Don't forget that the winglets are mounted (and add to) the washout in the wing--hence requiring adding (nose up) to the angle of attack giving more drag (ice?) for level flight. 

 

Charlie K.

 

See me on the web at

www.Lancair-IV.com

 

---

From: Colyn Case <colyncase@earthlink.net>
To: lml@lancaironline.net
Sent: Wednesday, June 8, 2011 8:25 AM
Subject: [LML] Re: Winglets? And introducing myself as a very near future 4p owner.

there are two questions: stability and speed.

if you go into the archives you will find comments about both.

My favorite on the speed is in the series of drag reduction articles by Fred Moreno:

http://lancair.net/archives/Drag_Reduction_Part_1.pdf

search the doc for "winglets" and find "side note on winglets"

I don't know what the full argument for stability comes down to aerodynamically.

....is it simply the added span?

I can say that the roll input required with winglets is unpleasant at high speeds.

careful on the buy.   the airframe could be perfect but still lots of gremlins in the systems.

Colyn

On Jun 7, 2011, at 2:18 PM, RONALD STEVENS wrote:

Hello guys.

I like to introduce myself, I am 50, European/American, former Cirrus

SR22 (1100 hours) and Velocity TXL5 (250 hours, just sold this plane)

(total 1400 hours).

I am a future Lancair 4p owner (looking to buy one these weeks, so if

you know someone who wants to sell his let me know) and looked at a few

Lancair 4p already.

Now about the winglets (my first question);

Some planes I looked at had their winglets, some not. All those that did not had one told me it doesn't do anything, the ones they had did told me it works great,

more stability etc, even the CAFE report is telling that it produces

more stability at higher altitude.

But…even the big Charlie Kohler told me it doesn't add anything but more

drag...thus less speed.

I have no experience whatsoever with the Winglets. So my question to you

guys is, do you have any experience telling you that it does work? (this

is more for pilots who had both so they can tell the difference)

Thanks -- Ronald Stevens