Oddly the Carenado's aircraft fly best with the sliders all the way to the left.

 

Geof, I've read somewhere that some of the Carenados use Artificial Stability through PM. I have done that myself to fine tune the Baron 58 and the C90 so that they stopped showing almost any bank due to torque effects, but that's cheating ;-)

 

That's also why Morten's Piper is "clean" from those bank due to torque effects....

 

For me it's a way to tweak, but certainly not the one I would like to have to use... The ailerons will automatically deflect whenever a rolling moment is present, being it due to torque effects or any other source (probably fuel imbalance as well...). This is no good for me :-( although it works....

Near the edge of the envelope, for instance just before reaching the critical AoA, you will also start to see weird aileron movements not connected to your direct inputs... Not nice....

Jcomm-I can get these aircraft to a somewhat positive stable trimable state by sliding the stability sliders full right ( though still needs rudder/aileron trim which is not right) but we have been told over and over that that is a "cheat" …

 

Just to clarify: You are talking about those settings in the joystick menu or modifications to stability you do in plane maker? Because I can't see that those in the joysticks menu would be considered a cheat. Plane maker due to the effects jcomm named: yes, not perfect. But the joystick stuff is there to assist you in getting comfortable with your hardware first and foremost. There are very sensitive rudder pedals and the opposite etc.

 

My settings are not full left ("most realism"), but around 10-25% depending on the axis.

Sensitivity should be the setting we change when our controller is making much too rough inputs, not artificial stability, this last one will create a false stability to the Flight Model that shouldn't be there, the developer made the airplane using the tools available to be as realistic as possible, including stability, so there's nothing for us end users to change there, the correct stability coefficients should be built in the FM, not left for the user to adjust to it's liking. You can't change that as you fly a real plane.

 

If that's not how X-Plane works, then I think they should change the name of this option, because that's what seems to be it's function.

Sure, stability (I'll quote from the manual to make that clear to everyone.). I understand what you say but keep a practical approach to this.

 

If used wisely, I don't consider it a cheat. As I said: I'm not at 100% right either (my sensitivity aka "control response" is pretty wild in order to fit my hardware even better; we deal with a combination of a variety of settings here), but here's the thing: Different planes from different developers are laid out differently in Plane Maker. Examples were named. Do I want to change my joystick settings everytime I fly? No. So what do I do? I find a setting that suits the variety of aircraft that I fly (in my case: no heavies, mostly light plane, maximum twin props). With those, "full realism" is not always the "real" realism (often too twitchy in X-Plane), as has been mentioned by various people and their experience. So, if I minimally correct for that, I don't call it a cheat.

 

Manual, page 34

 

In the upper left portion of the Nullzone screen is another set of sliders, labeled “stability augmentation.” These control X-Plane’s stability augmentation by damping the predicted forces acting on the aircraft’s flight control surfaces. If these sliders are all the way to the left, then there is no stability augmentation of the aircraft. As the sliders are moved to the right, X-Plane will automatically add some stability augmentation to the aircraft, adding some elevator input to level the nose, some aileron input to minimize the roll rate, and some rudder input to counter any aircraft yaw rates. In other words, the simulator will try to make the plane easier to fly by adding control inputs for the user. The downside, of course, is that as X-Plane adds stability, the aircraft becomes less responsive (and less realistic).

(IMPORTANT Remark at the end of this post!!!)

 

I was talking about the section on the attached screen ... Expert / Artificial Stability / Art Stab, namely the lines concerning roll.

 

You can set a high speed and a low speed regime for your Art Stab (in this case just in roll) to adapt depending on the range you're in.

 

Say, for the Baron 58, you set the low speed starting at Vmc, then for speeds above this you can "activate" the Art Stab so that you get a desired target deg roll / sec, through an additional fraction deflection per degree per second difference.

 

You can play with this values until you're satisfied with the roll stability of the prop aircraft regarding the torque roll. If you know the exact max roll rate of a Baron58, then you can use it in the target deg/sec roll rate.

 

Let's say the Vmc is 84KIAS, then, set High Speed System to 0.084. Let's admit the target roll rate is 60 deg/sec. In the attached screen you can see that I chose: roll=060; fraction deflection=0.12 and HIGH-SPEED=0.084. The Low speed automatically forces it's start at 0.083, but for values bellow Vmc I didn't activate the Art Stab.

 

Go flying after saving the "airfile" under FILE - Save [CTRL-s]... Don't forget to save the original folder of the Baron58 just in case ;-)...

 

Ah! Beware that the default Baron 58 already includes an aileron trim tab setting of 0.030 (positive = right), so it is trimmed to counter torque roll at cruise. This can be lowered, or even eliminated once you start using the Art Stab tweak... but even better - play with it! The trim tabs are under Standard - Control Geometry - Trim&Speed...

 

Then, for realistic yaw effects at takeoff / high power climb (less noticeable on a twin anyhow...) one may end up irrealistically having to set an engine cant to the left (exactly the opposite of what should be done in RL...)

 

Last but not least, make sure that at least the ROLL sliders for artificial stability and joystick sensitivity under the Joystick menu are all the way to the LEFT, because the stability augmentation is already programmed into the flight model file itself!!!

 

 

 

Remark: I've long been using this sort of tweak with most prop aircraft, either default or payware, but I just arrived there because I was carefully driven buy Goran. Goran pointed me what could be done with this section of Plane Maker, although he doesn't use it at all, for the sake of realism, in his own aircraft (at least the Sundowner and the Dc3). Instead he invested seriously on good RoGs, and most probably airfoil data adjustments as well... Goran's airplanes (at least those I use) do not cheat!

Hmmm.I have found I have had to use stability sliders for all xplane aircraft except the Carenado that by my understanding does use the method you have highlighted above.

 

In any case I am not sure why adding stability to an unstable airfoil would be a cheat but it is nice to see that it might be attainable!

 

Also as a note-I didn't seem to have trouble with the Carenado Bonanza rolling so much until 64 bit. I'd retest on 32 but I can't get it to run without getting an out of memory error.

I'm curious about GoranM`s aircrafts made without any use of artificial stability. I read he's planning on releasing an update for his Beechcraft Sundowner. That's the only aircraft he designed that I can relate too, the other twins is just too far out of my league.

 

Thanks Jcomm for the nice tutorial, will try that someday!

(IMPORTANT Remark at the end of this post!!!)

 

I'll pass on the discussion about the artificial stability for now, but I have a riddle that you may help me solve, jcomm :smile:

 

On www.x-plane.org there are 2 RL pilots of Rutan aircrafts, one has a VariEze and the other a Cozy. They both say that the roll effect due to torque is very exaggerated in X-Plane, while in RL it is much less, if practically non-existent.

 

http://forums.x-plan...?showtopic=7777

http://forums.x-plan...showtopic=51251

http://forums.x-plan...showtopic=55518

 

Now here's the riddle for you: as you probably know, both the VariEze and the Cozy have a canard, push-propeller configuration. So, there is absolutely _nothing_ in the slipstream of the propeller. What is then compensating the varying torque of the propeller in flight?

 

The only possible explanation I've found is by having a canted propeller, that induces a yaw angle and therefore a secondary roll moment opposing the roll moment caused by engine torque. I don't know if VariEze's actually have a canted engine though.

 

www.airliners.net/photo/Patrouille-REVA/Rutan-33-VariEze/0907721/L/&sid=78736ef9298fb0acda6f3cd2d66bf3a6

www.airliners.net/photo/Rutan-33-VariEze/1522055/L/&sid=78736ef9298fb0acda6f3cd2d66bf3a6

 

 

This is the reason why I went to X-Plane...

 

The effects of sinking and floating due to poor power management are modeled much better in X-Plane and you can get yourself into trouble a bit easier in X-Plane. I love FSX but the flight model of "Set it and forget it" got old and not realistic over time.

 

I've never looked back after converting my sim to X-Plane. Not saying that XP doesn't have it's own issues. (Oh it does!) but the flight modeling is better in my opinion.

Perhaps the answer is here Marco-Canted winglets, dihedral and fake Hershey bar...

http://www.homebuiltairplanes.com/forums/aircraft-design-aerodynamics-new-technology/6501-tip-stall-highly-tapered-wings-4.html

Poor power management-who does that rw?

 

<edit> I did meet someone once in my 25 years of flying who did accomplish this. I was at a fuel stop somewhere in West Va, Us and there was a picture of a crashed p51 on the side of the runway. My flying partner and I were admiring the photo and someone approached us and said " yes I was the dummy who did that". Turned out he bought the p 51, got no training, took it to the runway, gave it full throttle and went promptly off the side. That is the one power management problem I've ever seen.

In any case I am not sure why adding stability to an unstable airfoil would be a cheat but it is nice to see that it might be attainable!

 

In principle I agree, it shouldn't matter how you get there, if the end result is accurate. The way Blade Element theory though has been portrayed by Austin, it seems to go against it, if artificial stability is necessary to achieve it. From a practical standpoint it doesn't matter!!!

This is the reason why I went to X-Plane...

 

The effects of sinking and floating due to poor power management are modeled much better in X-Plane and you can get yourself into trouble a bit easier in X-Plane. I love FSX but the flight model of "Set it and forget it" got old and not realistic over time.

 

I've never looked back after converting my sim to X-Plane. Not saying that XP doesn't have it's own issues. (Oh it does!) but the flight modeling is better in my opinion.

 

You can get yourself into trouble with either sim. I guess I just don't use those "set & forget" FSX models, any more, than I'd use a poor X-Plane model.

I actually do, have some very nice 3rd party FSX models, that do a very credible job or engine/power management during the landing phase. This is why I don't like these very generalized & simplistic assumptions, regarding flight dynamics. Of course, anytime I (repetitively) mention this.................is does seem to tick off a few readers here & there.

 

L.Adamson

In principle I agree, it shouldn't matter how you get there, if the end result is accurate. The way Blade Element theory though has been portrayed by Austin, it seems to go against it, if artificial stability is necessary to achieve it. From a practical standpoint it doesn't matter!!!

 

I'll chime in... For a lot of people, especially real pilots, what it counts is the final result, not how one gets there: it doesn't matter if one uses all the possible "tricks" to get realistic handling and feeling, the final result is the only thing that matters. in LAdamson words, there are no real air molecules inside the simulated flight model, it's all a "trick" after all, and that is true.

That is not only absolutely legitimate, but also absolutely understandable.

 

On the other hand, I'll try to explain why those who look at it from a different point of view, an "engineering" point of view (like me, jcomm, tkyler, GoranM) are more wary and sometimes use words like "cheat" and the alikes.

 

The fact is, the various tweaks we're talking about, are fundamentally workarounds devised to solve the imperfections and limits of the base flight model. The problem lies in the fact that with those workarounds, one can easily introduce unwanted and possibly unpredictable consequences.

 

This problem is much more relevant in X-Plane than e.g. in FSX due to the differences in the flight model of the two. In FSX the table based approach gives a much more "isolated" control over the various characteristics of the flight model: if I "cheat" on one value, the consequences on the overall flight model can be probably more easily evaluated.

 

On the other hand, in X-Plane the flight model is significantly more "organic": a tweak has easily consequences on a lot of other aspects of the flight model. This is also the reason why it's sometimes harder to tweak an X-Plane model to perfect specs and handling, and why it is really important that the base flight model is as accurate as possible.

 

Other than that, I think (at least for me, maybe also for tkyler, jcomm, etc.?) it does not make sense from a "philosophical" engineering point of view, to have a base flight model that is for the most part predictive, and then bend it so much as to take away from it every predictive meaning.

 

As already said, pilots only care for the final result and they're absolutely right in this! :smile: Just wanted to explain the "other" point of view on the issue.

 

Marco

Marco-you are such a breath of fresh air and I hope I can buy you a beer sometime-either in the U S or Italia.

 

I had to do the aerodynamic thing when I got my FAA ground instructor rating/cfi class but since that was 10 years ago get rusty .

 

However-I have seen this on the other platform. I was asked to beta test a fsx Baron and was asked about the spin characteristics. Had to say I had never spun a Baron and in fact Beech stopped trying in the 1960's cause all their pilots died when they tried because they went into flat spins. I would never do one because I don't want to die and really dont care about simming ths since it isn't realistic.

 

I owned a Baron for 7 years-99% of the time I took off, leveled off , and landed. True I had some nasty icing incidents,some mechanical, and always interesting weather. The other 1% -engine out training.

 

So is it important that the fm can simulate stuff you will never come across, or is it important that it simulates what you experience 99.9% of the time-stability being a big part of it.

 

Therefore-if the Baron is unstable-not realistic like 99% of the time. If the Baron rolls in level cruise flight-not what you experience 100% of the time.

 

If you put it in a flat spin-perhaps interesting to te engineer-but would never happen rw unless you wish to die. If you suddenly chop the power and the aircraft rolls-perhaps interesting to te engineer-but as a real pilot would never have done this-perhaps useless to rw operations?If I had my 2 flying partners probably would ave kicked me out f the club-after you spend 90,000 for new engines such technique would get you banned.

 

Is ths sim for academia or for rw operations?

Geofa you are absolutely right! But maybe you misunderstood me :smile: I'm infact advocating for the most possible realistic flight model, first and more importantly in the normal flight envelope! I would not consider acceptable an aircraft model with no "cheats" but unrealistic handling.

 

But the way I see it, and the point of my previous post, is: if the _only_ way to obtain this is to bend "too much" the flight model of X-Plane, then for me this is a problem that must be corrected in the X-Plane flight model, for those specific aspects that requires "cheats".

 

Example: if the only way to obtain a realistic handling Bonanza is using artificial stability, then for me, looking from an engineering point of view, this is a problem with X-Plane flight model, even if you as a pilot may be totally satisfied with it. I guess it comes to one of those irreducible differences in the point of views of a pilot and an engineer.

 

P.S. I think I never drank an American Beer, but I'd like to... I only know Budweiser though :lol: