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madras tips

1. trying different tips on each wing is a waste of testing time. It is an in-valid test. (we can argue this later, if any one cares to)

Yep, heard the same thing from Steve Wittman himself as well as several others whom I respect their opinion.

What people have to realize is that everyone has a different mission for their airplane.
 
My first cub had square tips, Hendrickson (sp?) I think. It stalled with a dramatic break, and you could not fly it down close to stall on approach, because if you did and it stalled, you were a statistic.

My current plane with round tips has a slight burble at stall, so I can fly it right down to the burble and add 25 rpms and continue, no nose down break, so it is not the risk of life and limb...

The square wings with more area gave more lift, but the round tips allowed me to use the lift I had to a better advantage, and once down I can kill my lift and get on my breaks better for a shorter stop... I actually fly this plane slower on approach...

That said, I do have vg's and thrustline on this bird now. It is set up the way I want it, and I like it. I never got to fly a plane with, then without tips to check, but my friends did some testing, including putting one Madras tip up, and the other side down, and could not detect a single change.

Were I building a plane to win Valdez, and nothing else, I might have the tips on, or put a big piece of plate out there sticking up 2" and down six inches to stop the flow around the tip...

for practical use, I would bet that most of us could not measure the difference in performance between the droop tips and other square wing tips.

But round wings shed brush better!:peeper

And they look a whole lot better to purists:9mm:9mm

(back to my hole)
what i'm getting out of this it seems the burble (pigtail) at the end of the wing(round tip)
creates drag ,so if the wing is paying off slower (stills wants to fly) .you would need more power (speed) to take off with a square tips to gain greater lift? i had a L16a that at stall would pay off quick(cleaner) than my cub that still likes to fly or float to the end of stall, so Q's is with square tips does a cub not float (quicker or cleaner stall)? pays off cleaner and more lift? and i'm starting to ask myself why are there not more of them being used ? to much work, looks,not much gain?,and i know the airfowls are not the same, cub vs champ let me know thanks
 
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If the Husky test pilot actually felt that a different tip on each wing was a valid test, I seriously doubt any data that comes from Aviat. Dave Calkins is correct. Jerry B.
 
hay scooter have you flown a 12 with stock tips to compare? slowflight, stall, etc. i know no 2 planes are the exact same but close, let me know thanks

Yes I have flown 4-5 other -12s with flaps, but no VGs and standard piper wingtip bows. As you said there is far to many variables in -12's, some are real dogs, some are decent flyers. One stock tipped -12 of a friend of mines was a good flyer too, but had more hard-break stall characteristics, and not as good of aileron control as mine, particularly with the wing fully stalled. I have never parted with my -12 in 33 years as it is a good flying -12 and I know how it flies very well due to all my time in it.
 
My inexperienced/uneducated take on this:
The top of the wing creates lift by creating a low pressure, compared to the bottom with a high(er) pressure.
Anything that helps to increase the DIFFERENCE in those pressures is gonna help "lift" that wing.
The air moving under the wing tends to slip toward the wingtip... so if you can help to prevent that air easily slipping off the tip, you're increasing the "pressure" under the wing, no? Maybe not much, but bound to help, s'pecially when slow.

As to those who feel their view is blocked, how far do you haft'a move your stick to peek under? Even with a stock wing I like to lift it a bit to peek before I turn that'a way.
My droopy tips were there when I bought the plane, and I remember feeling "that's a good thing". Bird wings are kinked (drooped) from the middle!
And they can turn downwind no prob!
[ducking/running]
 
Logan, bald and golden eagle wingtips aren't bent down.:)


.....and they spend alot of their lives "wheeling" around a wingtip in slow flight climbing in thermals. :)
 
Jerry Burr had some great pictures of a tufted stock wing tip and droop tip in slow flight. The stock tip had the air spilling off the end and the droop tip had the air going aft over the aileron.
 
Now why are all these modern airplanes going to winglets where there pointing them up instead of down? What would happen if they were put on backwards were there pointing up instead? Just a dumb question.
 
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L16abe
You have thrown the Champ into the mix. I had a Champion 7GCB, flaps and 150hp. It was no Super Cub. I installed a set of Ferguson droop tips which are similar to the Madras. The smaller tip rib was removed and a full sized rib was mounted at the tips of the spars with the droop tip attached to this rib. The takeoff, climb and cruise performance was greatly improved. The sloppy Champ aileron control changed to a very positive Cub like aileron response. Before the tips the stick could be moved left/right rapidly without moving the wing. With the tips, when this was done, the wing responded immediately. I had a friend with a stock 150 PA-18 which, before the tips, would always outperform the Champ. After the tips were installed they were close to the same with the Cub having a slight edge. I liked the tips on the 7GCB. I also had a PA-18-90 with drooped tips and flaps. Never flew it without the droops. Both were good performers. Perhaps the slight increase in wing area with the full sized airfoil to the tip made all the improvement? I don't know. I agree that if you are flying in close proximity to the ground and/or a buddy in another plane your visibility is restricted, beyond that visibility was not a concern.
 
Now why are all these modern airplanes going to winglets where there pointing them up instead of down? What would happen if they were put on backwards were there pointing up instead? Just a dumb question.

The winglets reduce the wingtip vortices which of course will give you lower stall speed as the laminar flow on top of the wing is undisturbed.
Some are also shaped in a way to channel the wingtip vortex down and out, adding small amount of thrust and reducing fuel consumption. But I doubt you'd see that in anything but a jet. Although Wilga 2000 have winglets claimed for increased fuel economy, so maybe I'm wrong.
 
Now why are all these modern airplanes going to winglets where there pointing them up instead of down? What would happen if they were put on backwards were there pointing up instead? Just a dumb question.

If you are talking 'Hoerner' style wing tips a la Air Tractor, then they are just another way to skin the same cat.
If you are talking winglets a la Gulfstream, they are used for killing two birds with one stone. They do aid lift by killing the air spill , but the more important aspect of their use in the ag bizz is the change in the vorticies shape and deposition. They are shaped as an airfoil as well, which generates it's own vortex, but the location and effect of this vortex on the main vortex, is supposed to kill some of the over all induced drag. They also load the wing in ways it was not designed for, consequently some outfits will not work on your airplane if it has them on it. I have a few thousand hrs.in an aircraft that had them, and now has a stock wing with vg.s. My experience is that it flew a tad better with them, and had a better pattern as well. But was probably not worth the weight or effort. I seriously doubt any such wingtip would be worth it's effort on a cub type.

Pattern testing a 400 gal. plane I used to fly at 20 GPA:
normal_IMG_1234a-12-28-03.JPG


This is my current ride (510) with the old wings:
normal_rockwell_city_004.JPG


Flew this Garret powered one for a while, but never without the winglets:
normal_Kings_ranch.jpg

Take care, Rob
 
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Rob, you put them on upside down. They are row markers like a corn planter, then you don't need a satloc... They got taken off a lot of AT's. Don't know if it was the AD or pilot preference or both.
 
Rob, you put them on upside down. They are row markers like a corn planter, then you don't need a satloc... They got taken off a lot of AT's. Don't know if it was the AD or pilot preference or both.

To be completely honest, about the only thing I really miss about them is the reflection off the strobes on night work. There is something to be said for knowing exactly where you wing ends when trimming up along a wire or trees...that, and the plane was a tad more stable in bad air...

That said we both know everyone going to or coming from Olney is 'snowed' :lol:
I understand AT won't work on anything with ag tips, unless they are removing them.
 
Up swept versus Down swept tips.
I had some of these same questions a while back and came up with these answers. If anyone else has done similar research on the matter I would be glad to read it. Opinions excepted.
The upsweep on the jets has a lot to do with the tapered wing and winglet fooling the air into thinking the wing is a lot longer. If the wing were extended to a point it also would be more efficient, but a real pain to taxi around crowded airports. The winglet is a great comprise for a tapered wing. And some winglets do create thrust at cruise speeds. If we reverse a droop like the Demer so it curves up instead of down, it will create a standing vortice above and outboard of the tip. This will have a tendency to contain the low pressure above the wing, which is probably more important than maintaining the high pressure under the wing. It will actually use both pressures to maintain the vortex. This vortex will impede the ambient air outboard of the wing from trying to fill the low pressure above the wing at the expense of losing the somewhat high pressure under the wing. This loss of under wing pressure would be most pronounced in ground effect or when landing. With a down swept tip there is virtually no wingtip vortex in cruise. (The exception would be a very fat Cub.) In slow flight the major vortex is generated in the first ¼ chord of the tip, and is so weak as to not have much effect on anything. This setup does nothing to protect the upper wing low from ambient air pressure outboard of the wing. I tried to build a fence similar to a Crosswinds tip to put on top of a Demer, but ran out of time and went on to other things. If they send me a spare fence I may look into it. Ground effect is where the droop does best. As I stated in an earlier post, the droop tip has less drag at high AOA than at cruise. If the ailerons droop the tip really shines. It’s not hard to imagine the parachute effect of flaps, ailerons, tips all down and in close proximity of the ground. This would be most effective on Takeoff and landing.
There were two posts mentioning the poor stall characteristics of droop equipped aircraft. I can see where that might be a problem if the tips are the only mod on the wing. They would allow the wing to go farther into the stall before it the break occurred. It would be bound to be more pronounced. I would have liked to have seen the addition of Micro V.G.’s to the wing, even if only taped on temporary. My guess is the stall would regain most of it’s composure. Jerry B.
 
Up swept versus Down swept tips.
I had some of these same questions a while back and came up with these answers. If anyone else has done similar research on the matter I would be glad to read it. Opinions excepted.
Ground effect is where the droop does best. As I stated in an earlier post, the droop tip has less drag at high AOA than at cruise. If the ailerons droop the tip really shines. It’s not hard to imagine the parachute effect of flaps, ailerons, tips all down and in close proximity of the ground. This would be most effective on Takeoff and landing.
There were two posts mentioning the poor stall characteristics of droop equipped aircraft. I can see where that might be a problem if the tips are the only mod on the wing. They would allow the wing to go farther into the stall before it the break occurred. It would be bound to be more pronounced. I would have liked to have seen the addition of Micro V.G.’s to the wing, even if only taped on temporary. My guess is the stall would regain most of it’s composure. Jerry B.

Very interesting Jerry, thanks for your analysis and insight. I know my -12 with the Madras, drooped ailerons and VGs in ground effect is very good. However at altitude it won't really stall hard and clean, just porpoise with the rate of sink real high (no break). In this full stalled condition, my ailerons maintain effectiveness, and I can roll wings at will. A simple release of a little back pressure from a full back stick and it is flying. You can kick rudder hard either way and complete cross control it and no roll-over or spin. It is a very safe feeling, and gives you great confidence at or near ground, because it has no bad "bite".
 
Jerry,

Much of your findings/statements agree with my assumptions. My stall on the old plane was not with droop tips, but Hendrickson (sp) tips; the square wing seemed to make the stall so pronounced.

I have always wondered about the vg's on that wing... they had just come out when I was flying that bird. Other unmanageable birds I have seen were tamed with VG's.

But back to the other point, a J-3 is such a nice looking bird with stock bows...
 
Another plus for squared tips (not so much for the J3 for the obvious reasons) is the ability to add length to the ailerons, to the flaps or both.

Scott.....

P.S.= Jerry,,,, Lets watch the fat cub cracks now...............
 
Upper Vortex impeding ambient air pressure from filling in low pressure above wing

Up swept versus Down swept tips.

I had some of these same questions a while back and came up with these answers. If anyone else has done similar research on the matter I would be glad to read it. Opinions excepted.

The upsweep on the jets has a lot to do with the tapered wing and winglet fooling the air into thinking the wing is a lot longer. If the wing were extended to a point it also would be more efficient, but a real pain to taxi around crowded airports. The winglet is a great comprise for a tapered wing. And some winglets do create thrust at cruise speeds. If we reverse a droop like the Demer so it curves up instead of down, it will create a standing vortice above and outboard of the tip. This will have a tendency to contain the low pressure above the wing, which is probably more important than maintaining the high pressure under the wing. It will actually use both pressures to maintain the vortex. This vortex will impede the ambient air outboard of the wing from trying to fill the low pressure above the wing at the expense of losing the somewhat high pressure under the wing. This loss of under wing pressure would be most pronounced in ground effect or when landing. With a down swept tip there is virtually no wingtip vortex in cruise. (The exception would be a very fat Cub.) In slow flight the major vortex is generated in the first ¼ chord of the tip, and is so weak as to not have much effect on anything. This setup does nothing to protect the upper wing low from ambient air pressure outboard of the wing. I tried to build a fence similar to a Crosswinds tip to put on top of a Demer, but ran out of time and went on to other things. If they send me a spare fence I may look into it. Ground effect is where the droop does best. As I stated in an earlier post, the droop tip has less drag at high AOA than at cruise. If the ailerons droop the tip really shines. It’s not hard to imagine the parachute effect of flaps, ailerons, tips all down and in close proximity of the ground. This would be most effective on Takeoff and landing.
There were two posts mentioning the poor stall characteristics of droop equipped aircraft. I can see where that might be a problem if the tips are the only mod on the wing. They would allow the wing to go farther into the stall before it the break occurred. It would be bound to be more pronounced. I would have liked to have seen the addition of Micro V.G.’s to the wing, even if only taped on temporary. My guess is the stall would regain most of it’s composure.

Jerry Burr






I have gone back and read every post Jerry Burr has every posted, several times. Every time another amazing detail is found.

THANKS JERRY !!!!
 
My inexperienced/uneducated take on this:
The top of the wing creates lift by creating a low pressure, compared to the bottom with a high(er) pressure.
Anything that helps to increase the DIFFERENCE in those pressures is gonna help "lift" that wing.
The air moving under the wing tends to slip toward the wingtip... so if you can help to prevent that air easily slipping off the tip, you're increasing the "pressure" under the wing, no? Maybe not much, but bound to help, s'pecially when slow.

As to those who feel their view is blocked, how far do you haft'a move your stick to peek under? Even with a stock wing I like to lift it a bit to peek before I turn that'a way.
My droopy tips were there when I bought the plane, and I remember feeling "that's a good thing". Bird wings are kinked (drooped) from the middle!
And they can turn downwind no prob!
[ducking/running]

My Super Cub had the Madres tips on it when i got it with 32' of wingspan and they are staying on. This thing flys great and lands in crosswinds great. I could'nt ask for it to perform any better. Its fast for a cub, climbs good and wants to start flying around 34 mph and slow flys really well. I had a 150 Cessna with these tips and it was the best performing 150 i have ever flown. As far as blocking vision. You have to lift a wing on all them if you really want to see whats out there.
https://hosting.photobucket.com/images/h468/topwater1956/IMG_4298.JPG
 
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The Madras tips work pretty well on Pawnees. I don’t care for their look on high wing Pipers personally. I like the Hoerner look or classic round wing tip.
 
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