Ultralight Aircraft
On Tue, 07 Aug 2007 17:51:27 GMT, "Neil Gould"
wrote in : Recently, Larry Dighera posted: [...] I'm thinking there would be necessity for some means of conducting the heat from the engine to a remote heat exchanger, and the resulting complexity and weight increase would negatively impact the potential advantages of a Stirling aviation engine. In any event, in addition to the Stirling engine and its fuel, a heat exchanger of some type needs to factored into the weight, cost, performance, and efficiency equations. Of course, but I don't see a lot of reason why that couldn't be incorporated into the overall design. My point is that heat exchangers need not be heavy, and could probably double as structural and/or aerodynamic components, further reducing (and possibly enhancing) their impact. How would you get the heat from the Stirling engine to the heat sink? If you use liquid coolant, it would be heavy and prone to leaks. There might be one advantage to using Sterling external combustion engines for aviation: the use of atomic energy as a fuel source if the weight of the lead shielding were not too great. Imagine an aircraft that effectively never runs out of fuel! There'd be no more fuel exhaustion mishaps. One downside would be the hazardous materials that could be dispersed in a crash. There are a lot of down sides to atomic power, but NASA uses it to power Stirling engines in space. Understandable, but their expectation is that catastrophic destruction would disperse the nuclear material harmlessly. That can't be presumed for light aircraft. If the rocket detonated in the atmosphere, it might not be so harmless. I would guess the reactor is jacketed with sufficient strength to preclude its destruction. Presumably, that could be done for a Stirling aircraft engine also. |
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