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Author Topic: Tail aspect ratio and its effects  (Read 1514 times)

Offline Mike Alimov

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Tail aspect ratio and its effects
« on: September 10, 2019, 01:17:34 PM »
I don't recall much discussion on the topic of the aspect ratio of (horizontal) tail surfaces.  [If there was - please provide citation or reference/link].  I've seen discussions of tail area as a % of wing area, tail moment, airfoil and leading edge radius. 

 I can think of pretty successful planes with pretty high (Stiletto) and pretty low (some Impacts) tail aspect ratios.  All seem to fly fine - I haven't flown them all, and I'm afraid I won't have time to experiment with this variable before winter sets in.

I would expect the higher aspect ratio tail to be more effective as a lifting surface, thus probably requiring less deflection - thus less drag in corners, not a bad thing, eh?

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Offline phil c

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Re: Tail aspect ratio and its effects
« Reply #1 on: September 10, 2019, 03:13:01 PM »
from my  own experiments, a 25% of wing area stab with the elevator chord 30-60% of the chord.  A tail volume coefficient in the 25-30 range.  Lower aspect ratio on the tail seems to give a less abrupt control, say between 4 and 5.
A good pilot can learn how to make almost any plane fly well, so the effective design range is pretty large.

Read what Igor Burger has done with exponential flaps and fine tuning the stab incidence, airfoil, and position.
You could do a lot worse than his MAX II design.  With modern stunt power plants drag isn't much of a consideration.  Just put on a bigger engine or motor.
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Online Brett Buck

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Re: Tail aspect ratio and its effects
« Reply #2 on: September 10, 2019, 10:28:07 PM »
I don't recall much discussion on the topic of the aspect ratio of (horizontal) tail surfaces.  [If there was - please provide citation or reference/link].  I've seen discussions of tail area as a % of wing area, tail moment, airfoil and leading edge radius. 

 I can think of pretty successful planes with pretty high (Stiletto) and pretty low (some Impacts) tail aspect ratios.  All seem to fly fine - I haven't flown them all, and I'm afraid I won't have time to experiment with this variable before winter sets in.

I would expect the higher aspect ratio tail to be more effective as a lifting surface, thus probably requiring less deflection - thus less drag in corners, not a bad thing, eh?

  Tail aspect ratio has been extensively discussed in the past. The Impact, Trivial Pursuit, ThunderGazer, and Infinity all have relatively low aspect ratios, which is I think is the correct solution. Mine is about 4.5:1. The split between the elevator and stabilizer should be somewhere between 66/33 to 60/40.

   The reason is that this seems to make it more likely to have the "lock-in" bottom and tracking with aft CGs, which all of us more-or-less copied from Gid Adkission's "Bud Light" Laser. Those that don't have it, and are otherwise excellent airplanes, always seem "vague" to me around neutral, the most notable being the Yatsenko Shark, which while it is a decently "honest" airplane and doesn't do anything unexpected when you control it, never seems to have any particular interest or tendency to fly in straight lines without constant attention. It will do it just fine - Orestes being noted for it - but it requires far, far more attention to be paid to make it that way.

   I don't know why, and since this dead horse has been beaten to a fine powder many times in the past, don't really want to start an argument on the topic, but that's what I think you should do.

     BTW, I am not sure how Phil is computing TVC, but a typical number for a modern stunt plane is on the order of .45 to .5.

     Brett

Online Brent Williams

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Re: Tail aspect ratio and its effects
« Reply #3 on: September 11, 2019, 11:45:48 AM »
Not to be too pedantic, but I believe the stab/elev aspect ratio is around 3.5:1 on the impact, thunder gazer, infinity, ect.
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Offline Mike Alimov

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Re: Tail aspect ratio and its effects
« Reply #4 on: September 11, 2019, 02:52:18 PM »
Sorry if I missed the beating of this particular dead horse.  I have re-read Igor's Max Bee article, and did not find a discussion of the tail aspect ratio (I believe it is around 4.5).  I went back to the Imitation article, and found this:
"Again, it is important to remember that the force which causes pitch change comes from the lift produced by the entire tail, not solely by the amount of surface we are deflecting into the slipstream.  Therefore, what we are looking for is an efficient lift-producing surface. Probably the most efficient tail would have an elevator which comprised approximately 25% of the total tail surface - something like the FliteStreak, which everyone knows will outmaneuver the more conventional-tailed Ringmaster hands down.
There is, however, some compromise necessary in terms of drag and stability which makes larger than optimum elevators result in an aircraft which is more stable while maneuvering. Since moving the center of drag aft is stabilizing in its effect, and since a certain amount of drag comes hand in hand with the lift the tail produces to maneuver, it is apparent that at the sacrifice of a little more drag we can build an airplane which is more controllable while maneuvering, and which has less tendency to overshoot headings. For this same reason, the thicker tail was employed along with a lower aspect ratio.  Such a tail won't be the most efficient in terms of maximum rate of turn, but will come close, and the net effect will enhance the overall flyability of the airplane.  As a result of these compromises, the Imitation has a tail which totals 140 sq.in., of which 55% is stabilizer and 45% elevator.  The aspect ratio of the tail is 4.5 to 1."
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Offline Tim Wescott

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Re: Tail aspect ratio and its effects
« Reply #5 on: September 11, 2019, 03:24:05 PM »
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The problem with electric is that once you get the smoke generator and sound system installed, the plane is too heavy.

Online Brent Williams

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Re: Tail aspect ratio and its effects
« Reply #6 on: September 11, 2019, 07:22:06 PM »
The MaxBee uses an unconventionally large tail. 
From my measurements of Igor's plans, the tail is 30" wide, approximately 212 in.sq, with a 4.25:1 aspect ratio.  Big!  Roughly 32% of the wing area.

Works pretty well for Igor!



« Last Edit: September 11, 2019, 07:55:31 PM by Brent Williams »
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Offline Mike Alimov

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Re: Tail aspect ratio and its effects
« Reply #7 on: September 11, 2019, 08:27:52 PM »
https://stunthanger.com/smf/stunt-design/horizontal-tail-aspect-ratio/msg287284/#msg287284

Did you do a search on tail aspect ratio?

Search?  That's so late-20th century, Tim.  My kids are teaching me that the most reliable info is obtained simply by asking a question on social media, which is what StuntHangar is to me.
But seriously, thanks for the link.  No wonder I missed that thread - in 2012 I was too busy being a good parent.
 
So, the discussion went like this: Howard's tests with higher AR tails were, at best, inconclusive, or, in his words, underwhelming; Ted thinks that low AR tails are good because of the induced drag and resulting shift in CP, while Frank W. thinks its because more of the tail area ends up in the propwash; while Randy - who has flown a plane or two in his lifetime - has reported better results with higher AR tails.  Think about it: we have Imitation, long a design gold standard, with a 5.5 AR wing and 4.5 AR tail, and then there's the Yatsenko Classic (I'm too lazy to run math on the curvy Shark) with something like 4.6 AR wing and 5+ AR tail, just the opposite. Both reported to fly extremely well.  Clear as mud!

And Brent - yes, the Max Bee tail is rather large, but seems to work well (for the author, at least).  Here's what he writes in the Max Bee article about the tail size: "Enlarging up to that size [25% of wing area - M.A.] allows the CG to go further and
further back, while extending the tail size over 25% does not give
any further advantage. So I decided to make it a little over 25%,
just to be sure it is not too small."  So he throws some extra tail area in for a good measure and ends up with 32% (!)

And what about Remi Beringer's Gee Bee Sportster with its miniscule flaps, enormous tail arm, and airfoil seen only on vintage combat planes?  Wch Junior title, not too shabby.

If anybody will now tell me that the stunt community has enough knowledge to follow a rigorous, highly scientific process to start from scratch and arrive at an optimal design, I have evidence to the contrary. The designs seem as diverse as the people flying them. I think Phil may have hit the nail with his response, and it reminded me something I was told long, long time ago: stop complaining about your airplane and learn to fly what you have.
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Offline Howard Rush

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Re: Tail aspect ratio and its effects
« Reply #8 on: September 11, 2019, 10:20:01 PM »
Search?  That's so late-20th century, Tim.  ...

Much like facts and data. 

If anybody will now tell me that the stunt community has enough knowledge to follow a rigorous, highly scientific process to start from scratch and arrive at an optimal design, I have evidence to the contrary.

No, you have evidence that the stunt community wouldn't look at it. 
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Online Brent Williams

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Re: Tail aspect ratio and its effects
« Reply #9 on: September 11, 2019, 11:28:12 PM »
David Fitzgeralds De-Tails article was pretty thorough on the topic.  https://stunthanger.com/smf/open-forum/copy-of-the-david-fitzgerald-article-'de-tails'-from-the-marapr-98-stunt-news/msg511851/#msg511851

The record of contest wins from designs with the low aspect ratio tail makes for a compelling design argument. 
The names of the winners of the Walker Cup for the past 30 years would lead one to believe that there is something worthwhile to that design.  Look at what Paul Walker, David Fitzgerald, Ted Fancher, Brett Buck, ect have used.   Those champs don't use things arbitrarily.  If it helps them be consistent and win, they stick with it.  If it proves to be inconsistent and unsuccessful, they abandon it. 

Here is a drawing I put together showing the differences in aspect ratio.  All have the same area.  60/40 split. 
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Online Ken Culbertson

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Re: Tail aspect ratio and its effects
« Reply #10 on: September 12, 2019, 12:52:01 PM »
David Fitzgeralds De-Tails article was pretty thorough on the topic.  https://stunthanger.com/smf/open-forum/copy-of-the-david-fitzgerald-article-'de-tails'-from-the-marapr-98-stunt-news/msg511851/#msg511851

The record of contest wins from designs with the low aspect ratio tail makes for a compelling design argument. 
The names of the winners of the Walker Cup for the past 30 years would lead one to believe that there is something worthwhile to that design.  Look at what Paul Walker, David Fitzgerald, Ted Fancher, Brett Buck, ect have used.   Those champs don't use things arbitrarily.  If it helps them be consistent and win, they stick with it.  If it proves to be inconsistent and unsuccessful, they abandon it. 

Here is a drawing I put together showing the differences in aspect ratio.  All have the same area.  60/40 split.
There are probably only three common element in the designs flown by the Top Fliers worthy of being called a standard - they are straight, trimmed and have a reliable power plant.  Everything else is tuning the plane to the pilot.  I think we spend far too much time time trying to make the plane fly perfect and far too little time making the pilot fly it perfect.  The only ultimate aspect ratio is the one that makes YOU fly better.  You can't totally rely on what the "Top Guys" are doing.  Those guys could probably beat most of us flying a burned out McCoy 35 bolted to a lawn chair.  But, if you have no clue what you want then copying what they do is a good starting point. 

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Online Brett Buck

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Re: Tail aspect ratio and its effects
« Reply #11 on: September 14, 2019, 03:10:30 PM »
There are probably only three common element in the designs flown by the Top Fliers worthy of being called a standard - they are straight, trimmed and have a reliable power plant.  Everything else is tuning the plane to the pilot.  I think we spend far too much time time trying to make the plane fly perfect and far too little time making the pilot fly it perfect.

   On that one I could not disagree more. Under no circumstances should anyone at any level attempt to "practice away"  airplane problems, or at least not when there is any other alternative. Even slightly improving the airplane is usually a much more valuable way to spend your limited time than trying to burn in more flights.  The "get it close enough and then thrash out a hundred flights" plan is not going to work for most people.

     I have seen nearly no evidence that "pilot preference" matters, aside from very small variations. I have flown *many* nationally-competitive airplanes, from all over the place, and they all fly very very similarly, once the trim problems are corrected. There are a few small differences (tail aspect ratio being one of them, engine response being another) but this is far below the normal threshold of anyone but the best pilots. Most "pilot preference" examples turn out to be mistakes that someone accepted or didn't recognize, then they went out and thrashed for flight after flight. At which point, the bad habits formed are misinterpreted as "preference", when they are just mistakes that got compounded by additional mistakes/"work arounds" in piloting.

Of course, if you don't know that there is anything wrong, or don't know what to do about it, that's a problem that you need to overcome.

      I would add  - many or even most airplanes people are flying have multiple egregious problems, and if they were solved, they would improve their scores immensely in a few flights. I have seen people change their venturi by .005" and pick up an immediate 40-50 points. Even slight improvements are worth many, many practice flights.

     Brett

Online Ken Culbertson

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Re: Tail aspect ratio and its effects
« Reply #12 on: September 15, 2019, 09:07:45 AM »
   On that one I could not disagree more. Under no circumstances should anyone at any level attempt to "practice away"  airplane problems, or at least not when there is any other alternative. Even slightly improving the airplane is usually a much more valuable way to spend your limited time than trying to burn in more flights.  The "get it close enough and then thrash out a hundred flights" plan is not going to work for most people.

     I have seen nearly no evidence that "pilot preference" matters, aside from very small variations. I have flown *many* nationally-competitive airplanes, from all over the place, and they all fly very very similarly, once the trim problems are corrected. There are a few small differences (tail aspect ratio being one of them, engine response being another) but this is far below the normal threshold of anyone but the best pilots. Most "pilot preference" examples turn out to be mistakes that someone accepted or didn't recognize, then they went out and thrashed for flight after flight. At which point, the bad habits formed are misinterpreted as "preference", when they are just mistakes that got compounded by additional mistakes/"work arounds" in piloting.

Of course, if you don't know that there is anything wrong, or don't know what to do about it, that's a problem that you need to overcome.

      I would add  - many or even most airplanes people are flying have multiple egregious problems, and if they were solved, they would improve their scores immensely in a few flights. I have seen people change their venturi by .005" and pick up an immediate 40-50 points. Even slight improvements are worth many, many practice flights.

     Brett
Brett, there is nothing in your response that I would disagree with were I in the same flying environment you are in but I am not.  I have been flying competitive stunt since I was 14 years old and except for one period surrounding 1980 and a few fliers I know now, I have had no one to turn to that knew more about trimming than I did and I didn't know squat.  Another thing that we just don't do much of is flying other people's planes.  I am not sure why, we just don't. 

I was out of the sport from the end of the Fox 35 era till a couple of years ago. In my case that has means that I am flying .60 sized ship that I have built not having a clue what a properly trimmed ship of this size and power is supposed to feel like and I am not alone.

Lastly, I am lucky here to get in 8 flights a week and that is only if Mother Nature cooperates.  In those 8 flights you have to get wings level, lap time to your and the planes liking, c/g set and turn ratio's balanced, leadouts set and that is just so you can start the actual trimming and all of that is supposed to be done without violating the "one change at a time" "rule".  Before you know it's contest time and you are still trimming.

Let me end this by saying that you are ABSOLUTELY RIGHT in everything you said, it just won't work in the environment I fly in and I would venture a guess that a lot of us (most of which do not frequent this forum) are in the same boat.

Keep it up.  I learn a lot when you take me to the woodshed.

Ken
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Offline Ted Fancher

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Re: Tail aspect ratio and its effects
« Reply #13 on: October 11, 2019, 03:15:38 PM »
"snip"

I would expect the higher aspect ratio tail to be more effective as a lifting surface, thus probably requiring less deflection - thus less drag in corners, not a bad thing, eh?

Missed this one back when it was active.

Mike's comment in the snip above is pretty much the best answer to his question of the thread. 

The effects of aspect ratio are pretty much the same regardless of where the surface involved is attached to the airplane.  The most important part of selecting the "best" for your purpose aspect ratio is that the resulting delivery of lift per unit of angle of attack best suits the task of the airplane in question.

Aspect ratio can best be understood by checking out the full scale airplanes designed for specific purposes.  Mike's description in the "snip" above is as good a one as we require.  High aspect ratios of a given area will produce a "given" amount of lift at a lower angle of attack (or in the case of tail-planes, elevator deflection) and produce less induced drag (drag that is the product of the lift delivered) than lower aspect ratios while doing so.

This is why you see slow flying sailplanes with very high aspect ratios (and no "motor/engine" to overcome additional drag) and high speed jet fighters with very low aspect ratios (with ton's of thrust to overcome the additional drag and still maintain those high speeds).

When speaking of "tails" for our stunt ships one needs to keep those factors clearly in mind.  The amount of tail lift to provide the desired corners will be ~more or less the same whichever aspect ratio you select.  The difference will be how much deflection is necessary to achieve the necessary "moment" about the CG to provide the desired rate of pitch change of the ship.

If you have lightning reflexes and the ability to build a very high aspect ratio stab/elevator at adequate rigidity (to prevent flexing) the amount of deflection necessary to achieve the desired pitch change will reduce dramatically the higher the AR gets.  In addition, the pilot input force necessary to get that lift increase at small deflection will be "much" less the higher the aspect ratio.  These combined factors less force required at lesser deflection to obtain the necessary lift for the desired corner will rapidly get to the point that the airplane track in pitch (maneuvering) will become very difficult to control...more lift at less deflection at some early point will require less and less line spacing at the handle further lessening the pilot "muscle" necessary to produce the desired pitch rate/corner size let alone fly smooth consistent round loops!!

The opposite--very low aspect ratios--will require much greater deflection and produce much more drag to provide the same lift to obtain the desired corner...and will quickly bring the Netzeband wall into play (not enough line tension to allow the necessary deflection to to obtain the desired/necessary aircraft pitch rate for the trick.  (more discussion available if some aren't able to "think" the reverse of the effects of high aspect ratios).

Finding the best balance between the two options (different people might well have different preferences on aircraft response rate) is one of the important "fine tuning" factors in producing a stunt ship that responds as desired using the control inputs (both amount of deflection and [pilot] energy) to achieve it.

What successful designers have done over many years (even if they didn't realize it) when developing a career's worth of design refinements is experiment with the endless variety of options obtainable to find the ideal (for them but generally satisfactory for most) combination of these factors (and, IMPORTANTLY, the total tail area as a percentage of wing area and CG location) best suited to take advantage of those factors.

My designs starting with the Imitation/Excitation were a foray into this exact subject matter and several other design factors, wing area/aspect ratio/flap area/chord percentage, etc.  David fitzgerald's Stunt News article "D'Tails" several years back also includes excellent discussions of the subject matter.

These factors are an important part, for instance, of my discussion of design parameters touched on in my opening post of the At The Handle Forum; "Some fresh thoughts on “Where/How to look while flying".

Once again, sorry for the length.  Once I get started it seems my fingers take on a life of their own1

Ted


Offline Chuck_Smith

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Re: Tail aspect ratio and its effects
« Reply #14 on: November 17, 2019, 06:50:38 AM »
Some things you need to understand about aspect ratio.

The induced drag is a function of Aspect Ratio (AR) and that has a direct bearing on tail aspect ratios.

What is induced drag? The short answer is it's how air at the tip of a flying surface creates a vortex that puts a component of flow to the incoming air pointing away from the direction of lift.

For a wing this means that the geometric angle of attack will be higher than the actual angle of attack to the oncoming air.

This is visible if you look for it in airplanes. A sailplane with it's high AR will stall at a low angle to the horizon and land pretty "flat" whereas a low aspect ratio planform will stall at an almost ridiculously high Angle of Attack.

OK, that was the short version and it's still rather long winded but here's why it's important to understand:

If the tail stalls before the wing, that's not-so-good wrt controllability. So aircraft design 101 is that you always have a lower aspect ratio on the tail than the wing.

For stunt - probably doesn't mean jack. We use such obscene deflections and make such tight turns that "normal" doesn't apply. I had some pretty high tail aspect ratios in the day because we were flying bigger and bigger ships but didn't have the power we do today. I used Busso's Kestrel as a starting point. My thought process was the higher AR tail would have less drag in the corners. Back in the ST.46 days you had to keep it from bogging in the corners.

This was also evident in some of the late 70's combat ships. Super high AR's with triple booms and a wide skinny tail where in vogue for a while. Winders, Spectrums, etc.

Today - who knows where the limits are? Adequate power is a given so I don't feel the need for a high AR tail, but I've not seen anything that shows me one tail is better than the next. I use the TLAR method and a little math, i.e., I go for what's aesthetically pleasing and then math out the hing line and area.

My experience has been that guy with the straightest airplane, with reliable power and the most practice and experience usually gets the highest score regardless of his tail aspect ratio.

YMMV, All opposing viewpoints welcomed.


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Offline Howard Rush

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Re: Tail aspect ratio and its effects
« Reply #15 on: November 17, 2019, 08:54:23 PM »
My experience has been that guy with the straightest airplane, with reliable power and the most practice and experience usually gets the highest score regardless of his tail aspect ratio.

The straightest guy with reliable airplane and the most power.  Yep, sounds like the Jive Combat Team.
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Offline Chuck_Smith

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Re: Tail aspect ratio and its effects
« Reply #16 on: November 21, 2019, 06:43:42 PM »
But Howard,

I've been from here to there in aerodynamics and to this day, the most beautiful and perhaps most aerodynamically perfect elevator was on the Nemesis.

I tip my hat to it's designer.

Would love to learn the history of it's genesis.

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Offline Shorts,David

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Re: Tail aspect ratio and its effects
« Reply #17 on: November 26, 2019, 04:54:12 PM »
Brett, there is nothing in your response that I would disagree with were I in the same flying environment you are in but I am not.  I have been flying competitive stunt since I was 14 years old and except for one period surrounding 1980 and a few fliers I know now, I have had no one to turn to that knew more about trimming than I did and I didn't know squat.  Another thing that we just don't do much of is flying other people's planes.  I am not sure why, we just don't. 

I was out of the sport from the end of the Fox 35 era till a couple of years ago. In my case that has means that I am flying .60 sized ship that I have built not having a clue what a properly trimmed ship of this size and power is supposed to feel like and I am not alone.
Keep it up.  I learn a lot when you take me to the woodshed.

Ken

Hi Ken,

I want to jump in and say that June 2018 we were scheduled to have a little contest and a trimming session out at the field. Brett Buck, Ted Fancher, and on Sunday David Fitzgerald were all going to be helping out. Anyhow, it was over a hundred degrees and very windy and we all wimped out and Jim Aron got us a conference room at the local hotel.

We were taken to the WOODSHED. Brett and Ted spent several hours in a room of thirty guys talking about design and flying. I turned to my 82 year old dad who has been flying, directing, and selling the stuff for decades. I said, "So, did you know all of this already?" Thinking my wizened father surely did. And he was dumbfounded. "I didn't know any of this!" He gasped.

I still don't know any of this, which is why I love the articles and discussions. Thanks for asking the questions.

I will add, I flew the Hi Johnson Panther (the second generation one) for a while and it snapped flat out of the rounds. I loved it. Now I'm flying a Chizler and it just sort of levels out...at some point. Whatever the aspect ratio, if it doesn't have a crisp level out, the plane doesn't work. (is that safe for a newbie to say?) Is that all a result of the AR?


David

Online Brett Buck

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Re: Tail aspect ratio and its effects
« Reply #18 on: November 26, 2019, 07:18:47 PM »
. Anyhow, it was over a hundred degrees and very windy and we all wimped out and Jim Aron got us a conference room at the local hotel.

   And, in the spirit of full disclosure, David and I were at the head of the line to wimp out!  While we probably could have gotten through patterns flying our own airplanes, with a lot of fudging, we were not exactly chomping at the bit to fly everyone's unfamiliar, and in many cases, trim- and power-challenged airplanes in these conditions. David took the additional step of leaving entirely!

     Brett

Offline Mark wood

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Re: Tail aspect ratio and its effects
« Reply #19 on: February 29, 2020, 10:32:48 PM »
The new guy in the bunch reads a lot of back and forth about a dead horse. Who killed it by the way? The trouble with much of modeling is a lack of systematic testing. While all of what I read is mostly subjective some is aerodynamically correct but off base in terms a stabilizing element in an oscillatory system. AS far as I can see the horse isn't even really hurt, it's just laying there faking it. While the aspect ratio does a couple of things desirable for a wing which basically increases lift and reduces drag, it does something else which no one really thinks about which is how the lift is in fact increased. Or rather what the fall out of the increased lift is. When the lift is increased via aspect ratio the lift slope also changes, Cl/alpha. The change in lift slope on a wing has some minor impact but when the tail is concerned it can have an impact. Think of it this way, if you could tune the gain of the lift in the tail you could change the damping it does. Well, that is basically what A/R does in this coupling with the wing. The trouble is there is a meat servo in the control loop and that servo inputs another Flap/chord lift coupling which puts another gain loop in the equation. Preferably a positive one.

The impact with the pilot in the loop is very tough to quantify the impact of changing just the aspect ratio of the tail-plane in testing and can be extremely subjective. Remove the pilot from the loop and the result of increasing the A/R of a tail plane would be increased damping for a given area / TVh.  Likewise reducing the A/R would decrease the damping. The trouble is, with the meat servo in the loop testing, is that the impact of A/R  is overwhelmed by the Flap/Chord CL gain driven by the meat servo . With a suitably damped stick free system and adequate Clf/c gain the resulting trajectory can be driven provided the resulting Clw does not reach a critical value. On exit the question is one of whether the stick free oscillation damps rapidly enough for the trajectory to be what he meat servo desired. If that is satisfied, what does it really matter what the tailplane A/R is as long as it correctly satisfies the ultimate coolness factor? Badassedness matters in aircraft design after all....
 
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Re: Tail aspect ratio and its effects
« Reply #20 on: April 26, 2020, 10:55:56 AM »
   Lots of information here. This doesn't look like the horse has been turned to dust quite yet for me an example of a dead horse beating is discussions of what oil to put in some of these big Japanese Vee Twin motorcycle engines.  That subject & opinions are endless.
   Opinions aside this is a subject I've been looking for.  With a plane that has a removable stab I wonder  what the effects are a high aspect & low aspect ratio plane. An example is take an Impact &  try 3 vastly different stabs & observe the results.
    Yes, my next plane will have a removable stab for several reasons.
      John L.


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