I am doubtful that roll is non-existent as Geofa suggests that it is.

 

I go along with Geofa.

 

I'm including a pic. Notice that the aileron & aileron trim tab are very close to neutral..........if not actually neutral. This is in cruise flight (RV6). The wings on this plane are exactly the same for incidence. Engine is canted to the right, and a fixed trim tab is used on the rudder. Torque at low air speed, and full power is very noticable............however, it won't roll the plane on it's back, as a P-51 Mustang can do.

There is a countering force as you see here, but what I get from this conversation is its not strong enough in x-plane and the roll is too much....

 

Tom, when I investigated further I also arrived to that exact conclusion. Your picture shows the modelling of slpistream in X-Plane10, already very good, but we can even see , looking from 6 o'clock, when in flight, that there is a stronger resultant on the inner portion of the left wing, usually nearer to the fuselage (a longer green vector).

 

Many posts ago I even posted a picture to show that indeed this could be there exactly because X-Plane models that effect of the asymmetric hit of the slipstream on the under side of the left wing, thus pushing it up, and giving that resultant that is visible in X-Plane10 on almost all prop aircraft. I don't recall excatly, but I believe I also experimented with the Piaggio Avanti and it was not there, which seems correct given that the slipstream will not hit either wing...

 

There is allways hope, and X-Plane10 is still an ongoing project, and the team behind it is working hard to make it better (your recent upgrade to the C90 is an excellent example!) and some tallented 3pds keep releasing excellent add-ons too.

 

Austin will do something about it, I am sure. After all, he already changed the turbulence effects twice (honestly I thought they were already good with the first modification in XP10.10...).

 

:-)

 

I'm including a pic.

 

Larry, thx for the pic! With those clouds I see in the far horizon, near the mountain range, I'd rather be flying a glider there :-)

Jan, I don't have an issue with yaw in the Baron, don't see or feel any at all. It's the constant roll, or a better way to decsribe it is "teetering" that just doesn't seem right.

 

Image yourself standing on a platform, that's sitting on a cylinder and your trying to balance yourself but you just can't. You keep going left to right, right to left, and so on. Well that's the way the Baron flies, constant rolling and no amount of trim can stop it.

 

 

I am not sure if you even looked at my video... It clearly shows that there is no constant rolling or teetering - the bank is constant at pretty much wings level and even if upset, it returns to that.

 

If I show you a movie of an apple falling to the ground in my garden, and you keep claiming that in your garden they fall towards the sky then I guess we just have different realities and must accept that.

 

Jan

 

As the topic slowly shifts towards the effects of engine torque in this subject, I feel the need to add my 2 ct :-)

 

I have also never conciously noticed the effect of torque changing in the various propeller airplanes I flew. Even in the Piper Cheyenne with it´s strong engines there was basically no need for a different trim setting or aileron input with varying engine power.

 

Now I can understand how clever design would try to "null out" any torque effects in the typical cruise flight regime. But even if yanking the power to idle, there was no resultant roll that I can remember.

 

When first flying X-Planes models I was surprised by the strong roll in some of the twins. When thinking about the physics behind the scene, it would appear that there should be some roll, as the torque needs to be countered.

 

I just don´t know why the real planes barely exhibit that effect...

 

Jan

I am not sure if you even looked at my video... It clearly shows that there is no constant rolling or teetering - the bank is constant at pretty much wings level and even if upset, it returns to that.

 

No, I didn't look at your video. I can tell you from my own XPX experience there "is" a constant rolling and teetering in the default Baron, but not the Duchess (not nearly as exaggerated). Why is that, that's all I want to know?

 

I can pretty much guarantee you that Goran has done "something" to remedy this issue with his addons, but won't speak up for obvious reasons, fair enough. His aircraft definitely handles way better than the default, there must be a reason. If I'm totally wrong, Goran can let me know and I will crawl into a hole and be quiet.

 

I guess we will just have to agree to disagree, although it's seems there are a few more here that agree that there is an issue. I guess they don't know what their talking about. ^_^

I just don´t know why the real planes barely exhibit that effect...

 

Jan, please see my post above :-) - http://forum.avsim.n...25#entry2571254

 

Dynamic pressure should also be more than sufficient to overcome the roll moments at cruise speeds, I forgot about that one on my post...

Then, just as Tom suggested, X-Plane appears to model the effects of asymmetric slipstream I talk about in the above post, but probably either this are insuficient, or torque is overdone....(?)

I read your post, jcomm, and think it probably offers a good explanation why we have this effect in X-Plane that we don´t see in reality.

 

Of course there is always the possibility of a simple "typo" somewhere in the code, too

 

For me it´s just amazing that the effect of torque cancels out so reliably throughout the whole flight regime - from takeoff, with it´s high torque and low airspeed over cruise descents with low torque and high airspeeds to initial approach with low airspeed and low torque... Barely any roll changes, as a matter of fact I don´t even remember where the aileron trim is in the Cheyenne.

 

We need an aircraft engineer or professor of aerodynamics in here!

 

Jan

 

No, I didn't look at your video.

 

I guess then a fruitful discussion is out of the question and I consider this resolved.

 

Thanks and have a great day.

I love these challenges! Here is a video of the Baron in straight and level flight - default Baron, no plane-maker tweaks.

 

Please not that I did adjust the trimsetting with the trim-wheel controls in the 3D cockpit - the joystick buttons (or even the keyboard) will only get you so close.

 

 

http://youtu.be/ZBY85cbdwSI

 

I find the Baron to be fairly stable around all axis, if you put in a 10 degree bank when trimmed like this it will right itself without further input.

 

There are other default aircraft that are not as stable, unfortunately.

 

The correct technique for trimming is like this: Level wings and stop the yawing tendency with rudder trim. Now use aileron trim to make the plane keep wings-level.

 

After that you can experiment with the new "neutral" bank of the plane - usually it will settle steady at a few degrees left or right. Now use tiny inputs of the trim wheel in the cockpit to adjust.

 

Jan

 

There is the whole problem Jan. in my Baron I never ever had to touch aileron trim-ever and the only time I touched rudder trim was went doing cut engines.

Barely any roll changes, as a matter of fact I don´t even remember where the aileron trim is in the Cheyenne

 

Yep, and twins present less problems also because of the higher roll inertia due to the wider distribution of weight accross the pitch axis (those two heavy engines...)

I read your post, jcomm, and think it probably offers a good explanation why we have this effect in X-Plane that we don´t see in reality.

 

Of course there is always the possibility of a simple "typo" somewhere in the code, too

 

For me it´s just amazing that the effect of torque cancels out so reliably throughout the whole flight regime - from takeoff, with it´s high torque and low airspeed over cruise descents with low torque and high airspeeds to initial approach with low airspeed and low torque... Barely any roll changes, as a matter of fact I don´t even remember where the aileron trim is in the Cheyenne.

 

We need an aircraft engineer or professor of aerodynamics in here!

 

Jan

 

 

 

I guess then a fruitful discussion is out of the question and I consider this resolved.

 

Thanks and have a great day.

 

Jan, I don't need to watch "your" video to try to convince myself that what I see with my own eyes doesn't exist. It's certainly not an illusion. The issue is far from resolved and needs to be fixed for those that wish to fly the default aircraft. Mind you, the default aircraft in Xplane have been hammered enough over the years, wonder why, I was just wondering if they could be better. We as a group will decide when something is resolved, not you <_< , and it appears from this discussion that nothing is resolved and probably never will be. You can decide not to continue in the discussion if you feel there's not an issue and it's been resolved, some of us beg to differ. Thank god there are alternatives.

 

You have a nice day as well...a wee bit of sarcasm. :mellow:

 

Geof, why bother, you don't know what your talking about......

 

Edit: Now, I will repeat myself, and please give an explanation. The Duchess flies perfectly fine even with a good crosswind, give her a bit of aileron trim and she sits there. Every once in a while give her a nudge on the yoke and she sits back where you trimmed her. The Baron does not exhibit the same behavior. Why does the Baron not fly more like the Duchess, and according to the real pilots around here, more like the real thing. Are they all wrong, and your the only one that knows what your talking about?

........... which raises the question, how can flight schools and simulator companies use XP for training if the aircraft flight dynamics are unrealistic. Do they have something we don't?

 

Simulators are more for teaching procedures than flight dynamics, even commercial sims costing millions of dollars.

There is the whole problem Jan. in my Baron I never ever had to touch aileron trim-ever and the only time I touched rudder trim was went doing cut engines.

 

I agree with you, I don´t think I ever used aileron trim in a prop, either. But we must be careful not to mix too many issues running in this thread up.

 

1.) Can airplane in XP10 be trimmed to fly reasonably straight and level hands-off? I think so.

 

2.) Is the torque-induced roll in XP10 realistic in quantity? I think not.

 

I think we also agree that flying in any simulator is still quite different from flying the real thing, for a myriad of reasons. Just having your hands and feet on a real yoke and rudders is so different from the small and flimsy joysticks, and the lack of sensory feedback makes staring at the horizon all the time much more important when in a computer simulation.

 

So if the question is: "Does flying a plane in XP10 feel exactly like flying the real thing?" Then the answer would have to be a no.

 

Does it get close? Closer than any other simulator I have tried, except for the "real" simulators.

 

Jan

and the lack of sensory feedback makes staring at the horizon all the time much more important when in a computer simulation.

 

This is the point I'm trying to make. In the Baron the horizon is constantly on the move (teetering), I can't stop it for even 10 seconds, back and forth, back and forth. While in the Duchess, the horizon moves, but nowhere near the same rate, their both twins. Why is that, and what needs to be done to the default aircraft so they will "fly" more like the Duchess, which to me seems more life like. Sorry Goran, if the defaults flew like yours then I guess you wouldn't sell any aircraft, but you get my point, I hope.

There is the whole problem Jan. in my Baron I never ever had to touch aileron trim-ever and the only time I touched rudder trim was went doing cut engines.

 

Not that I'm an expert in these things, but I think TomK made a very good point when he said that there has to be something in the real aircraft that is counteracting these forces and which, for whatever reason, is not being modeled correctly in X-Plane 10. Figuring out what that "something" is would go a long ways towards reconciling the roll issue.

I'd like to jump in once more since Tkyler is very honest about having a discussion about improving the default Baron's flight model.

 

I'd like to throw in also that my single engine Bonanza I owned 11 years did not have rudder trim and I only used the aileron trim once-because the plane was a little misrigged I had it permanently a little to the left. Never touched it after that.

 

In addition to this roll issue is the general control response issue and momentum.

 

I had perhaps a unique opportunity because I simmed for 8 years in the early 80's before I took my first flight. I still remember my first flight in a piper archer feeling a little disappointed After the pilot trimmed the plane well, he asked me to fly it. After flying a sim, I honestly didn't like the way the plane felt like it was fighting me when I tried to change the direction or pitch of flight. There is that 1/2 second of feel depending on the aircraft where it resists a change to trim,it doesn't just react instantly like attached with a rubber band.

 

So on the Baron-the roll is not only way too fast (and the pitch), but there is no "feeling" of this factor.

I used to think it was just a limitation of xplane-until I tried Carenado's Bonanza and found the control response exactly what I would expect.

 

There is also the issue of momentum-when you change a power setting for instance there is again that second of the plane reacting in disbelief before it reacts-it doesn't happen instantaneously. When I became more experienced this became a necessary skill getting a Bonanza down and stopped on an extremely short runway with 75 ft. trees on either end. You would come in 5 feet above the trees, and with about 20 ft. of trees left chop the engine. In the second or two for the plane to react and start to slow down you would now be just clear of the trees where you could point the nose down and get it right on the end and land at minimum airspeed.

 

For me there is a simple answer-and to other things about xplane that could be improved. I really like the sim, and I do think it is the future. I also like to think with user input and developers listening it makes the sim even more powerful. But instead of debating it, why not experience it where it works, and copy?

 

So-a simple answer-know your competition! If you want to know what a Bonanza (and the Baron is the same except a little heavier) controls like-get the Carenado Bonanza-see how it reacts with no stability adjustments/joystick adjustments. They got it right! The feel of momentum, and the wonderful control response of a Bonanza is all there to marvel at.

 

If you want to know how a Baron flies-try (shock) the Milvitz B55 on fsx ( I personally don't care for the Carenado version in fsx-yes -the landings feel like on rails-we can ignore that phase). But again, see how the controls react, the feeling of "heavyness" and "momentum", along with strict adherence to "numbers" and excellent single engine simulation.

 

Take a look at this competition-then improve it and make it better! I vote the same for all the other aspects of xplane that are constantly debated-and if it can't be made better in house-recruit 3rd party developers more aggressively to produce for it. I got notice recently that Laminar has hired a pr. person-I hope a good deal of her efforts are in this aspect.

 

p.s. The bonanza/Baron are considered one of the most delightful, fun, and well harmonized controls of any aircraft. Why are they called Dr. Killer's, and considered dangerous for new pilots?

 

Simply because they are so clean-get the nose down and they build up airspeed rapidly. Pull back on a winter day to 15" and go into a 500 fpm descent and you will be kissing yellow in the airspeed-maybe into it a little. Go to 700-800 and you can be in trouble fairly quickly. There are a couple techniques to avoid this one learns after a while when atc dumps you above your airport too high.

So-a simple answer-know your competition! If you want to know what a Bonanza (and the Baron is the same except a little heavier) controls like-get the Carenado Bonanza-see how it reacts with no stability adjustments/joystick adjustments. They got it right! The feel of momentum, and the wonderful control response of a Bonanza is all there to marvel at.

 

This is an interesting suggestion, but the "feel" of a sim seems to be a largely subjective thing, so what might feel "just right" to one person will feel all kinds of wrong to another.

 

Case in point, some people here think that "just right" means a plane that can fly straight and level without touching the yoke while "just right" to Tom means a plane that requires constant input adjustments (which matches his real world experience).

 

So there's two problems to be solved: 1) What is mathematically correct; and 2) What "feels" correct. The first is considerably easier to solve than the second.