lml@lancaironline.net Mailing List Archive

Another comment on winglets.

My theory is the most important speed is your SL speed.

Suppose you are flying 1350 nautical miles.

Westbound you have a 40 knot headwind at 5000 increasing to 100 knots at fl200.

Eastbound let's say you get a 40 knot tailwind at fl200. (Doesn't it usually work out that way?)

Someone offers you mod A that gives you 10 knots at 5000 or mod B that gives you 10 knots at fl200.

...and let's say your plane does 225 knots at 5000 unmodified.

mod A gives you 10/(225-40) or 5.4% improvement which you enjoy for 6.9 hours

mod B gives you 10/(270+40) or 3.2% improvement which you enjoy for 4.2 hours

So even if the winglets delivered performance up high they don't seem like a very good deal.

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

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