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  #11  
Old 10-03-2014, 01:53 PM
David Paule David Paule is offline
 
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A really good book is Hoerner's "Fluid Dynamic Drag." Still available, I think. It's the book Mike Arnold studied.

If I understand the concept (and I might not) when you add the fairing, you increase the wetted area, and thus the parasitic drag. If the decrease in intersection drag isn't at least that much, you haven't helped.

I think that the idea is to gradually increase the radius starting small near the front and getting bigger near the rear. How much or how little, I don't know. And how to orient the aft end of the fairing as it transitions to the fuselage, another mystery.

Dave
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  #12  
Old 10-03-2014, 04:57 PM
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Jesse Jesse is offline
 
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In at least 2 planes that were flying without them then added them, one gained 3-4 kts in cruise and the stall speed dropped 3 kts. In the other his testing showed 4-5 kts in cruise increase. He didn't compare his stall speeds. They were designed by an aeronautical engineer and they do work.
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  #13  
Old 10-03-2014, 06:01 PM
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woodmanrog woodmanrog is offline
 
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I had fairings like these on my first plane. On advice from two of the best builders I removed them and gained 8 knots ground speed. As I was told, if you want to go fast, look at fast airplanes. Fighter jets have no fairings because there is no or little dihedral.
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  #14  
Old 11-12-2015, 05:17 PM
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Jesse Jesse is offline
 
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I know this is an old thread and I should probably just start a new one, but I want people to know the contrary views when looking at this, even though testin has shown a speed improvement. As I mentioned in my previous post, these were designed by an aeronautical engineer and they have shown a speed improvement on all installations.

We installed a set of fairings today and should have some independent speed results in the next week or so.

Attached are pictures of the new installation. We have these in stock and are offering them now for $2,000 installed (installation options vary, but his would be the lower cost option included in this price). We can install them in an afternoon. Of course, paint is not included, but the fairings are filled and primed, so a tiny bit of prep will get them ready for paint. No pinholes. The added weight should be about 6 lbs, again, depending on the installation format.







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Last edited by Jesse : 11-12-2015 at 05:22 PM.
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  #15  
Old 11-12-2015, 06:26 PM
rocketman1988 rocketman1988 is offline
 
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Default Do you have to install them?

Jesse, do you have to install them or are they available as a "kit"?

Bob
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  #16  
Old 11-12-2015, 06:32 PM
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Jesse Jesse is offline
 
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They are available as a kit. Pricing would depend on your desired attach method, but they install quickly, so there would not be a big discount of shipped. If you pick them up we can offer a little better price.
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  #17  
Old 11-12-2015, 06:41 PM
rocketman1988 rocketman1988 is offline
 
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Default What are the attach methods?

What are the different attach methods?

Bob
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  #18  
Old 11-12-2015, 06:48 PM
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Jesse Jesse is offline
 
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Along the inboard end of the wing it's pretty much just the same screws as would hold the standard fairing. Along the fuse side skins the options are rivets (fastest), rivnuts (relatively fast, but the possibility of the rivnut spinning) or nutplates (the best method if easy removal is desired, but much more work to get all of the nutplates installed). Then you can choose the size of the rivets or screws. You also need to decide the spacing of the fasteners.

The rivet method works really well and inspection of the wing root can be done from the bottom, so it would not be necessary to remove them unless perhaps in the case of n ding to remove a fuel tank or the whole wing. The rivets would then need to be drilled out. In our installation today we used CS4-4 rivets and the normal #8 screws on the wing.
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  #19  
Old 11-13-2015, 10:23 AM
Selma Selma is offline
 
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Default RV9

Jesse,
Did you ever consider to install these fairings on a RV9 ?
How much weight do they add to the plane?

Thanks Pit
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  #20  
Old 11-13-2015, 06:17 PM
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majuro15 majuro15 is offline
 
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I think these are a great product! Glad to see more folks are putting them on after flying without first. Hopefully get some more data from them. They give it a great look as well.
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