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#11
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Lancair Legacy Design Flaw?
Look at the picture. It's easy to see why the Lancair is dangerous. The horizontal stabilizers appear to be on the too small side. This would result in their stalling before the wing. Then the aircraft would pitch up making the main wing stall. Ill-conceived, IMO. ************************************************** ************* Any one ever look at the little tail on the ME-109? A bitch to land but was told that was caused by the main gear configuration. Big John |
#12
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Lancair Legacy Design Flaw?
On Oct 29, 11:46*am, Alan Baker wrote:
In article , *"Gregory Hall" wrote: "Bryan Martin" wrote in message ... That could only happen if the plane was loaded with the CG way aft of the limit. Otherwise, the plane would pitch DOWN if the stabilizer stalled because the stabilizer normally produces a down force to keep the nose up. If it worked that way it would be a built-in safety factor helping to forestall a stall of the main wing. But suppose the motor died and the aircraft was then a glider. One must glide nose down. The horizontal stabilizer forcing the nose down would then cause the pilot to pull back on the stick to counteract the forces for aft. If the stabilizer stalled in this attitude the nose is supposed to pitch down but would it? The tail might just continue to drop provided the main wing still gets traction??? CG is dependent upon both lifting both control surfaces as well as weight distribution. Sorry. But centre of *mass* (to use the correct term) is not in any way dependent on the lift from anything. The centre of mass is a parameter than is completely fixed by the distribution of the mass of the aircraft's components. Whether any surface is providing lift will not change it. So as long as the main wing is located aft of the centre of mass, the aircraft will pitch *down* when lift from the tail plane is lost. Period. -- Gregory Hall In article , "Gregory Hall" wrote: http://www.youngeagles.org/photos/ga...ncairLegacy200... Look at the picture. It's easy to see why the Lancair is dangerous. The horizontal stabilizers appear to be on the too small side. This would result in their stalling before the wing. Then the aircraft would pitch up making the main wing stall. Ill-conceived, IMO. A good lawyer needs to get on this with respect to BadWaterBill's untimely demise. -- Gregory Hall -- Bryan Martin N61BM, CH 601 XL, Ram Subaru, Stratus redrive. -- Alan Baker Vancouver, British Columbia http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg It's kinda simple. Assuming the main wheels are under the wing and the a/c still rests on those and the nose wheel then wings are aft of the cg and the horizontal stabilisers are there for down force to keep the nose up. Not sure what Gregory is banging on about here. |
#13
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Lancair Legacy Design Flaw?
In article
, JohnO wrote: On Oct 29, 11:46*am, Alan Baker wrote: In article , *"Gregory Hall" wrote: "Bryan Martin" wrote in message ... That could only happen if the plane was loaded with the CG way aft of the limit. Otherwise, the plane would pitch DOWN if the stabilizer stalled because the stabilizer normally produces a down force to keep the nose up. If it worked that way it would be a built-in safety factor helping to forestall a stall of the main wing. But suppose the motor died and the aircraft was then a glider. One must glide nose down. The horizontal stabilizer forcing the nose down would then cause the pilot to pull back on the stick to counteract the forces for aft. If the stabilizer stalled in this attitude the nose is supposed to pitch down but would it? The tail might just continue to drop provided the main wing still gets traction??? CG is dependent upon both lifting both control surfaces as well as weight distribution. Sorry. But centre of *mass* (to use the correct term) is not in any way dependent on the lift from anything. The centre of mass is a parameter than is completely fixed by the distribution of the mass of the aircraft's components. Whether any surface is providing lift will not change it. So as long as the main wing is located aft of the centre of mass, the aircraft will pitch *down* when lift from the tail plane is lost. Period. snip It's kinda simple. Assuming the main wheels are under the wing and the a/c still rests on those and the nose wheel then wings are aft of the cg and the horizontal stabilisers are there for down force to keep the nose up. Not sure what Gregory is banging on about here. Well, it's not quite *that* simple. There's no rule that the wheels need to be directly under the centre of lift of the wing, but yeah... ....basically that's it. I have no idea how anyone can get the wrong headed idea that the centre of mass of a rigid body can move around. -- Alan Baker Vancouver, British Columbia http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg |
#14
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Lancair Legacy Design Flaw?
"Gregory Hall" wrote in message ... http://www.youngeagles.org/photos/gallery/Monoplanes/LancairLegacy2000.jpg Look at the picture. It's easy to see why the Lancair is dangerous. The horizontal stabilizers appear to be on the too small side. This would result in their stalling before the wing. Then the aircraft would pitch up making the main wing stall. Ill-conceived, IMO. I find your strange posting to be quite offensive in its serious charges which are totally unfounded. As others have already pointed out, you are fundamentally incorrect about the purpose of the horizontal stabilizer. The horizontal tail holds the nose up, not down. Your assertion about the Legacy's stall recovery just makes no sense at all. By the way, the Lancair Legacy is the most fun civilian airplane I've flown and is the main reason I returned to general aviation after a decades-long absence. I'm sure there is a Legacy near you and I'll bet its pilot would be happy to take you for a ride. You can see for yourself what a great airplane it is. Dennis |
#15
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Lancair Legacy Design Flaw?
On Tue, 28 Oct 2008 15:41:35 -0400, "Gregory Hall" wrote:
http://www.youngeagles.org/photos/gallery/Monoplanes/LancairLegacy2000.jpg Look at the picture. It's easy to see why the Lancair is dangerous. The horizontal stabilizers appear to be on the too small side. This would result in their stalling before the wing. Then the aircraft would pitch up making the main wing stall. Ill-conceived, IMO. A good lawyer needs to get on this with respect to BadWaterBill's untimely demise. Unfortunately, there are several factors at work that would reduce the chance of success in a lawsuit against Lancair. First, of course, there's nothing to say the size of the horizontal tail had any bearing on this accident. Second, Bill had been flying this aircraft for several years with nothing but praise for the way it handled. Third, Lancair wasn't the manufacturer of this airplane. All they did was supply parts. Finally, the situation is strongly muddied by the fact that aircraft was built by a hired gun. The FAA doesn't list the certification category for Bill's airplane (not uncommon...John Ammeter's RV-6 was the same way). But the builder of his plane built two other Lancair Legacies completed at the same time as Bill's and registered them as Amateur-Built (N36XX and N272AG). *If* N151HT was also carried an Amateur-Built registration, I think Lancair would have a strong case that the airplane was built under fraudulent circumstances. I think it would be hard to show that Bill was unaware of it... http://tinyurl.com/5atovq ....and I suspect most judges wouldn't be sympathetic. Ron Wanttaja |
#16
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Lancair Legacy Design Flaw?
Ron Wanttaja wrote:
But the builder of his plane built two other Lancair Legacies completed at the same time as Bill's... I'd meant to post "at *about* the same time." Bill's was completed in early 2006, Legacy N36XX is also listed as a 2006 model, and Legacy N272AG as a 2007. N36XX has a co-manufacturer listed and has a significantly lower serial number; I'd speculate that this might have been a previously-started project. Legacy N272AG and Legacy N151HT have serial numbers just five numbers apart (L2K-267 and L2K-272). Ron Wanttaja |
#17
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Lancair Legacy Design Flaw?
"Dennis Johnson" wrote in message . .. "Gregory Hall" wrote in message ... http://www.youngeagles.org/photos/gallery/Monoplanes/LancairLegacy2000.jpg Look at the picture. It's easy to see why the Lancair is dangerous. The horizontal stabilizers appear to be on the too small side. This would result in their stalling before the wing. Then the aircraft would pitch up making the main wing stall. Ill-conceived, IMO. I find your strange posting to be quite offensive in its serious charges which are totally unfounded. As others have already pointed out, you are fundamentally incorrect about the purpose of the horizontal stabilizer. The horizontal tail holds the nose up, not down. Your assertion about the Legacy's stall recovery just makes no sense at all. I think it makes good sense. Look at the size of that engine up front. Looks like a P-51 Mustang for pity sake. When you're being pulled along by that big prop and heavy, powerful engine it pulls the nose of the aircraft down. The horizontal stabilizers have to counteract this force by putting an upward force on the nose by pushing the tail down. If and when the engine suddenly dies the aircraft will pitch up suddenly and since the size of the stabilizers are so puny they might easily stall and be unable to counteract the upward pitch at the nose resulting in a tail down death spiral. By the way, the Lancair Legacy is the most fun civilian airplane I've flown and is the main reason I returned to general aviation after a decades-long absence. I'm sure there is a Legacy near you and I'll bet its pilot would be happy to take you for a ride. You can see for yourself what a great airplane it is. It looks too much like an irresponsible, hot rod, stunt plane to me. Is it any wonder so many companies offering homebuilt aircraft have gone out of business? http://www.homebuilt.org/aircraft/nolonger.html This is the safest homebuilt IMO.(VariEze ). The canard makes it foolproof. http://video.google.com.au/videoplay...77166441&hl=en -- Gregory Hall |
#18
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Lancair Legacy Design Flaw?
"Gregory Hall" wrote in message ... It looks too much like an irresponsible, hot rod, stunt plane to me. Well, you sucked me in at first, so on a troll scale of zero-to-10 you rate at least a five. How are things in France? Vaughn |
#19
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Lancair Legacy Design Flaw?
In article ,
"Gregory Hall" wrote: "Dennis Johnson" wrote in message . .. I find your strange posting to be quite offensive in its serious charges which are totally unfounded. As others have already pointed out, you are fundamentally incorrect about the purpose of the horizontal stabilizer. The horizontal tail holds the nose up, not down. Your assertion about the Legacy's stall recovery just makes no sense at all. I think it makes good sense. It makes absolutely backwards sense. You need to do a bit more handwaving. Really. Better, go find a local park and play on the teeter-totter for a while. I'm serious. Look at the size of that engine up front. Looks like a P-51 Mustang for pity sake. For fairly vague, and small, values of "P-51". When you're being pulled along by that big prop and heavy, powerful engine it pulls the nose of the aircraft down. Even when the engine is not running, it's pulling the nose down. It's called "weight", and it's constant. The horizontal stabilizers have to counteract this force by putting an upward force on the nose by pushing the tail down. Good so far. If and when the engine suddenly dies the aircraft will pitch up suddenly Nope. It will pitch *down* as the aircraft decelerates. Think about it; the airflow over the stabilizer/stabilator/tail feathers provides the down force at one end of the lever to compensate for the downforce (engine/prop) at the other end of the lever. Slow down and the down force at the tail end decreases, so that the down force provided by the engine/prop is no longer exactly counterbalanced. The aircraft will begin to accelerate downward as it pitches down (*not* up). Given time and altitude, it will eventually stabilize in a descent, at whatever speed it was trimmed for at the time the engine quit. and since the size of the stabilizers are so puny they might easily stall and be unable to counteract the upward pitch at the nose resulting in a tail down death spiral. How in the world do you get this upward pitch? The engine is heavy, not lighter than air, you know. By the way, the Lancair Legacy is the most fun civilian airplane I've flown and is the main reason I returned to general aviation after a decades-long absence. I'm sure there is a Legacy near you and I'll bet its pilot would be happy to take you for a ride. You can see for yourself what a great airplane it is. It looks too much like an irresponsible, hot rod, stunt plane to me. Looks like an aircraft designed for moderately high cruise speeds. Is it any wonder so many companies offering homebuilt aircraft have gone out of business? http://www.homebuilt.org/aircraft/nolonger.html They mostly failed due to not enough customers, or by being inadequately capitalized, and for other business reasons. Or are you arguing that aircraft similar to the old Aeronca 7AC, Chief or Sedan are gone now because they were all "irresponsible, hot rod, stunt planes"? [ Say, you're not related to the fellow who was trying to drum up support for closing down airpark housing developments for being too dangerous, are you? ] This is the safest homebuilt IMO.(VariEze ). The canard makes it foolproof. http://video.google.com.au/videoplay...77166441&hl=en Tell it to some users of that type of aircraft who found more excitement than they'd bargained for if they flew into light rain... Or, say, John Denver, who was killed flying one a couple years back. The canard didn't save him, did it? As for your movie, do you have any idea what the aircraft's sink rate might be while it isn't stalling there? |
#20
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Lancair Legacy Design Flaw?
In article ,
"Gregory Hall" wrote: "Dennis Johnson" wrote in message . .. "Gregory Hall" wrote in message ... http://www.youngeagles.org/photos/ga...Legacy2000.jpg Look at the picture. It's easy to see why the Lancair is dangerous. The horizontal stabilizers appear to be on the too small side. This would result in their stalling before the wing. Then the aircraft would pitch up making the main wing stall. Ill-conceived, IMO. I find your strange posting to be quite offensive in its serious charges which are totally unfounded. As others have already pointed out, you are fundamentally incorrect about the purpose of the horizontal stabilizer. The horizontal tail holds the nose up, not down. Your assertion about the Legacy's stall recovery just makes no sense at all. I think it makes good sense. Look at the size of that engine up front. Looks like a P-51 Mustang for pity sake. When you're being pulled along by that big prop and heavy, powerful engine it pulls the nose of the aircraft down. The horizontal stabilizers have to counteract this force by putting an upward force on the nose by pushing the tail down. If and when the engine suddenly dies the aircraft will pitch up suddenly and since the size of the stabilizers are so puny they might easily stall and be unable to counteract the upward pitch at the nose resulting in a tail down death spiral. More nonsense. The loss of thrust won't result in a sudden pitch-up. The engines mass and the force of gravity acting on that mass don't disappear when it stops producing power. By the way, the Lancair Legacy is the most fun civilian airplane I've flown and is the main reason I returned to general aviation after a decades-long absence. I'm sure there is a Legacy near you and I'll bet its pilot would be happy to take you for a ride. You can see for yourself what a great airplane it is. It looks too much like an irresponsible, hot rod, stunt plane to me. Is it any wonder so many companies offering homebuilt aircraft have gone out of business? http://www.homebuilt.org/aircraft/nolonger.html This is the safest homebuilt IMO.(VariEze ). The canard makes it foolproof. http://video.google.com.au/videoplay...77166441&hl=en Anyone who thinks an aircraft can be made "foolproof" is a fool who shouldn't be flying. -- Alan Baker Vancouver, British Columbia http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg |
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