JOL

I've seen some pattern, F3A, F3B planes with a "winglet" on the top of the fuse. What is the purpose of this, or is it just for "show"?

Jetdesign

My Feedback: (8)

Theoretically ('cause I've never used one): It is to correct airflow - straighten it out, or 'clean it up' (make less turbulent) before it hits the rudder. It is for better, more accurate rudder control.

AmericanSpectre505

That is very true Joe,

It releives the turbulence across the vertical and allows it fly in "cleaner air" and provides more of an EXPO feel to the rudder without the EXPO delay., amoung a few other benefits.




bholsten

Rendegade

Just so you know, F3B airplanes are gliders.

apereira

JOL,

It is called "Canalizer", I have been using them for years and they do work very well, they even improve the flying caracteristics of airframes known to be very good already, and the Canalizer improves them even more, many top pilots in the world have adopted them , even when some, knows the advantages but for a matter of pride (to not accept another competitors idea) they don't use it.

Regards

grotto2

My Feedback: (2)

It sounds like something for pattern-mythbusters to confirm or bust.

Maybe someone would be willing to mount a key fob camera on their plane aimed at the empennage that has been covered with tufts of yarn. Then make some video recordings with and without the canalizer.

Jetdesign

My Feedback: (8)

There is not much to confirm. In turbine engines we call them 'inlet guide vanes' - the same principal is used to straighten out or direct air flow before it hits an airfoil (compressor blade or turbine blade). Air sticks to surfaces as they move through it, so a flat plate moving through swirling air will definitely clean up some of the turbulence.

A study could be done to see how effective it is, however I believe guys like Dave L who say they can feel it and that it helps *them with their sequence. I think it would probably do me more harm than good though, at least at this point in my career.

Rendegade

I started flying my wind S without one, and then for a giggle, stuck one on with double sided tape.

The effect was immediate, knife edge was easier, it pulled some of the pitch coupling out, and I reduced my rudder throws as a result.

Now, of course, People like Bryan Hebert will tell you that it's a fix for a flawed design, which I agree with, but it does fix it.

grotto2

My Feedback: (2)

Excuse me if I'm skeptical.

Even if the canalizer works as described, I still don't know a) what to expect when it's added (plus or minus), b) how big it should be, c) what it should be shaped like or d) where it should be placed. Once on my plane, I will be doomed to report that it 'feels' better, lest I admit that I'm a lesser pilot than Mr. Big-Name.

With the technology we have today we still use guess-and-by golly fad approaches for airplane design.

I think we could do better.

serious power

Hi,
All of those questions also apply to the 2nd wing on a bi-plane.
Then that brings a new question ; which is the second wing .
They also apply to the wing of a mono,, .
Do you ,or anyone, have exclusively correct answers to any of these questions.
The F1 guys spend millions ,each, on this stuff and they get new answers almost every time they race.

Brian

AmericanSpectre505

As does NASCAR, NASA, Boeing, N.Grumann,..etc,.................................. ........ Innovation is a wonderful thing. Just put one on my plane and love the benefits!

bholsten

apereira

One thing I do know, is the canalizer works, period, I flew my Osmose with and without it, and flies better with it, rolls better and less rudder input is needed, that is better.

Christophe told me a at Muncie WC he wanted a byplane, and on the Axiome+ he go it, that is why is so big on the +, that thing on being there to correct the design, yes, true on the Oxalys,not anymore on the latest models, but he also says, he does no understand why is it not everybody use it.

Most great pilots designers have adopted it, Silvestri, many Japanesse, etc. My friend Tuny added the Canalizer to his Passport after flying it for a while and the airplane improved greatly.

After being using it in different models, I have my own proof, not need to do any research, it works, but not everybody likes it, and a pretty model is something very important in pattern, pattern planes have its own "magic", and there is a plane for everybody for sure, but you also have to like the way a Canalizer looks.

Regards

Bill Clark

I think he would say its a flawed trim setup not a flawed design.

DaveL322

Ron,

I'm not personally sold on the horizontal component of the Tcan.....depending on the fuse shape and location, a very simple vertical strake can be very effective. The biggest effect is on the pitching behavior in KE. Most modern designs tend to pitch to the belly in KE - unless the CG is quite forward, which causes other trim problems. On every design I've tested a strake or canalizer, adding the device will impart a pitch to the canopy in KE, and the amount of pitch to the canopy is somewhat proportional to the size of the Tcan/strake. I've seen a 1/2" x 6" fin change KE coupling by 3%....very easy way to eliminate Pmix on some planes.

Regards,

grotto2

My Feedback: (2)

Dead-on what I'm getting at, Dave.
If we really had a handle on what's happening here, we may be able to engineer simpler corrective measures, i.e. a number of smaller flow straighteners at critical points.

DaveL322

I don't have a wind tunnel, but at the end of it all, theory is just that, and actual flight results matter the most. I can do a lot of testing cheaply and quickly with nothing more than an exacto, depron, tape, and foam safe CA

Regards,

grotto2

My Feedback: (2)

A wind tunnel's probably out of the question, but I did suggest a cheap alternative to collect quantitative data.

AmericanSpectre505

I was suggesting a wind tunnel would show the actual laminar air flow, lifting areas, bi-lateral separation, pressure areas and turbulence, etc that the T-CAN. can have or induce when attached to an airframe. It certainly will not impede experimental progress through trial and error. Yes, yarn is simple enough, as it gets the job done on sailing sheets on sail boats and other engineering concepts of motion.

Dave does wonderful work and the reason I pick his brain from some years to another.

However, I was just thinking of a larger plexy glass box construction and a large Shulman Electric Ducted fan motor and a colored smoke stick to ignite, perhaps a make shift wind tunnel,..LOL.



Respectfully,

bholsten

Bob Pastorello

My Feedback: (198)

Hi, guys...some of you may remember me, hopefully you'll also remember Nat Penton...Lousiana's "VoodooGuru", who did tweaks to Pattern airplanes a decade or so before some of the 'magical fixes' were invented by big namers. Nat *KNEW* what he was doing, and I flew his .90 powered Voodoo with a canopy strake/fin like Dave L. describes when I was in FAI. It was - hands down - the very best knife edge-ing plane that I flew, EVER, and his rudder area was reduced as well as it's travels.

Scientific design would be a wonderful thing, but we have such great experienced and knowledgeable "tweakers" out there that it's really great.

I don't play pattern anymore, but I do have a couple of "good" planes (which means they fly better now than I ever did) and I enjoy precision. I just wanted to give Nat the recognition for many of his innovations. If I remember correctly, he was also the first to "prove" that pattern planes without airfoil landing gear and pants "flew better"....he and DIck Hanson(way back, now) knew the value and practical benefit of performance over pretty....God bless 'em!!!!!!!!

serious power

Hi Dave,
I don't doubt ,at all, what you say or have found.
With that said I will add the following;
It was CPLR that brought the the T Can,, to this party.
He has removed the vertical component and now sits the 'winglet' directly on top of the fuz,, .
I'm assuming he finds it as good or maybe even better.

All I am saying is that there is ,so far anyway, no one size fits all solution but there are clearly benefits to these 'winglets'.

Brian

RC_Pattern_Flyer

My Feedback: (1)

Nat Penton had fins years before CPLR.

Mark Hunt continued this with the original Pentathlon and carried it through the evo.

Chuck Hochhalter

apereira

I think this comes from the same idea, Mr. Penton was a great innovator. This one from Germany, just flew at the Liechtenstein Open.

Bob Pastorello

My Feedback: (198)

You know, those are cool-enough looking that even if they didn't work, it would be worth doing just for conversation's sake....very neat...

serious power

Hi,
I said T Cann,, ,as in winglet, not 'fin' .

Brian

RC_Pattern_Flyer

My Feedback: (1)

Yes sir, my apologies.

Geoffrey Lumay just completed a composite version of the Voodoo express in Belgium, beautiful plane.

Chuck