First, hello to everyone and thank you for all the wonderful information and insights on the forum. Sure is fun to read and learn from others experience.
A question that maybe some of you have opinions on.
I am building a Bushcaddy 4 place bush plane and nearing completion ever so slowly. We are not happy with the poor excuse for workmanship on the stock wingtips sent with the kit. I am looking to gather information and design tips for making a mold and glassing up our own droop wing tips.

I have seen dimensions of the different cessna options and they are all too short in the cord.
Any things to consider to make an effective shape?

Thanks for the input!!

Cam

Remember that you have high press. under the wing, & low press. above. Try to negate the tendancy for those pressures to equalize. (vortex). Straight (slab) tips will give more speed (less drag) than droopies.
LOTS of talk about tips here & on SCub.org. Do searches!

I am certainly no expert, but I've done some reading, and the common conjecture seems to be that drooped wingtips designed well are scarsely better (too small to measure) than regular wing tips (but look SERIOUSLY cool...), and drooped wingtips designed poorly only create extra drag and offer no benefits compared to regular tips (but still look cool).

I think I read that they were popularised by Cessna (210?). Apparently after the flight testing had proved they didn't offer the benefits the engineers had hoped for, a marketing guy happened to see them on the plane, and talked the bosses into leaving them on because it would help sales... and forever after people have been searching for good reasons to install them!
I can probably dig up the article.

Here it is (page labelled -7- near the back, pages aren't in order...)
https://dl-web.dropbox.com/get/Public/Speech%20Presented%20at%20Boise%20Skywagon%20Club%20meeting%201979.pdf?w=195760b9

The clever test he describes is to fly the plane with one drooped tip and one normal tip installed, without altering the rigging. Apparently they found the drooped tips don't produce any extra lift whatsoever, and the plane flew dead level. Drag maybe? Yet they still look awesome.

I am installing Hoerner type tips when I pull my wings to put in larger fuel tanks in a week or so. They seem to work, at least I've never heard them dissed real bad... but mostly they look cool, don't block viz like droops, don't hurt obstacle clearance, and I know a guy making them for my type plane.

Plus my factory supplied ones (non hoerner, non droop, more just cosmetic to pretty up the end of the) are trashed, some one keeps sneaking into my hangar at night and working them over.

Have a look at the modern light transport designs from Dornier. Have a look at the Discus sailplane, and the later versions of the Ventus sailplane. Have a look at hawks and eagles and falcons. For that matter have a look at any recent competition R/C model glider. All different airfoils, speeds, sizes, weights, Reynolds numbers, and surface finishes,but they all tell the same story when viewed from above. Sharply swept leading edge, straight or mildly aft-swept trailing edge.

courierguy wrote:I am installing Hoerner type tips when I pull my wings to put in larger fuel tanks in a week or so. They seem to work, at least I've never heard them dissed real bad... but mostly they look cool, don't block viz like droops, don't hurt obstacle clearance, and I know a guy making them for my type plane.

Plus my factory supplied ones (non hoerner, non droop, more just cosmetic to pretty up the end of the) are trashed, some one keeps sneaking into my hangar at night and working them over.

Got a photo?

Even though they don't provide lift your wing will have to be capped somehow and the small droop does look good on a square tipped wing. It is a simple way to end the wing with very small loss of visibility.

Battson wrote:

courierguy wrote:I am installing Hoerner type tips when I pull my wings to put in larger fuel tanks in a week or so. They seem to work, at least I've never heard them dissed real bad... but mostly they look cool, don't block viz like droops, don't hurt obstacle clearance, and I know a guy making them for my type plane.

Plus my factory supplied ones (non hoerner, non droop, more just cosmetic to pretty up the end of the) are trashed, some one keeps sneaking into my hangar at night and working them over.

Got a photo?

Not that I can find right off, I'll opost when I get them on, plus any difference if any in performance.

Or did you mean pictures of my boogered up ones? Ain't pretty......

Thank you very much for the replies. I have searched extensively on Supercub.org and have a good idea of the shape that I'm looking for. If anyone has pictures of different droop shapes that would be really cool.
Thanks again, fantastic group here.
Cam

These are some shots of my Tundra. Only a little droop but it works well with the deep chord wing in my opinion. Don't know the Bushcaddy airfoil this is a modified Riblett 660.15.

http://www.backcountrypilot.org/gallery ... pos=-16931
http://www.backcountrypilot.org/gallery ... =776&pos=1
http://www.backcountrypilot.org/gallery ... =776&pos=2
http://www.backcountrypilot.org/gallery ... =776&pos=3

I can get one of just the wing tip and measure it tomorrow if you think this is what you like.

Dirtstrip,

That is a beautiful plane of yours. You did a great job putting that together. I was looking at a full page view of the photo of your Tundra on the grass, it looks like an alien is looking out the window at us. You're not carrying any extra passengers are you?

How do you like your steps over the tires? That looks like a neat feature.

Not steps. I made the fenders so I could fly off my test hours without wrecking my prop which was getting hit by mud slung up from the tires on the dirt road. The snow had melted and the fields and roads were still wet and in two weeks I would be planting. They are one offs. I don't have them on anymore but they are still hanging here. The photo on the grass with the tent has a reflective fold out sunscreen in the windshield. The alien is taking the picture.

Whoa there, I just zoomed in for the big one on the side window. Blackrock, the giant fuzzy dice do look like an alien.

I have Madras really droopy tips on LRB--they were on her when I bought her, and I agree they look cool. They also add drag--how much, I don't know exactly, but I'd guess they slow my cruise down maybe 4 or 5 knots from stock Cessna tips. They also block vision straight out the side. However, they definitely add to slow speed control, as near the stall the ailerons have much more authority than a stock Cessna's ailerons. And they look cool.



Cary

dirtstrip wrote:These are some shots of my Tundra. Only a little droop but it works well with the deep chord wing in my opinion. Don't know the Bushcaddy airfoil this is a modified Riblett 660.15.

http://www.backcountrypilot.org/gallery ... pos=-16931
http://www.backcountrypilot.org/gallery ... =776&pos=1
http://www.backcountrypilot.org/gallery ... =776&pos=2
http://www.backcountrypilot.org/gallery ... =776&pos=3

I can get one of just the wing tip and measure it tomorrow if you think this is what you like.

I can't get enough of that plane. It is so good to look at!
Those are nice tips, I would like a set like that for the Bearhawk for sure.

Back in mid 1990's when Ace Deamers (Madras ,Ore.) died I contacted his son(s) and tried to buy the entire STC- paperwork and company. I had a pair on my 182 and they WORKED extremely well. I call them the cheapest >most cost effective STOL mod. Biggest hang up was(is) deep droop and head clearance in hanger. Flew with the old Ace Deamers Super Tips for about 2-3 years -have had another dozen or so pairs since and sold them .

I had to repair one of my small droop wing tips. This is the right wing tip and we normally load the rt wing with fuel and just keep a reserve on the left so the plane flies rt wing heavy and control pressure is required to keep the wing up. After the repair the heavy wing was gone and more right rudder was required. Now I have to repair the left tip reducing the drag without the added lift.

I have been working with a friend to design a droop tip for our plane. The airfoil is a naca 4412 with a 63 inch cord. Thank you to everyone on here who has had input on this thread. It has been a big help. With a little more tweaking, I think I will get to the shape I want.
Cheers
Cam

Are these for aesthetics or performance? I have yet to tuft and video the tips that I use with repairs. All that work goes into the shape for airflow and then the nav / strobe light is installed longitudinally . I just started working on a kit for wingtip landing lights. Removing the superdroops and wing x on the turbine 206 now that initial shake down is done. Plenty of climb performance and I still get good slow speed with the Sportsman.

I understand droop tips have limited benefit if any compared to a hoerner tip, so I can't say this is strictly for performance. The fact is the original tips with the kit are junk and I need to make something. Aesthetically, yes I think they look cool and I am impressed with similar tips on droop tips on similar planes.
I plan on increasing the radius and kicking out the droop edge so that the airflows straight back along the curved surface.
I hope to submit the finished design soon.
cam

Water streaks on my 206s with superdroops and wing x near the tip show little span wise flow on the bottom of the wing. <3 inches from the trailing edge the streak turns < 1/2 inch outboard. Span wise flow begins on my swept wing longeze at 6 inches from the trailing edge and moves outboard 3inches. (inboard of the winglet a few feet) I will try and install a Cessna standard droop on one side and leave the otherside in superdroop. Tuft and stalls. It is in experimental by the way!!