Slim Airfoil vs Thick...

I'm just wondering if the TF ARF Nobler could actually turn corners like the Vector 40 or the Impact with the slim airfoil? From what I remember.. the ol' Spectrum fast combat ship I had with the slim airfoil, didn't turn or fly as good as the Nemesis II in response and tightness in turns.

>I'm just wondering if the TF ARF Nobler could actually turn
>corners like the Vector 40 or the Impact with the slim
>airfoil? From what I remember.. the ol' Spectrum fast
>combat ship I had with the slim airfoil, didn't turn or fly as
>good as the Nemesis II in response and tightness in turns.

The ARF Nobler isn't going to turn as tight as the Impact and one of the issues is the airfoil.

Brett

> The ARF Nobler isn't going to turn as tight as the Impact
>and one of the issues is the airfoil.
>
> Brett

Thats what I thought.. ohwell

>>I'm just wondering if the TF ARF Nobler could actually
>turn
>>corners like the Vector 40 or the Impact with the slim
>>airfoil? From what I remember.. the ol' Spectrum fast
>>combat ship I had with the slim airfoil, didn't turn or
>fly as
>>good as the Nemesis II in response and tightness in
>turns.
>
> The ARF Nobler isn't going to turn as tight as the Impact
>and one of the issues is the airfoil.
>
> Brett


Hmmmmm....
Well I know this isn't exactly an argument to what you said and is not intended to be but....
Some of the tightest corners I've ever witnessed on a CL Stunter were flown by Masuro Hiki (last year or the year before), with....wait it can't be....A NOBLER!
Albeit a Geiseki Nobler at VSC. Puny old Fox 35 also....go figure.
Actually the Fox was a real runner, about the best Fox I've ever heard.

Randy C

"From what I remember.. the ol' Spectrum fast combat ship I had with the slim airfoil, didn't turn or fly as good as the Nemesis II in response and tightness in turns."

That's what I remember, too.

Howard Rush
Bellevue, WA

I do realized the rest of the parameter like the weight, tail size, prop choices, flap/elevator Trim etc etc. will also effects the corners. But how far could you make use of the ultra slim (approx 1 5/8" @ root) Airfoil? and is that the main reason others have said that the TF ARF Nobler will only do good soft corners? [photo not recovered: sipcof.gif]

>I do realized the rest of the parameter like the weight, tail
>size, prop choices, flap/elevator Trim etc etc. will also
>effects the corners. But how far could you make use of the
>ultra slim (approx 1 5/8" @ root) Airfoil? and is that
>the main reason others have said that the TF ARF Nobler will
>only do good soft corners? [photo not recovered: sipcof.gif]


Its not just the ARF Nobler, it's the same with any of the Noblers (the ARF is largely based on the "Green Box"). You could help yourself by making the leading edge much blunter (just taking the existing wing and blunting the leading edge as much as you dare would help), but without other changes you also aren't going to get enough torque to overcome the pitching moment from the large flaps.

Blunting the leading edge (I mean changing the airfoil almost completely from the high point forward to a nice parabolic or elliptical shape) and cutting about 3/8-1/2" off the flap chord, along with enlarging the tail moment by about 2" and stabilizer/elevator area by about 30%, changing the stab/elevator split to about 60/40 or 65/35, and most importantly of all, put in something like an Aero-Tiger, Magnum 36, etc. running about 4" of pitch, and then you have something, and the relatively thin airfoil isn't going to be a significant limitation. Of course, what I am describing is more-or-less an Impact Jr. and if you are going to do that you might as well just build a scaled down Impact from scratch. Run the Impact plans through a Xerox machine at about 87% and you will be mostly there.

You might wonder how I came up with this so quickly* - on my building table right now is something approximately like this, a 35-sized model with a more-or-less Nobler wing but otherwise modern dimensions. This is a proof of concept model for the Infinity Jr., the primary difference being that the wing on the real model is about 2" thick at the root.

Brett


p.s. oh, and of course the basic issue with the slow turns was addressed almost 50 years ago - in the Olympic article! Shows cutting down the flap area for "snappier" turns right there in black-and-white.

The alternative would be the Patternmaster/Cardinal approach - create an "irresistable force" (i.e. massive tail volume) to overcome the "immovable object" of the negative pitching moment. But creating "irresistable forces" requires almost irresistable hinge moments, too, meaning you have to have a lot of line tension, which in turn requires you to "manufacture" extra line tension, and thus compromise the trim in other ways to get it. It works a lot better in larger airplanes, since the weight/line tension goes up as the cube of the linear dimensions, and the hinge moment only goes up as ~the square of the linear dimensions. In any case it takes heroic control effort.

>>I do realized the rest of the parameter like the weight,
>tail
>>size, prop choices, flap/elevator Trim etc etc. will
>also
>>effects the corners. But how far could you make use of
>the
>>ultra slim (approx 1 5/8" @ root) Airfoil? and is
>that
>>the main reason others have said that the TF ARF Nobler
>will
>>only do good soft corners? [photo not recovered: sipcof.gif]
>
>
> Its not just the ARF Nobler, it's the same with any of
>the Noblers (the ARF is largely based on the "Green
>Box"). You could help yourself by making the leading edge
>much blunter (just taking the existing wing and blunting the
>leading edge as much as you dare would help), but without
>other changes you also aren't going to get enough torque to
>overcome the pitching moment from the large flaps.
>
> Blunting the leading edge (I mean changing the airfoil
>almost completely from the high point forward to a nice
>parabolic or elliptical shape) and cutting about 3/8-1/2"
>off the flap chord, along with enlarging the tail moment by
>about 2" and stabilizer/elevator area by about 30%,
>changing the stab/elevator split to about 60/40 or 65/35, and
>most importantly of all, put in something like an Aero-Tiger,
>Magnum 36, etc. running about 4" of pitch, and then you
>have something, and the relatively thin airfoil isn't going to
>be a significant limitation. Of course, what I am describing
>is more-or-less an Impact Jr. and if you are going to do that
>you might as well just build a scaled down Impact from
>scratch. Run the Impact plans through a Xerox machine at
>about 87% and you will be mostly there.
>
> You might wonder how I came up with this so quickly* - on
>my building table right now is something approximately like
>this, a 35-sized model with a more-or-less Nobler wing but
>otherwise modern dimensions. This is a proof of concept model
>for the Infinity Jr., the primary difference being that the
>wing on the real model is about 2" thick at the root.
>
> Brett
>
>
>p.s. oh, and of course the basic issue with the slow turns was
>addressed almost 50 years ago - in the Olympic article! Shows
>cutting down the flap area for "snappier" turns
>right there in black-and-white.
>
> The alternative would be the Patternmaster/Cardinal
>approach - create an "irresistable force" (i.e.
>massive tail volume) to overcome the "irresistable
>force" of the negative pitching moment. But creating
>"irresistable forces" requires almost irresistable
>hinge moments, too, meaning you have to have a lot of line
>tension, which in turn requires you to "manufacture"
>extra line tension, and thus compromise the trim in other ways
>to get it. It works a lot better in larger airplanes, since
>the weight/line tension goes up as the cube of the linear
>dimensions, and the hinge moment only goes up as ~the square
>of the linear dimensions. In any case it takes heroic control
>effort.
>

Ditto!!!
John Sunderland

Brett –

“ . . . on my building table right now is something approximately like this, a 35-sized model with a more-or-less Nobler wing but otherwise modern dimensions. This is a proof of concept model for the Infinity Jr., the primary difference being that the wing on the real model is about 2" thick at the root. . . .”

OK, I’ll send $200 for a set of plans. Reading of the Wimpact adventure certainly triggered thoughts of a 35-40 size “Impfanity” in a lot of folks' minds, I’m sure. That sounds like a lot more like an “off-the-board-first-pass winner” than a “proof-of-concept” model.

“ . . . Blunting the leading edge (I mean changing the airfoil almost completely from the high point forward to a nice parabolic or elliptical shape) and cutting about 3/8-1/2" off the flap chord, along with enlarging the tail moment by about 2" and stabilizer/elevator area by about 30%, changing the stab/elevator split to about 60/40 or 65/35, . . . Run the Impact plans through a Xerox machine at about 87% and you will be mostly there. . . .”

Or Vector 40 plans at 100% for a slightly more “Noblerish” rendition. (The Vector has less of a change in flap area and tail moment than your numbers, but in the same direction, as you know) A pretty interesting exercise is to lay GB Nobler plans over Vector 40 plans.

Larry Fulwider

>Brett –
>
>“ . . . on my building table right now is something
>approximately like this, a 35-sized model with a more-or-less
>Nobler wing but otherwise modern dimensions. This is a proof
>of concept model for the Infinity Jr., the primary difference
>being that the wing on the real model is about 2" thick
>at the root. . . .”
>
>OK, I’ll send $200 for a set of plans. Reading of the
>Wimpact adventure certainly triggered thoughts of a
>35-40 size “Impfanity” in a lot of folks' minds, I’m sure.
>That sounds like a lot more like an “off-the-board-first-pass
>winner” than a “proof-of-concept” model.

There are those who think otherwise, and that a small airplane doesn't "present" as well. I figure based on what I have seen from the judging, that making fewer mistakes seems to matter a whole lot more than "presentation" and if I can make fewer mistakes with a smaller airplane it will be to the good.


>“ . . . Blunting the leading edge (I mean changing the
>airfoil almost completely from the high point forward to a
>nice parabolic or elliptical shape) and cutting about
>3/8-1/2" off the flap chord, along with enlarging the
>tail moment by about 2" and stabilizer/elevator area by
>about 30%, changing the stab/elevator split to about 60/40 or
>65/35, . . . Run the Impact plans through a Xerox machine at
>about 87% and you will be mostly there. . . .”
>
>Or Vector 40 plans at 100% for a slightly more
>“Noblerish” rendition. (The Vector has less of a change in
>flap area and tail moment than your numbers, but in the same
>direction, as you know) A pretty interesting exercise is to
>lay GB Nobler plans over Vector 40 plans.

If you want to start with a Vector instead of a Nobler you are much further ahead. The Vector 40 is far and away the best 35-sized plane I have seen. Far better than the Cardinal and not tail-volume-limited like most of the good classic planes. I would be tempted to make only one change to the Vector, but I am not even sure that the "change" = "improvement". Part of my experiment would be to see if the change actually helped anything, changed it subjectively better for my personal desire as far as control response goes, or just messes it up.

Brett

> . . .
>I would be tempted to make only one change to the Vector, but
>I am not even sure that the "change" =
>"improvement". . . .
> . . .
>
> Brett

Hey, you can't stop there! At least a hint?

Larry Fulwider

Thanks for the in depth infos.

>in the Olympic article! Shows
>cutting down the flap area for "snappier" turns

What if the flaps were set up 2>3 (ratio to the elevator), instead of 1>1. would that help?

Proof of concept??

Brett,

Charley Mackey and John Simpson beat you to the prof of concept on the thicker wing about 50 years ago, and I beat you to the larger stab/elevator area about 40 years ago. Lew McFarland beat you to the longer moment arms about 50 years ago too, that is if my memory is correct? Sooo, I guess your prof of concept should work magnificently! Oh yeah, watch out about getting noses too long, we found out that's not a good idea on Mike's Gypsy! Although, he did get the plane to work O.K. before the '73 Nat's

Jim Pollock,

>Proof of concept??
>
>Brett,
>
>Charley Mackey and John Simpson beat you to the prof of
>concept on the thicker wing about 50 years ago, and I beat you
>to the larger stab/elevator area about 40 years ago. Lew
>McFarland beat you to the longer moment arms about 50 years
>ago too, that is if my memory is correct? Sooo, I guess your
>prof of concept should work magnificently!

I forget, which 60-90-sized tuned-pipe airplanes were they competing against again?

The concept is to apply the stuff we have learned over the past 25-years or so with regard to trim, power, and control feel, to a smaller package. Maybe the parts were there a long time ago, but even Bill Werwage (in the GeoBolt article) observed that they made the airplanes bigger but not necessarily better.

Brett

Well,

John Simpson frequently competes against Cutis Comer who has a pipe on his LA .40 powered Tutor. The Tutor flys O.K. but the Cavalier flys rings around it!

Jim Pollock

>
> I forget, which 60-90-sized tuned-pipe airplanes were they
>competing against again?
>
> The concept is to apply the stuff we have learned over the
>past 25-years or so with regard to trim, power, and control
>feel, to a smaller package. Maybe the parts were there a long
>time ago, but even Bill Werwage (in the GeoBolt article)
>observed that they made the airplanes bigger but not
>necessarily better.
>
> Brett
>
>

I presume this "jr" infinity is still going to have a 40VF or ROJett 61 under the hood?

Steve

Given the bad influence Brett and Dan have on each other, I can imagine something half or a third as big.

Howard Rush
Bellevue, WA

>>
>> I forget, which 60-90-sized tuned-pipe airplanes were
>they
>>competing against again?
>>
>> The concept is to apply the stuff we have learned over
>the
>>past 25-years or so with regard to trim, power, and
>control
>>feel, to a smaller package. Maybe the parts were there a
>long
>>time ago, but even Bill Werwage (in the GeoBolt article)
>>observed that they made the airplanes bigger but not
>>necessarily better.
>>
>> Brett
>>
>>
>
>I presume this "jr" infinity is still going to have
>a 40VF or ROJett 61 under the hood?
>

Well, on that one I *do* have to admit someone else is going to beat me to the punch. An item closely resembling that just got its wing attached this last Saturday and will almost certainly be at the NATs. I don't want to spoil the surprise more than that.

Brett

>>I presume this "jr" infinity is still going to
>have
>>a 40VF or ROJett 61 under the hood?
>>
>
> Well, on that one I *do* have to admit someone else is
>going to beat me to the punch. An item closely resembling that
>just got its wing attached this last Saturday and will almost
>certainly be at the NATs. I don't want to spoil the surprise
>more than that.
>
> Brett

Thats okay. Our East coast downsized Doomsday machine is undergoing an engine change before resuming flight testing. Regrettably, ours is but an R&D airplane and will not be making its debut at Muncie. I do look forward to seeing the plane you are referring to at the Nats.

Steve

>>I do realized the rest of the parameter like the weight,
>tail
>>size, prop choices, flap/elevator Trim etc etc. will
>also
>>effects the corners. But how far could you make use of
>the
>>ultra slim (approx 1 5/8" @ root) Airfoil? and is
>that
>>the main reason others have said that the TF ARF Nobler
>will
>>only do good soft corners? [photo not recovered: sipcof.gif]
>
>
> Its not just the ARF Nobler, it's the same with any of
>the Noblers (the ARF is largely based on the "Green
>Box"). You could help yourself by making the leading edge
>much blunter (just taking the existing wing and blunting the
>leading edge as much as you dare would help), but without
>other changes you also aren't going to get enough torque to
>overcome the pitching moment from the large flaps.
>
> Blunting the leading edge (I mean changing the airfoil
>almost completely from the high point forward to a nice
>parabolic or elliptical shape) and cutting about 3/8-1/2"
>off the flap chord, along with enlarging the tail moment by
>about 2" and stabilizer/elevator area by about 30%,
>changing the stab/elevator split to about 60/40 or 65/35, and
>most importantly of all, put in something like an Aero-Tiger,
>Magnum 36, etc. running about 4" of pitch, and then you
>have something, and the relatively thin airfoil isn't going to
>be a significant limitation.

Actually, if you just want to take a ARF Nobler and improve the performance relatively easily, just use the stock parts, blunt the LE by sanding it down as much as you dare, and replace the stock stab/elevator with one with about 130 square inches total - say, a span of 21.5", an average stabilizer chord of 3 5/8", an average elevator chord of 2.5", tapered to match the original with similar construction, or to meet your own personal vision. Then slightly alter the fuse cutout to match the stab, and glue it in place of the original, with the hinge line in the same place. Make the tail airfoil about like the original, just bigger. Trimming about 1/4" off the flaps will probably help, too. It won't be as good as the aforementioned Impact Jr, but it will be a lot better than stock, not be so sensitive to CG position, and corner better.

Of course I haven't actually tried it, and although it's going to be a lot like a 35-sized Genesis (except with a low-aspect ratio tail).

Brett

> Actually, if you just want to take a ARF Nobler and
>improve the performance relatively easily, just use the stock
>parts, blunt the LE by sanding it down as much as you dare,
>and replace the stock stab/elevator with one with about 130
>square inches total - say, a span of 21.5", an average
>stabilizer chord of 3 5/8", an average elevator chord of
>2.5", tapered to match the original with similar
>construction, or to meet your own personal vision. Then
>slightly alter the fuse cutout to match the stab, and glue it
>in place of the original, with the hinge line in the same
>place. Make the tail airfoil about like the original, just
>bigger. Trimming about 1/4" off the flaps will probably
>help, too. It won't be as good as the aforementioned Impact
>Jr, but it will be a lot better than stock, not be so
>sensitive to CG position, and corner better.
>
> Of course I haven't actually tried it, and although it's
>going to be a lot like a 35-sized Genesis (except with a
>low-aspect ratio tail).
>
> Brett


Thanks Brett. I'll give your suggestion above a try.

>
>Thanks Brett. I'll give your suggestion above a try.

The most important thing is THE ENGINE, it pretty well trumps anything you are likely to do with the aerodynamics.

Brett

>
>>
>>Thanks Brett. I'll give your suggestion above a try.
>
> The most important thing is THE ENGINE, it pretty well
>trumps anything you are likely to do with the aerodynamics.
>
> Brett
>

I have an OS.46LA I'm thinking of using on the Nobler.

Brett,
Sounds like a certain Cardinal I know...

>Sounds like a certain Cardinal I know...

Aside from the airfoil, and not considering the low-aspect-ratio tail. And the cutting down on the flaps.

Brett

>"From what I remember.. the ol' Spectrum fast combat
>ship I had with the slim airfoil, didn't turn or fly as good
>as the Nemesis II in response and tightness in turns."
>
>That's what I remember, too.
>
>Howard Rush
>Bellevue, WA

Hmmm, just wondering who the heck designed the Nemesis anyways?

The Nemisis was designed by PTG but somehow one of his flying buddies has gotten credit for it. Some jerk named Howard something or other. I forgot.


Later, John

hmm...do you need a bunch of turn?

If you go back 70 years or so one of the old NACA reports(highly classified until after WW-II) showed that at lower Reynold numbers(<500K range)thicker wings, up to 21%, had better lift/drag than thinner wings. Over 1,000,000 or so the thinner wings start to do better. If PTG could have just got his Nemesis up to 140-150 miles an hour it would have turned even better. Wild Bill's Equalizer, with the 0018 airfoil, was just about right for the times.

Stop that.

Howard Rush
Bellevue, WA

Alice was right; "Things are getting curiouser and curiouser."

>If you go back 70 years or so one of the old NACA
>reports(highly classified until after WW-II) showed that at
>lower Reynold numbers(<500K range)thicker wings, up to 21%,
>had better lift/drag than thinner wings. Over 1,000,000 or so
>the thinner wings start to do better. If PTG could have just
>got his Nemesis up to 140-150 miles an hour it would have
>turned even better. Wild Bill's Equalizer, with the 0018
>airfoil, was just about right for the times.

The Equalizer was a dandy flying airplane! My buddy Bob Emmett went a significant step further (many years ago) with a similar stabilated flying wing that had a "much" thicker airfoil. I've no clue how much thicker but it was apparently too much since it wouldn't hardly turn at all. Don't remember much else about it so I can't state with confidence the really, really thick wing was the culprit.

Ted Fancher

AND that, is the THICK and THIN of it all!

Jim Pollock

>The Equalizer was a dandy flying airplane! My buddy Bob
>Emmett went a significant step further (many years ago) with a
>similar stabilated flying wing that had a "much"
>thicker airfoil. I've no clue how much thicker but it was
>apparently too much since it wouldn't hardly turn at all.
>Don't remember much else about it so I can't state with
>confidence the really, really thick wing was the culprit.
>
>Ted Fancher

I guess there's a limit to everything.. [photo not recovered: sipcof.gif]

>If you go back 70 years or so one of the old NACA reports...showed that at lower Reynold numbers(<500K range)
>thicker wings, up to 21%, had better lift/drag than thinner wings.

TN 364 of 2/31 (before they straightened out the "effective" Reynolds numbers?) compares the various NACA 00xx sections from RN = 100,000 to 8,000,000. 'must be ordered.

TR 586 of 6/24/36 (after Tunnel interference and RN's were re-sorted) tells the story through 0018 section. This one's available for as PDF file for free downloading or printing on NASA Tech Report Server site:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930091662_1993091662.pdf

Look at Fig. 28.

Others fill in gaps.

SK

Fig. 28 is why the aforementioned Nemesis airfoil is 16.5% thick. I lived near a library that had those NACA reports.

Howard Rush
Bellevue, WA

I bet the average root cord of any modern ship is nearly the same as the Nobler. However, your average 18% airfoil with 10" root, and around 60" span would hardly stay attached in a 10G turn, built conventionally. Therefore, a thicker airfoil is better for the weight and desired airspeed we like to fly, possibly not as much as I have used in the past. Noblers were over flapped and the "Original" by Brodak is just plain weird. 2 1/2 assymetry and a larger inboard flap root also. Banks out, upright and inverted and causes a noticeable wobble in the intersections. Granted the 57 is the benchmark kit airplane but we have come a long way since then.

John Sunderland

Dan Banjok's Vista has a fat airfoil. Obese. He finished 7th, just out of the money at the last NATS. Also, minimum leading edge sweep. I think he plans a slightly thinner airfoil for the next bird. The big Vista is currently lugged around by a Saito 72, though a PA 75 should be arriving any day. Dan will mount the PA on the Vista, if it isn't necessary to graft on a new nose. Danny flies the weird winds as well as anybody. Scores well in more conducive conditions as well. Plane or the pilot? Plane and the pilot?

>Dan Banjok's Vista has a fat airfoil. Obese. He finished 7th,
>just out of the money at the last NATS. Also, minimum leading
>edge sweep. I think he plans a slightly thinner airfoil for
>the next bird.

Just curious how thick is the fat airfoil? ( __" @ root, etc) [photo not recovered: sipcof.gif]

I'll catch up with Dan in the next few days and get the measurements. I do have a rib template for a Brown B2 that he designed using a thickened Twister wing. Beautiful plane I am working on at the moment (mostly in my mind). The Twister is, of course, a constant chord design. Years ago when I got back into our hobby I stuck a Twister rib up against rib plans for a Mustant. Tah Dah a matching corpulence. Tho the Mustant for some reason looked plumper. I believe the Twister/Mustant airfoil is a 22% section. The Brown B2 is thicker. How about 23.5% (or more, the horror!). I'd say this is indicative of Dan's outlook. Tho I doubt the Vista is quite this extreme. In any case the last I heard Dan plans to make the airfoil for his next design somewhat thinner than the Vista's. For the most part Dan is happy with the handling of the V. The thick wing works, even in adverse wind, at least that is true with Dan wiggling the handle. (Again is it plane or pilot or plane and pilot). But the airfoil is power hungry, even a challenge for a Saito 72 running at a good clip. Hence the PA 75 on order.

Measurements for the Brown B-2 airfoil 8.25"x1.95".

Let's flip the discussion a bit. What if Dan's approach is 100% wrong headed. Guess he'd be a world champ flying an IMPACT or it's derivative. Which means, I suppose, that Dan's design numbers are doable, workable, a viable option, probably as valid (or almost as valid) as the thin airfoil newer Stunt war wagons. Bradley Walker has written an academic treatise on different Schools of Stunt. Nice West Coast/East Coast schism (in design) including some Southeast variations of thought. The discussion has been so mannerly. If you haven't read it, it's over there in the udder forum. Certainly it'll make someone see red. True, summer approaches, most of us about to released from our basement/garage/garret(my exile)-- flying does add joy to many of our lives, blunting the bickering curmudgeon instincts. Nevertheless. Where are the zealots for the different approaches. WHEN will the gloves come off! How will learn anything by being so nice. In the old days...

Beside, Bradley thoughts are published in...

Jokes (and jibes) aside. Dan's approach seems to be an extension of what Bradley calls the Big Jim/Patternmaster idea. The Vista a bigger (fatter airfoil) variant pulled around by a powerful engine tuned to make power.

Bradley Walker has written an academic treatise on
>different Schools of Stunt. Nice West Coast/East Coast schism
>(in design) including some Southeast variations of thought.
>The discussion has been so mannerly. If you haven't read it,
>it's over there in the udder forum. Certainly it'll make
>someone see red.

Huh? See red? For what?

Blue?

>Blue?

I must admit, I get a little tired of being accused of controversy where none lies... there certain is none here. In fact, the entire article is complementary of just about everyone mentioned.

I also believe this article is pretty darn accurate.

I guess Dan flies the hot eastern style. Powerful engine, thick airfoil. The Vista, perhaps, an Ultra Patternmaster. Dan wanting more drive in the maneuvers, even with the big Saito pulling hard. The V bird is that big and draggy.

I brought your article up here, because I think it's relevant to this discussion. A useful classification of styles. Also an insightful warning, when you note that most folks fly a middle style stunter, not West Coast, not East Coast, etc. Not a thick airfoil high powered plane or a thinner airfoil bird with a loafing engine. The middle style, in your opinion, is a least effective choice. Well, IMHO, that's worth observation and thinking about.

As far as controversy goes, so what. Hard for me to believe that Godzilla is thin skinned. In any case, I didn't attack your POV. I find it suggestive and useful. I regard bringing it up here as a complement to what you wrote.

I described Dan's plane on this thread because it's an extreme approach that works. At least with him at the handle.

Someone once suggested using emoticons when attempting to write tongue in cheek. I hate emoticons.

>As far as controversy goes, so what. Hard for me to believe
>that Godzilla is thin skinned. In any case, I didn't attack
>your POV. I find it suggestive and useful. I regard bringing
>it up here as a complement to what you wrote.

I am not thin skinned...

Keep in mind, I did not attack anyone's POV either.

I think it is good article, and timely, considering the new rules changes. I do appreciate the compliment

>>The discussion has been so mannerly. If you haven't read
>it,
>>it's over there in the udder forum. Certainly it'll make
>>someone see red.
>
>Huh? See red? For what?

I don't see it either, however, the entire history of this event is filled with people going on the warpath over offhand comments. There are people who go ballistic even for mentioning their name, or for commenting on them or their approach/airplane/engine without prefacing it with some absurdly effusive praise. So I can see what Dennis is commenting on, even if I think there isn't anything particularly offensive - it doesn't take "particularly offensive" to set some people off.

Brett

>
>>>The discussion has been so mannerly. If you haven't
>read
>>it,
>>>it's over there in the udder forum. Certainly it'll
>make
>>>someone see red.
>>
>>Huh? See red? For what?
>
> I don't see it either, however, the entire history of this
>event is filled with people going on the warpath over offhand
>comments. There are people who go ballistic even for
>mentioning their name, or for commenting on them or their
>approach/airplane/engine without prefacing it with some
>absurdly effusive praise. So I can see what Dennis is
>commenting on, even if I think there isn't anything
>particularly offensive - it doesn't take "particularly
>offensive" to set some people off.
>
> Brett

Well, all I can say is everything that was written was meant to be complimentary.

>>comments. There are people who go ballistic even for
>>mentioning their name, or for commenting on them or their
>>approach/airplane/engine without prefacing it with some
>>absurdly effusive praise. So I can see what Dennis is
>>commenting on, even if I think there isn't anything
>>particularly offensive - it doesn't take
>"particularly
>>offensive" to set some people off.
>>
>> Brett
>
>Well, all I can say is everything that was written was meant
>to be complimentary.

I think you are still missing my point - merely "complimentary" is, for a few people, grossly inadequate. Gushing, effusive, cloyingly worshipful is required.

Please don't misunderstand - I agree with you on this particular topic, it shouldn't be that way. But Dennis is making what could be an accurate prediction of what could happen with a few people. I know I have gotten it from various people over the years for what I thought were pretty innocuous or mildly complimentary comments. In fact I made one earlier today and am hearing about it. Just be prepared!

Brett

Ah, heck Brett. I am used to it.

The best set of triangles I have ever seen flown was flown with an ARF Nobler. 40 points, no room for improvement no matter how thick your wing is. The second set flown by the same flier was not as good. I don't recall what I scored the second set. I've never seen another set of 40 point triangles.

>The best set of triangles I have ever seen flown was flown
>with an ARF Nobler. 40 points, no room for improvement no
>matter how thick your wing is. The second set flown by the
>same flier was not as good. I don't recall what I scored the
>second set. I've never seen another set of 40 point triangles.
>

And that's really a key point. We can sit here and talk airfoils all afternoon, and do, but it's how the airplane is trimmed, powered, and flown that matters.

Brett

>>The best set of triangles I have ever seen flown was
>flown
>>with an ARF Nobler. 40 points, no room for improvement no
>>matter how thick your wing is. The second set flown by
>the
>>same flier was not as good. I don't recall what I scored
>the
>>second set. I've never seen another set of 40 point
>triangles.
>>
>
> And that's really a key point. We can sit here and talk
>airfoils all afternoon, and do, but it's how the airplane is
>trimmed, powered, and flown that matters.
>
> Brett


Man, you said a mouthful there..

The "that can't win" or the "there is no way that little plane beat this super duper high techno *whatever*" really needs to be eliminated from our hobby.

>
>Man, you said a mouthful there..
>
>The "that can't win" or the "there is no way
>that little plane beat this super duper high techno
>*whatever*" really needs to be eliminated from our
>hobby.


Arguing about aerodynamics provides an excellent way to waste time between contests. There are a *few* things that matter, but they are details (like the LE shape) but if you have a good engine you can hang it on almost anything with some degree of success. At least for the past 20 years or so.

Brett

Dan doesn't know the dimensions of the Vista airfoil off hand. Thinks the root rib is 3inches high. He'll measure sometime this week. He agrees it's fat, very fat. The shape and thickness were copied from a Windy design with a lot of thickness taper. Dan tapered it less. He kept the lead edge nearly straight, there's only a slight sweep back, in order to get the look he wanted-- 30s pylon racer. His Bob Hunt designed Mustang had a more friendly feel. Best flying plane Dan's tried recently was Joe Adamusko's Spitfire. (Seafire?)

So. There it is. Contest season hits the East Coast in late May, early June. Weather's too nice to waste tho.

>Dan doesn't know the dimensions of the Vista airfoil off
>hand. Thinks the root rib is 3inches high. He'll measure
>sometime this week. He agrees it's fat, very fat. The shape
>and thickness were copied from a Windy design with a lot of
>thickness taper. Dan tapered it less. He kept the lead edge
>nearly straight, there's only a slight sweep back, in order to
>get the look he wanted-- 30s pylon racer. His Bob Hunt
>designed Mustang had a more friendly feel. Best flying plane
>Dan's tried recently was Joe Adamusko's Spitfire. (Seafire?)
>
>So. There it is. Contest season hits the East Coast in late
>May, early June. Weather's too nice to waste tho.
>
>

For the sake of argument, I still think Suzy Q flew better. But, having said that, the Vista flight in round 2 at Brodaks (the one the rain robbed him on) was one of the best flights I have ever seen, one of those where you stand there watching and thinking "there's no way he can keep it together through the eights/hourglass/overhead..." and then finally you watch him nail the landing and you're just amazed. I'll be curious to see if he gets that PA in it by summertime and what he thinks.
ps, did he ever get the smashed up MiG repaired?

Steve

Hey Steve,

The Suzie Q is the Bob Hunt Mustang, of course. Dan is on the fence about whether Suzie flies better than the Vista. Thought the Bob Hunt plane hit a groove easier. Yeah, that Vista flight at Brodak was a show stopper.

The Mig is on it's way. Hard to straighten crumpled thin aluminum. But, it's Dan. Dan calls the "kit" he used for the Mig, more a hint than a kit. Since he had to re-engineer everything, and fabricate many aluminum parts. For those who haven't seen it, the Mig is an aluminum control line scale bird, powered by an OS pulse jet, a spectacular fire belching noisy beast. The OS engine is a 60% scaled down copy of a Dyna Jet. The OS engine mounts within the fuse of the Mig. It's been flying for a couple of years by now. Always a show. It crashed at Huntersville. No doubt it will be back.

Whenever your name comes up, Dan mutters, I hope Steve doesn't get more power for that plane... he'll be hard to beat...

Best,
Dennis

>Hey Steve,
>
>
>Whenever your name comes up, Dan mutters, I hope Steve doesn't
>get more power for that plane... he'll be hard to beat...
>
>Best,
>Dennis

Tell Dan that I am working on a new plane, piped PA-61 powered. That should make him happy.....

Dan Bankjok's Vista:

Span 62"
Root rib without flap- 10.75" x 2.875" (.267) plus 3" width flap.
Tip rib without flap- 9.75" x 2.5", 6" from tip flap width is 2.25"
from 6" point flap curves to zero width at tip

>Dan Bankjok's Vista:
>
>Span 62"
>Root rib without flap- 10.75" x 2.7/8" (.267) plus
>3" width flap.

So, not 26.7%, 21%.

Brett

Yeah Brett, but wasn't there a debate about whether or not the chord percentage included the flap or not. Dunno. I'm not sure of the convention. But I believe Al Rabe, way back when, did not include the flap when computing the percentages.

>Dan Banjok's Vista has a fat airfoil. Obese. He finished 7th,
>just out of the money at the last NATS. Also, minimum leading
>edge sweep. I think he plans a slightly thinner airfoil for
>the next bird.

Just curious how thick is the fat airfoil? ( __" @ root, etc)


>Dan Bankjok's Vista:
>
>Span 62"
>Root rib without flap- 10.75" x 2.7/8" (.267) plus
>3" width flap.
>Tip rib without flap- 9/35" x 2.5", 6" from tip
>flap width is 2.25"
> from 6" point flap curves to zero width at tip
>
>
Thanks for the infos. that sounds like a real aggressive design.

Just noticed the typos.
root: 10.75x2.875
tip: 9.75x2.50

flap 3" at root, 2.25" 6" from tip. From 6" point to end of wing, flap curves down to zero width.

Weird, Brett's copy of my posted specs has typos, but the original post does not.

>Weird, Brett's copy of my posted specs has typos, but the
>original post does not.

Why, it's almost as if someone edited the original post after I quoted it!

Brett

Ahh, the rocket scientist figures it out. Darn. Are you a rocket scientist? Do I remember that right? You must have jumped on the original post pretty fast.

Sorry Jim, nobody comes close on the corners in the triangles, not even a light Nobler. There are plenty of opportunities for real 40 pt maneuvers in the pattern, but not any of the tricks with corners.

Phil, I was there judging, and I saw perfect triangles. Sorry, I didn't realize you were there also. Even so, you were not judging so your opinion does not matter even if it had had been correct.

I have seen a name-brand judge issue 40 points for a pair of triangles.

Howard Rush
Bellevue, WA

I assumed someone has achieved the 1.5m radius corners then if it was a 40 /40 perfect score.

Joe, I agree with Phil, based on my own experments, that few, if any, airplanes can achieve the 1.5 M radius corners. However, judges judge on what they SEE, not what is really happening. In the Nobler judging incident mentioned above, I SAW what APPEARED to be 1.5 M radius corners, six of them. (Maybe they looked tigher than that, perhaps I should have taken of a point for too tight corners ) Judges must call them the way we see them. Surely you would not have us do anything different.

> Judges must call
>them the way we see them.

That's ALL the pilots could ever ask of a judge. No preconceived notions.

Brett

>> Judges must call
>>them the way we see them.
>
> That's ALL the pilots could ever ask of a judge. No
>preconceived notions.
>
> Brett

I agree. If that is as good as it gets, as square as it gets, then give it 40 points. That is the number of points available for each maneuver, and if it can't be done better than it deserves 40 points.

As to what the judges see, When George Aldrich drew up the rules with the five foot corners, that is what they appeared to him to be at the time. Even if it has been proven that it is impossible, the appearance is still there. If it appears to be what the rules ask for, then that is how it should be judged.

No one runs around the circle measuring the bottoms or the 45 degree marks. Judges have to go by appearances. It is not an exact science (unfortunately). In golf you hit the ball until it falls into the hole. In bowling you count the number of pins that are nocked down. In baseball the pitcher throws at an imaginary strike zone and the umpire judges whether or not it appeared to have gone over or through that zone. Usually they are right. Sometimes they are wrong. But there is no room for argument. Same here. If it appears to be there, then give it 40 points.