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#41
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IKYABWAI..
Rich Ahrens wrote in news:48790786$0$60071
: on 7/12/2008 1:39 PM Bertie the Bunyip said the following: "Maxwell" luv2^fly99@cox.^net wrote in : "Bertie the Bunyip" wrote in message ... You don't need those drugs, Maxie, you just need a bit of electro shock. Try sticking your tongue in a light socket. You'll not only enjoy it, you'll notice the difference n your outlook in a matter of days, if not hours. Bertie Sounds like the voice of experience to me. Now we know the rest of the story. Good day! Awww, IKYABWAI lames. You adorable! You have quite the chewtoy there, Bertie! I think you can set the drag on high with this one and he won't throw the hook. Absolutely. You don't get one like this every day! Bertie |
#42
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Prop angle of attack vs age
"Bertie the Bunyip" wrote in message ... Oh sorry, i thought you were talking about the improvements on the tailwind. Never heard of anything like that before Try to keep up dumb ass. |
#43
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Prop angle of attack vs age
"Maxwell" luv2^fly99@cox.^net wrote in news:ADaek.20360$%q.1443
@newsfe24.lga: "Bertie the Bunyip" wrote in message ... Oh sorry, i thought you were talking about the improvements on the tailwind. Never heard of anything like that before Try to keep up dumb ass. Do give us a dissertation on efficiency luser boi. Bertie |
#44
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Prop angle of attack vs age
On Sat, 12 Jul 2008 08:45:36 -0700 (PDT), More_Flaps
wrote: On Jul 13, 12:53*am, wrote: On Jul 12, 8:37*am, Stealth Pilot wrote: On Fri, 11 Jul 2008 06:00:22 -0700 (PDT), wrote: On Jul 11, 7:09*am, Stealth Pilot wrote: On Fri, 11 Jul 2008 08:57:13 +0000 (UTC), Bertie the Bunyip wrote: sid wrote in news:702f8b8d-b77e-452c-904c- : On older planes, does the angle of attack change ? Does the prop angle relax like a motorboat prop does after 1 or 2 decades of constant use ? (fixed pitch of course) There are some older warriors on the field (20 - 25) years, and it seems that there props don't have the bite that the new warrior (10 years old) does. No, but years of wear and dressing the prop because of nicks and what not doesn't do them any good at all. Bertie I have a fibreglass covered wooden prop which makes it reasonably resilient in light rain. I paint it. when the aforesaid light rain has eroded the paint *near the leading edge I lose 5 knots in cruise speed. also If I alter the shape with a poor paint coat I lose cruise speed. the other factor with some commercial aircraft is that there are often 3 props approved for them. a climb, a utility and a cruise prop. on little cessnas they are each 2 inches of pitch apart. memories of cruise with a cruise prop would make cruise on a climb prop seem quite anaemic. ....and what bertie wrote. Stealth Pilot I can understand why a poor -- as in not smooth -- paint job would alter the prop's efficiency, but never would have guessed having a fractional mm of paint ablated from the leading edge of the prop would affect it that much. Tongue in cheek question -- did the natural color of the prop clash with that color and scare the air, or something? On a serious note, have you any thoughts as to why such a minor change in shape would have such a remarkable change in efficiency? A 5 knot change in airspeed is like reducing the manifold an inch or so, isn't it? That's huge! It also suggests there may be very minor changes in prop that could improve performance too. l the prop had a fairly average sheath put on it. average workmanship. I use the paint layers to fair the surface to a smoother shape. the face I see is painted matte black to make it invisible. the leading edge is blue, the rest varnish. chipped paint just creates a turbulator which seems to affect this blade section. (clark Y, aka naca 44xx series) I got 5 extra knots in cruise for nothing when I cleaned up the prop and got the shape right the first time. the damaged leading edge paint just drops me back to the original slower cruise. Stealth Pilot Five knots is a huge gain. I remember reading some years ago of a homebuilt getting a new paint job, and the color change on the wings led to a paint 'bump' or seam near the leading edge which so altered the airflow the airplane could not fly (probably changed the stagnation line). Sounds like a myth to me. How thick is a paint line? not a myth at all. it was a well documented problem on one of the early fibreglass canards. the addition of a decorative tape stripe on the top of the canard resulted in the aircraft not being able to takeoff. removal of the stripe fixed the problem. in an allied situation a friend complained of a sudden 45 knot reduction in the speed of his RV6. it really put the wind up him. a cursory inspection and I could see that the heavyweight polyurethane protective tape he'd applied to the prop had destroyed the aerofoil shape. he removed it at my suggestion and immediately had his 45 knots back. remember being told to remove frost from the wings before flight? more than one aircraft has crashed because they didnt. same effect. Stealth Pilot |
#45
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Prop angle of attack vs age
On Sat, 12 Jul 2008 18:25:42 +0000 (UTC), Bertie the Bunyip
wrote: I got 5 extra knots in cruise for nothing when I cleaned up the prop and got the shape right the first time. the damaged leading edge paint just drops me back to the original slower cruise. Stealth Pilot Five knots is a huge gain. I remember reading some years ago of a homebuilt getting a new paint job, and the color change on the wings led to a paint 'bump' or seam near the leading edge which so altered the airflow the airplane could not fly (probably changed the stagnation line). Sounds like a myth to me. How thick is a paint line? Still, that big a change in cruise speed seems remarkable. I'd say unlikely. Not in an airplane like the Tailwind. A small change in somethign like a Cherokee might not get you much, though a series of changes will get you quite a lot evn in one of those, but something that acts more of a whole like a talwind or a Midget mustang can be hugely affected by one single ingredient being out. Bertie on an allied note there was a cherokee that had been flown up in the North of Australia all it's life. every year to protect the aircraft the owner had hand painted it. the paint eventually looked so crappy that when it was sold the new owner immediately put it into the paint shop. the painters were intrigued by the thickness of the paint. on careful examination made easier because each year it was painted a new colour the painters discovered that it had 26 distinct layers of paint. needless to say the professional paint job removed all of this re alodined the skin and applied the thin paint coats. the new owner reported that after repainting it felt like the aircraft had an extra 50 horsepower. paint matters. Stealth Pilot |
#46
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Prop angle of attack vs age
On Sat, 12 Jul 2008 13:41:49 -0500, "Maxwell" luv2^fly99@cox.^net
wrote: "Bertie the Bunyip" wrote in message .. . Snort! I'm so far ahead of you i know what you had for lunch next thursday. It will be Spaghetti-ohs, BTW Bertie You're a legend in your own mind. maxwell you are such a dimwit that if bertie was as thick as two short planks he'd still be brilliant compared to you. god you're a f@@@@@@t. Stealth pilot |
#47
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Prop angle of attack vs age
Stealth Pilot wrote in
: On Sat, 12 Jul 2008 18:25:42 +0000 (UTC), Bertie the Bunyip wrote: I got 5 extra knots in cruise for nothing when I cleaned up the prop and got the shape right the first time. the damaged leading edge paint just drops me back to the original slower cruise. Stealth Pilot Five knots is a huge gain. I remember reading some years ago of a homebuilt getting a new paint job, and the color change on the wings led to a paint 'bump' or seam near the leading edge which so altered the airflow the airplane could not fly (probably changed the stagnation line). Sounds like a myth to me. How thick is a paint line? Still, that big a change in cruise speed seems remarkable. I'd say unlikely. Not in an airplane like the Tailwind. A small change in somethign like a Cherokee might not get you much, though a series of changes will get you quite a lot evn in one of those, but something that acts more of a whole like a talwind or a Midget mustang can be hugely affected by one single ingredient being out. Bertie on an allied note there was a cherokee that had been flown up in the North of Australia all it's life. every year to protect the aircraft the owner had hand painted it. the paint eventually looked so crappy that when it was sold the new owner immediately put it into the paint shop. the painters were intrigued by the thickness of the paint. on careful examination made easier because each year it was painted a new colour the painters discovered that it had 26 distinct layers of paint. needless to say the professional paint job removed all of this re alodined the skin and applied the thin paint coats. the new owner reported that after repainting it felt like the aircraft had an extra 50 horsepower. paint matters. On a prop, definitely. I'm sure the thing was getting a substantial boost in HP if the revs were down static! Bertie |
#48
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Prop angle of attack vs age
Stealth Pilot wrote in
: On Sat, 12 Jul 2008 08:45:36 -0700 (PDT), More_Flaps wrote: On Jul 13, 12:53*am, wrote: On Jul 12, 8:37*am, Stealth Pilot wrote: On Fri, 11 Jul 2008 06:00:22 -0700 (PDT), wrote: On Jul 11, 7:09*am, Stealth Pilot wrote: On Fri, 11 Jul 2008 08:57:13 +0000 (UTC), Bertie the Bunyip wrote: sid wrote in news:702f8b8d-b77e-452c-904c- : On older planes, does the angle of attack change ? Does the prop angle relax like a motorboat prop does after 1 or 2 decades of constant use ? (fixed pitch of course) There are some older warriors on the field (20 - 25) years, and it seems that there props don't have the bite that the new warrior (10 years old) does. No, but years of wear and dressing the prop because of nicks and what not doesn't do them any good at all. Bertie I have a fibreglass covered wooden prop which makes it reasonably resilient in light rain. I paint it. when the aforesaid light rain has eroded the paint *near the leading edge I lose 5 knots in cruise speed. also If I alter the shape with a poor paint coat I lose cruise speed. the other factor with some commercial aircraft is that there are often 3 props approved for them. a climb, a utility and a cruise prop. on little cessnas they are each 2 inches of pitch apart. memories of cruise with a cruise prop would make cruise on a climb prop seem quite anaemic. ....and what bertie wrote. Stealth Pilot I can understand why a poor -- as in not smooth -- paint job would alter the prop's efficiency, but never would have guessed having a fractional mm of paint ablated from the leading edge of the prop would affect it that much. Tongue in cheek question -- did the natural color of the prop clash with that color and scare the air, or something? On a serious note, have you any thoughts as to why such a minor change in shape would have such a remarkable change in efficiency? A 5 knot change in airspeed is like reducing the manifold an inch or so, isn't it? That's huge! It also suggests there may be very minor changes in prop that could improve performance too. l the prop had a fairly average sheath put on it. average workmanship. I use the paint layers to fair the surface to a smoother shape. the face I see is painted matte black to make it invisible. the leading edge is blue, the rest varnish. chipped paint just creates a turbulator which seems to affect this blade section. (clark Y, aka naca 44xx series) I got 5 extra knots in cruise for nothing when I cleaned up the prop and got the shape right the first time. the damaged leading edge paint just drops me back to the original slower cruise. Stealth Pilot Five knots is a huge gain. I remember reading some years ago of a homebuilt getting a new paint job, and the color change on the wings led to a paint 'bump' or seam near the leading edge which so altered the airflow the airplane could not fly (probably changed the stagnation line). Sounds like a myth to me. How thick is a paint line? not a myth at all. it was a well documented problem on one of the early fibreglass canards. the addition of a decorative tape stripe on the top of the canard resulted in the aircraft not being able to takeoff. removal of the stripe fixed the problem. Yeah, I remember that. On the flip side of that the additin of a turbulator strip in the right place will enhance lift.. http://www.standardcirrus.org/Turbulators.html Bertie |
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