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savannah174(at)msn.com
Guest

Posted: Tue Dec 12, 2006 4:23 am Post subject: vg's

Yes there is a bad thing about the VG's and that would be having to wait 10 

days for the mail shipment to arrive, sorry that's all I can think of at the 

moment

RJ

---

zodierocket(at)hsfx.ca
Guest

Posted: Tue Dec 12, 2006 5:38 am Post subject: vg's

OK, will do! It doesn't matter if the plane fly's better with the slats

or without. But in America and Canada lets just see how fast the

insurance companies bail on your ass for removing a flying surface that

the designer says should be there. Regardless of any situation that may

involve the NTSB removal of the slats called forth by the designer would

be written in as a contributing factor( likely even if you ran out of

gas), in which the builder removed before flight and once again have fun

with AVEMCO or any other insurance dealer. Also since you have

experimented and removed the slats the designer called for then you have

made a structural change and can no longer call it a 701, once again

enjoy your insurance company when you tell them this is a one off. If

you're Canadian, I doubt your 701 would pass an inspection for the MD-RA

to get it's flight authority and if you register as an AULA you are not

allowed to remove anything from the plans. 



I can't comment on the pro's of VG's, I know a lot of people have made

money selling them. I also know that until the designer states that the

design requires VG's they will never see my plane.



As for reported testing having been done. I don't dispute there figures

but I do caution most to consider this. I have a 701 close to me that

cruises at 85mph, and another with the same engine that cruises at 105

at the same power setting. Difference is that the builder of the second

701 streamlined the struts, cleaned up the cowling, adjusted so that the

stabilizer is on correctly with flight checks. There were no major

modifications just common sense clean up and he is cruising his 701 at 5

MPH below the Vne! The Recreational Flyer magazine article that shows

this comparison is on the Zenith website.



Personal outlook only. You can add whatever you want to your 701, remove

what you want from your 701, and believe in anything you want! But I

will not be removing my slats! I do not plan on cruising ANY plane at or

near Vne. I'm quite happy with a 701 that can cruise at 95mph with a

Rotax 912S I believe that this is well within reach of anyone who has

built a straight 701 and will now spend the time to clean it up. You

want an instant 5mph in your 701? Call Zenith and order the new FWF. As

a bonus your fuselage will be quieter from the less vibration passed on

by the new engine mount. Another 5mph can be gained by taking a piece of

.016 and wrapping your struts into a streamline airfoil. I'm not going

to risk an insurance company telling me that I don't have coverage after

I hit a deer on the runway when the NTSB states that I have removed a

portion of flying surface! 



You folks that have gone through all the hassle of removing the slats

and adding Vg's good for you, your courage deserves applause. But when

it comes to the 701 if the owner is not getting over 75mph cruise with a

912, then they need to spend time fixing what they have wrong, not throw

parts away! ( well maybe the prop) For those who have a 701 flying at

100mph cruise or higher, why would you want to be that close to Vne all

the time? 



Mark Townsend  Alma, Ontario

Zodiac 601XL C-GOXL, CH701 just started

www.ch601.org / www.ch701.com / www.Osprey2.com

--

dougsnash(at)yahoo.com
Guest

Posted: Tue Dec 12, 2006 5:42 am Post subject: vg's

Firstly, let me say that this VG instead of slats is

an interesting idea, sounds like some good results.  A

little careful experimentation is not a bad thing.   

That being said, I don't think I'll be going that way

myself.  I'll probably stick with the slats.



Now for my personal "nay sayer" reasoning.  The point

that several of the posters have made here that

apparently is not being acknowledged is: According the

Chris Heintz, the slat is NOT an add on component to

maximize the angle of lift.  The shape of the slat is

actually part of the designed airfoil.  The shape of

the wing minus the slat is a totally different airfoil

than what Chris chose when he designed the CH-701.



The fact that this different airfoil works as well as

it is reported too has convinced me of just how

exceptional VGs really are in controlling separation

of the boundary layer.  That and a testament to how

well the CH-701 is designed that you can make a major

change like removing the slats and adding VGs and

still get excellent STOL performance.



Another interesting test might be to maintain Chris'

chosen airfoil by blocking off the gap (as has been

suggested) and trying VGs.  I would be very interested

in the results of that trial.  I personally would

prefer to go this route if I was going to eliminate

the slats.



For those posters who have tried the slat elimination,

keep letting us in on your test flying results, it

sounds like you are getting some good ones.



do not archive



Doug MacDonald

CH-701 Scratch Builder

NW Ontario, Canada



 

Have a burning question?  

Go to www.Answers.yahoo.com and get answers from real people who know.

n801bh(at)netzero.com
Guest

Posted: Tue Dec 12, 2006 6:47 am Post subject: vg's

With 1700 hours of testing you surely have at least ONE picture of a 701 actually flying in the air with the slats removed. 

 I am still waiting to see it. !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 

do not archive

Ben Haas

N801BH

www.haaspowerair.com



-- "secatur" <appraise1(at)bigpond.com> wrote:

--> Zenith-List message posted by: "secatur" <appraise1(at)bigpond.com>



Well, I guess I'll just have to change my mind and build the slats and throw these VG's away !

1700+ hours of independant, documented testing WITHOUT 1 negative report ain't gonna convince me!

And when my 701 is finished I will park it right next to my Wright Flyer, and my Model T ford (Black of course!) right under the big sign that says "EXPERIMENTAL..do not change or alter ever...or else!!"



ps: Can somebody please post some BAD results with VG's instead of Slats .... so I can feel justified??



Wowie Zowie !





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=================================================nbsp;Please Support Your Lists This Month nbsp;the Contribution link below to find onbsp;    * Aeroware Enterprises www.k=                              -Matt Dralle, List&nbsp========================         - The Zeatronics List Features Navigator to browse

_-= the many List utilities such as sp;  --> http://www.matronics.com/Navigator?Zenith-Lis======================================

   [quote][b]

n801bh(at)netzero.com
Guest

Posted: Tue Dec 12, 2006 6:53 am Post subject: vg's

Can I have an AMEN .................................. 

do not archive

Ben Haas

N801BH

www.haaspowerair.com



-- "ZodieRocket" <zodierocket(at)hsfx.ca> wrote:

--> Zenith-List message posted by: "ZodieRocket" <zodierocket(at)hsfx.ca>

OK, will do! It doesn't matter if the plane fly's better with the slats

or without. But in America and Canada lets just see how fast the

insurance companies bail on your ass for removing a flying surface that

the designer says should be there. Regardless of any situation that may

involve the NTSB removal of the slats called forth by the designer would

be written in as a contributing factor( likely even if you ran out of

gas), in which the builder removed before flight and once again have fun

with AVEMCO or any other insurance dealer. Also since you have

experimented and removed the slats the designer called for then you have

made a structural change and can no longer call it a 701, once again

enjoy your insurance company when you tell them this is a one off. If

you're Canadian, I doubt your 701 would pass an inspection for the MD-RA

to get it's flight authority and if you register as an AULA you are not

allowed to remove anything from the plans. 



I can't comment on the pro's of VG's, I know a lot of people have made

money selling them. I also know that until the designer states that the

design requires VG's they will never see my plane.



As for reported testing having been done. I don't dispute there figures

but I do caution most to consider this. I have a 701 close to me that

cruises at 85mph, and another with the same engine that cruises at 105

at the same power setting. Difference is that the builder of the second

701 streamlined the struts, cleaned up the cowling, adjusted so that the

stabilizer is on correctly with flight checks. There were no major

modifications just common sense clean up and he is cruising his 701 at 5

MPH below the Vne! The Recreational Flyer magazine article that shows

this comparison is on the Zenith website.



Personal outlook only. You can add whatever you want to your 701, remove

what you want from your 701, and believe in anything you want! But I

will not be removing my slats! I do not plan on cruising ANY plane at or

near Vne. I'm quite happy with a 701 that can cruise at 95mph with a

Rotax 912S I believe that this is well within reach of anyone who has

built a straight 701 and will now spend the time to clean it up. You

want an instant 5mph in your 701? Call Zenith and order the new FWF. As

a bonus your fuselage will be quieter from the less vibration passed on

by the new engine mount. Another 5mph can be gained by taking a piece of

.016 and wrapping your struts into a streamline airfoil. I'm not going

to risk an insurance company telling me that I don't have coverage after

I hit a deer on the runway when the NTSB states that I have removed a

portion of flying surface! 



You folks that have gone through all the hassle of removing the slats

and adding Vg's good for you, your courage deserves applause. But when

it comes to the 701 if the owner is not getting over 75mph cruise with a

912, then they need to spend time fixing what they have wrong, not throw

parts away! ( well maybe the prop) For those who have a 701 flying at

100mph cruise or higher, why would you want to be that close to Vne all

the time? 



Mark Townsend  Alma, Ontario

Zodiac 601XL C-GOXL, CH701 just started

www.ch601.org / www.ch701.com / www.Osprey2.com

--

stutzman(at)stutzman.com
Guest

Posted: Tue Dec 12, 2006 9:03 am Post subject: vg's

OK, let me preface this by saying that I am not a 701 builder (yet) nor

have I even flown one.  I have however owned, flown and insured several

experimental aircraft, including one which was a 'one of a kind'



On Tue, 12 Dec 2006, ZodieRocket wrote:



 	  Quote: 	
		   



 But in America and Canada lets just see how fast the

 insurance companies bail on your ass for removing a flying surface that

 the designer says should be there.


	


Has anyone attempted this conversation with their insurance company?  I

doubt the insurance companies would even blink (well, ok, they might use

it as an excuse to squeeze you for a higher premium).



Every experimental plane is differnt as far as the insurance compaines are

concerned.  Just consider the variations in engine installations and fuel

systems that we have talked about here on this list.  Are the folks who

are installing the corvair, subaru, or harley-davidson engines in their

planes having problems getting insurance?  They may get stuck with higher

premiums, but I wager they CAN get insurance.

 	  Quote: 	
		   For those who have a 701 flying at 100mph cruise or higher, why would

 you want to be that close to Vne all the time?


	


Just because you can cruise at that close to Vne doesn't mean you have to.

Cleaning up a plane such that 100mph cruise is possible has all sorts of

benefits, the most obvious of which is a much more effecient fuel burn at,

say, 85 mph.



I'm a loooong way from having to think about making this slat/vg decision.

Its just that I don't buy many of the arguements made here.  The most

compelling arguement I've seen here is the one person who mentioned the

potential reduction in structural strength of the wing by the removal of

the slats.  Thats a topic I'd like to see the VG proponets address.



Frank Stutzman

Bonanza N494B     "Hula Girl"

Hood River, OR

JohnDRead(at)aol.com
Guest

Posted: Tue Dec 12, 2006 11:03 am Post subject: vg's

How about flush riveting a 701 that should make it exceed Vne easily?

  

 This is such fun!

  

 John Read

 CH701 in Colorado

  [quote][b]

billmileski

Joined: 07 Aug 2006
Posts: 68
Location: Ledyard, CT

Posted: Tue Dec 12, 2006 11:10 am Post subject: Re: vg's

Reading all this, I can't help shaking my head, and conclude a few things.



This month in Sport Pilot (or Sport Aviation), a perfect example.  A compelling article about the KR community -- led by a wonderful guy who has transformed the plane over time, through innovation supported by definitive testing.  The article discusses the phenomenon of hand-wavers versus those who want to really find out, through objective testing.  Long winded theory about what would happen in a low altitude engine-out landing was replaced by a test with data gathering.



This list sounds to me like people who want a turn-key airplane, and speak mostly of what expensive avionics they plan to put in their panels. With some very notable exceptions, of course. However, it's funny how people on this list will cry foul and expound their great knowledge of aerodynamic theory, as soon as someone wants to breach the topic of experimenting. Ironic, because those so eager to speak theory seemingly have no interest in experiencing it first hand.  And there is a lot of misinformation in the midst.



In almost every post, there is evidence that the poster hasn't read this from the beginning, or read the other web sites, and is lacking some pertinent knowledge (e.g. "the slat is part of the airfoil, we should try blocking the gaps and see what happens" -- experimental results are available on exactly this test, and also stability, but no one bothered to read far enough).



So we are left with a community of builders largely sticking to the stock parts, and heralding the designer as a god who should not be questioned.  That's fine, but some people are still experimenters, and they should not be crucified, just because they are vulnerable, once they open the topic of modifying CH's designs.  Guess what, all complicated mechanical systems are a work in progress (take a look at the 912 service bulletin history). I have heard people say that Chris Heintz always thought that the 80hp 912 was overkill for the 701, but we don't feel bad about strapping 100hp on this airframe now, do we, since we are comfortable with the success of this market-pressured upgrade.



Crying about insurance seems silly, none of our planes are a bargain to begin with, and supposedly there is some liability risk after sale of the aircraft, and god knows depreciation hits us harder than the certified crowd.  If you want to cry that loud, go ask your insurance company and report us the results, and help add actual information (and quality) to this list.



Those who react nearly violently to the notion of experimenting with the design, sound like they are feeling threatened, and are looking for support to validate their own choices. We are all free to make the choices that we are comfortable with, it's just a shame that sometimes this list sounds like a gradeschool yard, with people forming little packs to help make themselves feel better.



Now where do I stand on the slat issue (if you care)?  I think any modification that reduces drag on the airframe at my desired cruise speed (85mph is fine with me), is reducing strain on the airframe, and that seems like a good thing.  It sounds like efficiency gain includes a better climb rate, and improved glide, which seem nice.  If you're worried about Vne, just enjoy the extra economy at smart cruise speeds, and by the way you could have exceeded Vne by pushing the stick forward before, and you chose not to do so.  I wonder if landing distance is increased at all, since speed may not bleed quite as quickly in the flare, and if there is a net loss of strength in the wing structure.  However, I don't know if I will remove my slats ever, I enjoy the aircraft, with its pluses and minuses.  It definitely has a personality, and it would likely have a different one with VGs instead.  I kind of like the appearance too.  I feel like I ought to try it, though, in the spirit of experimenting, which is what the EAA was founded upon.



In sum, it would be terrific if we could quantify with actual data, or at least a classic test flight approach like CAFE, how the whole package behaves in the VG/no slat configuration.  And it would be great if Chris Heintz would comment on the structural (and other) issues. And it would be great if we all tried to keep this list friendly, and based on a sharing of knowledge, without fear of posting questions, or trying new things.



All the best,



Bill Mileski

701 65hrs

milreed(at)directcon.net
Guest

Posted: Tue Dec 12, 2006 11:48 am Post subject: vg's

Hi 

 Want to thank John, and Joe and Joan for the feed  back. My intent is to build exactly to the plans of the CH 701. Was reading  "C.H. Design College" and found very interesting. The differences in opinion is  what science is all about. Will see how this plays out with the data. Please  send more empirical information.

 Mil 

    

    [quote][b]

Flydog1966(at)aol.com
Guest

Posted: Tue Dec 12, 2006 2:41 pm Post subject: vg's

In a message dated 12/12/2006 2:14:09 P.M. Eastern Standard Time,  mileski(at)sonalysts.com writes:

  	  Quote: 	
		  

This    month in Sport Pilot (or Sport Aviation), a perfect example.  A    compelling article about the KR community -- led by a wonderful guy who has    transformed the plane over time, through innovation supported by definitive    testing.  The article discusses the phenomenon of hand-wavers versus    those who want to really find out, through objective testing.  Long    winded theory about what would happen in a low altitude engine-out landing was    replaced by a test with data gathering.



This list sounds to me like    people who want a turn-key airplane, and speak mostly of what expensive    avionics they plan to put in their panels. With some very notable exceptions,    of course. However, it's funny how people on this list will cry foul and    expound their great knowledge of aerodynamic theory, as soon as someone wants    to breach the topic of experimenting. Ironic, because those so eager to speak    theory seemingly have no interest in experiencing it first hand.  And    there is a lot of misinformation in the midst.



In almost every post,    there is evidence that the poster hasn't read this from the beginning, or read    the other web sites, and is lacking some pertinent knowledge (e.g. "the slat    is part of the airfoil, we should try blocking the gaps and see what happens"    -- experimental results are available on exactly this test, and also    stability, but no one bothered to read far enough).



So we are left with    a community of builders largely sticking to the stock parts, and heralding the    designer as a god who should not be questioned.  That's fine, but some    people are still experimenters, and they should not be crucified, just because    they are vulnerable, once they open the topic of modifying CH's designs.     Guess what, all complicated mechanical systems are a work in progress (take a    look at the 912 service bulletin history). I have heard people say that Chris    Heintz always thought that the 80hp 912 was overkill for the 701, but we don't    feel bad about strapping 100hp on this airframe now, do we, since we are    comfortable with the success of this market-pressured upgrade.



Crying    about insurance seems silly, none of our planes are a bargain to begin with,    and supposedly there is some liability risk after sale of the aircraft, and    god knows depreciation hits us harder than the certified crowd.  If you    want to cry that loud, go ask your insurance company and report us the    results, and help add actual information (and quality) to this    list.



Those who react nearly violently to the notion of experimenting    with the design, sound like they are feeling threatened, and are looking for    support to validate their own choices. We are all free to make the choices    that we are comfortable with, it's just a shame that sometimes this list    sounds like a gradeschool yard, with people forming little packs to help make    themselves feel better.



Now where do I stand on the slat issue (if you    care)?  I think any modification that reduces drag on the airframe at my    desired cruise speed (85mph is fine with me), is reducing strain on the    airframe, and that seems like a good thing.  It sounds like efficiency    gain includes a better climb rate, and improved glide, which seem nice.     If you're worried about Vne, just enjoy the extra economy at smart cruise    speeds, and by the way you could have exceeded Vne by pushing the stick    forward before, and you chose not to do so.  I wonder if landing distance    is increased at all, since speed may not bleed quite as quickly in the flare,    and if there is a net loss of strength in the wing structure.  However, I    don't know if I will remove my slats ever, I enjoy the aircraft, with its    pluses and minuses.  It definitely has a personality, and it would likely    have a different one with VGs instead.  I kind of like the appearance    too.  I feel like I ought to try it, though, in the spirit of    e!

xperimenting, which is what the EAA was founded upon.



In sum, it    would be terrific if we could quantify with actual data, or at least a classic    test flight approach like CAFE, how the whole package behaves in the VG/no    slat configuration.  And it would be great if Chris Heintz would comment    on the structural (and other) issues. And it would be great if we all tried to    keep this list friendly, and based on a sharing of knowledge, without fear of    posting questions, or trying new things.



All the best,



Bill    Mileski

701 65hrs

	


 

        Bill. Well said !

       do not archive

       flydog

       701

       

  [quote][b]

Avidmagnum

Joined: 18 Nov 2006
Posts: 19
Location: Wisconsin, Florida

Posted: Tue Dec 12, 2006 4:10 pm Post subject: Re: vg's

Hi Les

I will only sell my slat's to someone who wants to pick them up local. Too much trouble to wrap and ship.  So it would have to be Florida or Wisconsin as I spend time in both locations.  Have fun with your 701 it's going to be a great aircraft.    Life is short......FLY!      Tom

Float Flyr

Joined: 19 Jul 2006
Posts: 2704
Location: Campbellton, Newfoundland

Posted: Tue Dec 12, 2006 5:29 pm Post subject: vg's

Mark:  

 I don’t' think you would have problems removing the slats to get the plane passed the MD-RA  I've seen greater design changes made to aircraft that passed.  Remember the paper work on W&B needs to reflect the airplane without the slats.  The configuration is almost considered normal in other countries with no known problems and some of those countries have a relatively similar level of legislation controlling aircraft authority for flight.  Now if the 701's with the slats off were falling like flies in the Raid factory you would no doubt have problems.    

You are dead right on one point and that has to do with anyone wanting to register their plane AULA.  No changes from the letter of conformity are allowed.  If the plans call for a placard against chewing gum it better be there.  I'll bet you are right on the insurance issue of calling it a CH701 too but there wouldn't be anything wrong with a JD701 (John Doe 701)  

On the use of VGs These little devices are used on all kinds of certified aircraft.  Their placement is usually determined by wind tunnel testing.  Their effectiveness when properly installed is proven.  The operative words are, "properly installed".  Considering that no one here will be hitting mach 1 I would think that if someone installed the VGs and did the appropriate envelope testing at altitude their use should be safe… A word of caution, the handy man's secret weapon will probably shoot down your plane.  

My question still stands:  the CH701 is noted for poor glide ratio… does removing the slats improve the glide ratio.    

Noel  

 

  

[quote] --

_________________
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats

ggower_99(at)yahoo.com
Guest

Posted: Wed Dec 13, 2006 12:26 am Post subject: VG's

Probably yes, Bob.    But for me,  playing around with airfoils in wings is more for a Professional Test Pilot wearing a parachute    that  for me...



Saludos

Gary Gower.



NYTerminat(at)aol.com wrote:[quote]      Gary,

  

 There is always room for improvement. If the vg's give you the same stol  performance and allows you to go faster and uses less fuel, I don't see too many  downsides.

  

 Bob Spudis

  

 N701ZX  CH701/912S 92hrs

  

  

  

 In a message dated 12/11/2006 1:02:07  [quote][b]

ggower_99(at)yahoo.com
Guest

Posted: Wed Dec 13, 2006 11:30 am Post subject: vg's

Or a little video in YouTube....



Saludos 

Gary Gower.



"n801bh(at)netzero.com" <n801bh(at)netzero.com> wrote:[quote] With 1700 hours of testing you surely have at least ONE picture of a 701 actually flying in the air with the slats removed.

  I am still waiting to see it. !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 do not  archive

Ben Haas

N801BH

www.haaspowerair.com



-- "secatur" <appraise1(at)bigpond.com> wrote:

--> Zenith-List message posted by: "secatur" <appraise1(at)bigpond.com>



Well, I guess I'll just have to change my mind and build the slats and throw these VG's away !

1700+ hours of independant, documented testing WITHOUT 1 negative report ain't gonna convince me!

And when my 701 is finished I will park it right next to my Wright Flyer, and my Model T ford (Black of course!) right under the big sign that says "EXPERIMENTAL..do not change or alter ever. .or else!!"



ps: Can somebody please post some BAD results with VG's instead of Slats .... so I can feel justified??



Wowie Zowie !





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=================================================nbsp;Please Support Your Lists This Month nbsp;the Contribution link below to find onbsp;    * Aeroware Enterprises www.k=                              -Matt Dralle, List ========================         - The Zeatronics List Features Naviga  Any questions?  Get answers on any topic at Yahoo! Answers. Try it now. [quote][b]

vgstol(at)bigpond.net.au
Guest

Posted: Wed Dec 13, 2006 11:31 am Post subject: vg's

For a photo have a look at www.stolspeed.com , "Benefits of VGs"  page......

  

  

 [quote]   ---

Avidmagnum

Joined: 18 Nov 2006
Posts: 19
Location: Wisconsin, Florida

Posted: Wed Dec 13, 2006 3:11 pm Post subject: Re: vg's

On my 701 amphibian speed at 5500rpm in smooth air, no wind went from 85 to 95mph. (GPS speeds) Part of the speed came from repitching the warp drive prop today(about 3mph). But cutting down drag by removing the slats made this possible. I had done a fair amount of clean up on the 701 already and with  the slats on (with wheels)it would cruise 97mph at 5200 rpm.



The nice part is running 86 or so at about 400 rpm less than before.    That's what I'll be doing most of the time.  Fly....life is short!  Tom in Florida

MaxNr(at)aol.com
Guest

Posted: Thu Dec 14, 2006 10:35 am Post subject: VG's

Question: Would VG's make the plane more resistant to spins?

 

 Bob D

 

 601XL rudder/eng mt  [quote][b]

vgstol(at)bigpond.net.au
Guest

Posted: Thu Dec 14, 2006 6:42 pm Post subject: vg's

Two : the picture was snapped at an  instant in the flare where full AOA had not yet been achieved and there is  more to come.

  

Hey, good analysis of the photo  John.

  

 I don't know if that was the maximum aoa acheivable,  but I note that the elevator is well up.  Now this is an  idle power flare, and we've had problems with lack of elevator  authority in this condition - with a trickle of power sending an airstream over  the tail, the aoa can be increased considerably.

  

 With the darn delay in these low end digital still cameras  I'm lucky to get any of the action at all - usually just get the tail going out  of the picture!  I know about holding the button halfway so that focus is  already set, so then the delay is only 0.2sec, but the button is so  sensitive that I often just get the prop coming into the frame......  I  want to get a camera that can shoot a whole sequence in rapid fire, then go thro  them frame at a time - that would be really interesting to analyse.   

  

  I try not to tell people how to run their  business BUT if I wanted to sell to this tough crowd I'd have more  pictures and several clips on YouTube,  maybe a couple 701's (or  Savannah's) side by side, one with slats the other with VG's doing a drag race  T.O.  Many folks are visual learners, SOME are from Missouri.  

  

 Yeh, I'd just love to do that!  These take-offs that  I can get now with the Savannah with VGs are incredible - I'd really  like to show them off.  Need to get a new video camera.  My old Hi-8  can't seem to focus it's eyes properly any more these days - a problem with  many of us at this stage of life.....   I also want to do a bunch of  tuft testing with remote video - flying close enough with another aircraft is  just too risky for my liking, especially at stall speeds....  I'll start  another thread seeking advice on video cameras for such use.   And,  yeh, I'm as much a sceptic as anyone, but I am open to new developements so long  as they are backed by experience.

  

 Now back to techincal facts.  I haven't done real  outside aoa measurements, but i did mount an inclinometer in the cabin to do  comparisons slats/no slats, flying level at different speeds.  The results  from that are really consistent and interesting when plotted up on graph  paper - wish I knew how to present that graph on this forum.  But  to summarize:

  

 Knots.  Slats  w/o slats    15*flaps

 30          14         15                 12

 35          12         13                    9

 40           9.5        10                  7

 45           6.5        7.5                 4

 50           5            5.5                 2

 55           4            4

 60           3.5        3

 65           2            2

 70           2             1

 75           1            0

 80           0             -1      

  

 If you plot these out they are so consistent that you  would think they were fudged - it's unusual in flight testing to get such  consistency!

 So, at the low end it needs 1* more aoa without slats  and at the high end 1* less without slats, and the cross-over point is 55kts,  which incidentally is also the best rate of climb speed.....

 With 15* flaps, the aoa was the same with slats or no  slats, right thro the range!!

  

 Yeh, this is just getting really interesting now, with  good technical inquiries and suggestions.  I sure as hell don't know  everything, and really looking forward to the analysis of others to expand all  of our knowledge.  I'm an experimenter thro and thro, and NOT  a careless risk-taker, but eager to push the envelope to see what can  be achieved.

  

 JG

  



 [quote]   ---

vgstol(at)bigpond.net.au
Guest

Posted: Thu Dec 14, 2006 6:52 pm Post subject: VG's

I don't know an answer to that Bob.  I see no  reason at all to get into a spin situation, or even a full stall, at least in  these ZAC machines - they're so docile and give so much warning if you practice  'tickling' the stall and learn the feeling.

  

 But I do note that CCI, a long time supplier  of vortex generators, tells of equiping a Pitts with them - the landings  improved muchly, but he couldn't do snap rolls any more!   I  don't know if that relates to spins....

 JG

 [quote]   ---

nyterminat(at)aol.com
Guest

Posted: Thu Dec 14, 2006 6:55 pm Post subject: vg's

John,

  

 Your buddy with the 701, has he considered using 40 degrees of flaps? Apparently this is what Zenith used to allow the 701 to use before they changed to 30 degrees. It would be interesting to see what the stall speed does at 40 degrees. 

  

 Bob Spudis

 N701ZX  CH701/912S

 do not archive

  

  

  

 In a message dated 12/14/06 21:44:56 Eastern Standard Time, vgstol(at)bigpond.net.au writes:

  	  Quote: 	
		     Two : the picture was snapped at an instant in the flare where full AOA had not yet been achieved and there is more to come.

  

Hey, good analysis of the photo John.

  

 I don't know if that was the maximum aoa acheivable, but I note that the elevator is well up.  Now this is an idle power flare, and we've had problems with lack of elevator authority in this condition - with a trickle of power sending an airstream over the tail, the aoa can be increased considerably.

  

 With the darn delay in these low end digital still cameras I'm lucky to get any of the action at all - usually just get the tail going out of the picture!  I know about holding the button halfway so that focus is already set, so then the delay is only 0.2sec, but the button is so sensitive that I often just get the prop coming into the frame......  I want to get a camera that can shoot a whole sequence in rapid fire, then go thro them frame at a time - that would be really interesting to analyse.  

  

  I try not to tell people how to run their business BUT if I wanted to sell to this tough crowd I'd have more pictures and several clips on YouTube,  maybe a couple 701's (or Savannah's) side by side, one with slats the other with VG's doing a drag race T.O.  Many folks are visual learners, SOME are from Missouri. 

  

 Yeh, I'd just love to do that!  These take-offs that I can get now with the Savannah with VGs are incredible - I'd really like to show them off.  Need to get a new video camera.  My old Hi-8 can't seem to focus it's eyes properly any more these days - a problem with many of us at this stage of life.....   I also want to do a bunch of tuft testing with remote video - flying close enough with another aircraft is just too risky for my liking, especially at stall speeds....  I'll start another thread seeking advice on video cameras for such use.   And, yeh, I'm as much a sceptic as anyone, but I am open to new developements so long as they are backed by experience.

  

 Now back to techincal facts.  I haven't done real outside aoa measurements, but i did mount an inclinometer in the cabin to do comparisons slats/no slats, flying level at different speeds.  The results from that are really consistent and interesting when plotted up on graph paper - wish I knew how to present that graph on this forum.  But to summarize:

  

 Knots.  Slats  w/o slats   15*flaps

 30         14         15                12

 35         12         13                  9

 40          9.5       10                 7

 45          6.5       7.5                4

 50          5            5.5                2

 55          4            4

 60          3.5        3

 65          2           2

 70          2           1

 75          1            0

 80          0           -1      

  

 If you plot these out they are so consistent that you would think they were fudged - it's unusual in flight testing to get such consistency!

 So, at the low end it needs 1* more aoa without slats and at the high end 1* less without slats, and the cross-over point is 55kts, which incidentally is also the best rate of climb speed.....

 With 15* flaps, the aoa was the same with slats or no slats, right thro the range!!

  

 Yeh, this is just getting really interesting now, with good technical inquiries and suggestions.  I sure as hell don't know everything, and really looking forward to the analysis of others to expand all of our knowledge.  I'm an experimenter thro and thro, and NOT a careless risk-taker, but eager to push the envelope to see what can be achieved.

  

 JG

	
  

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