Geofa...definitely clarifies a lot. A few points:

 

 

I propose something here that is very difficult to prove....and that is the lack of peripheral vision in a desktop sim. What we generally deal with is akin to putting on blinders....and the lack of peripheral input, IMO, makes our perception and anticipation of response much more difficult. The rods in our eyes are the super-sentive ones of course and in reality, we have a "heads up" to take corrective action that we dont' get in a sim until it' too late...therefore we have to focus even harder with a desktop sim. We don't have "early warning rods" and with brain processing in billionths of a second (for most anyhow ) that's enough time lost to make us feel like we're always behind. Anyone flying IFR "in the soup" knows how mentally draining it is without that extra visual input, its exhausting. I think anything short of a full surround screen will keep this problem at the forefront....so then, how to deal with it is the question?

 

 

 

As far as the Carenado aircraft...I do not know what they do, but I would not yet go so far as to assume they have it right "across the board"....this is because I've seen some developers use some techniques that I myself do not use because it causes unrealistic behavior in other flight regimes....and depending on the importance of the regime, I might not go there. I can think of a 100 ways to 'fool' a user and attain any one performance parameter to convince anybody of anything using any method as long as they don't dig around under the hood and complain about what I put there. Now if countering the aforementioned problem due to lack of peripheral vision means "going there" in some cases and stretching the model to make it behave well in a flight regime deemed most important....then I can't argue that...perhaps that what Carenado has pursued.

 

In the engineering world....in finite elements at least, we may do several models depending on what we're after and the level of detail. A model sufficient for one regime isn't sufficient for another and I WILL contend that to me, I find it perfectly acceptable to have multiple flight models of aircraft optimized for certain "simulation scenarios". Thinking a single model can work across all scenarios is not a valid assumption in the world of numerical simulation, which is what XP is....and I think we all (myself included) can fall victim trying to make a single representation universal...like some challenging puzzle with no solution but because we never reach it, we believe we just haven't solved it yet and fight a never ending battle. Unless a model is tested across all regimes, it can't be said that is is accurate across all. My engineering experience says this doesn't really exist, something is always sacrificed, approximated or "ignored" as not relevant for the solution sought.

 

Now as to why the real baron doesn't roll with no trim as you say...that is intriguing to me....I'd ask "at what speed" though? I see a tab on the right trailing edge of the main wing....what is that for? An aileron trim tab? If XP doesn't model the effect of propwash countering the torque enough...then chasing reality is impossible except with alterations from reality. I could use a trim tab, but that would be "speed dependent". A baron might not roll in cruise as the trim tab is set to counter it...but at lesser speeds it would, etc. It's mathematically impossible (balance of forces) for a Baron to exhibit no roll from standstill to cruise with a non-altering surface / power configuration....so the question is, "what is the configuration at any given speed". (us engineer types would translate that into a force diagram where forces must balance if the plane is non-rolling/pitching/yawing) If you contend that the Baron never needs roll input (yoke, trim or trim tab) ever in any combination of power...be it takeoff, steep climb, etc....then I'd have to contend that just doesn't jibe with my aircraft design education and there's something missing from the equation we have yet to account for....it might be as simple as XP's ineffective propwash model and if so, we'd simply have to depart from reality a little bit to adjust. For many, the simple application of some aileron trim suffices....but I consider this a deeper "mental journey" into the XP flight model toolbox for our daily dose of cerebral exercise.

 

Currently, I have no setting to counter torque on the Baron currently...it will roll from straight and level until I put something in to counter it, or you do (like trim). I could set both engines to counter-rotate...but animate the props in the same direction to fool you, but that is an example of an area I won't go...I'd rather understand it all and make it work. I agree with jcomm that I think the real effect from propwash is stronger than that in XP....and possibly in combination with an aileron trim tab is what balances forces in cruise...that is my hypothesis as of today. With no trim tab on the XP Baron...and a 'weak' prop-wash model, I would expect it to roll. I can "up" the aileron tab to make up for XP's weak propwash effect on the wings (for a twin)....but it would then overcompensate and roll the plane in certain instances (like when power is removed at cruise) and the aileron tab overpowers the yoke.

 

I would say that probably the one thing I do that most do not that makes me go one way or the other is I test across a broader regime as the developer...and if I get good behavior in one area, but not in another, I might decide to make concessions so no one area is perfect. I test with slow speed or engine out or engine out with flaps, hard turns, full deflection with each engine out, both out, at high altitude, low altitude, low fuel levels, high fuel levels, etc and try to find middle ground. I can probably be convinced though to say, " those regimes are fringe enough to be sacrificed Tom...get with it and focus on normal operating range", the assumption being that for a sub-100.00 flight simulator...you won't get perfection in all flight attitudes.

 

Tom K

 

P.S. I am SUPER guilty of rewording my posts AFTER posting...be wary as I may clarify or include new info to better make my point...especially on my longer-winded posts...usually I get to a "final form" within 5-10 minutes of posting....best to wait till my post time + 10mins to be sure it's in a final form....sorry

 

I'll try to keep it simple in my reply. A Baron with some differences is basically a Bonanza with two engines.

My Bonanza had no rudder trim, an aileron trim which was never needed and pitch trim only.

 

 

Differently-my Baron had all three trim controls. Only time I ever used rudder trim was in engine outs. Otherwise I never ever had to touch rudder/aileron trim (When this thread started I actually had to tax my brain to remember where the rudder/aileron trim were). A Baron is very stable and does not roll by itself in a matter of seconds to a 45 degree bank once trimmed for level flight. It does not need either rudder or aileron trim-unless of course it is misrigged which would be a one time adjustment.

 

Again-the stability/trim tests are pretty standard and have nothing to do with a users "feel" or a different joystick. From an engineering standpoint I would think that would hope it would be relatively "easy" to take care of. All spelled out in Part 23 of Far's for aircraft certification.

I think anything short of a full surround screen will keep this problem at the forefront....so then, how to deal with it is the question?

 

Well, the first step is convincing the wife that I need a 360 degree display system and a computer powerful enough to drive it... after that, the rest is easy.

A Baron is very stable and does not roll by itself in a matter of seconds to a 45 degree bank once trimmed for level flight. It does not need either rudder or aileron trim-unless of course it is misrigged which would be a one time adjustment.

 

This is / was the reason for my initial post. It has morphed into something much more and that's great, but it was the unstoppable rolling side to side that I was questioning. No amount of trim would work. You could get it somewhat trimmed for level flight and it rolls over (in seconds) on its own, give opposite trim to counter that roll and it goes over the other way, with only one "click" of trim. There's no way it should be that sensitive to trim inputs.

 

Glen

 

Just to go back to my larger rc aircraft. I can trim them out for level flight and they stay put for the most part. If I need to give a click or two of opposite aileron trim it will settle itself out, not start immediately rolling in the opposite direction. These aircraft (the real ones) being much bigger and heavier should in my mind react much less to trim inputs as compared to my rc aircraft, but they don't. Their way more sensitive. Now, we do use expo "exponential" in our radios to "dull" the stick movement down, but still, their nowhere near as sensitive as the Baron. (was, it's getting better)

A good question to would be is this a problem with the fm-or a problem with modelling of winds, currents, and turbulence.

A good question to would be is this a problem with the fm-or a problem with modelling of winds, currents, and turbulence.

 

Good point! Yet, it is funny to see us in the other sim seeking exactly for add-ons that make our ride bumpy, either in the form of weather injectors or dynamic cameras :-)

A good question to would be is this a problem with the fm-or a problem with modelling of winds, currents, and turbulence.

 

Well, before I initially posted, I did my tests with absolutely no weather. Now I don't know if it's possible to totally get rid of all weather influences in XPX, but I went into weather and removed everything I could. Therefore the only thing affecting the aircraft was the flight model? and my yoke / rudder pedals / trim switches.

 

Glen

Ever take your car to a mechanic, and he messes something up, and when you go back to get it fixed he tells you, "It's supposed to do that"? That's what this feels like.

 

The fix might be as easy as reducing the rudder trim effectiveness. But we shouldn't need rudder trim at all unless the aircraft is asymmetrically loaded. An aircraft at normal cruise power and a balanced load had better damn sure fly hands off with neutral rudder trim.

 

Hook

Somebody said there's an option inside X-Plane that generates random Updraft and Downdraft, and it comes enabled as default, so you have to go there and disable it. Have you guys done it? Maybe that can make the FM more stable.

read the whole thing, and I think you make some great points. Pilots can instinctively keep a plane level because, among other sensations, they can feel the yoke wanting to deflect one way or another. They're flying level, the yoke starts tugging to the right, so they instinctively compensate by turning to the left. Having never flown a real plane before, I can only guess, but I wonder just how many of these minor, instinctive corrections happen subconsciously? Then when they fly a desktop sim, they no longer have their subconscious instincts working for them, and suddenly the plane is "unrealistically" rolling left and right.

 

I'll start here. BTW -- my earlier short response was because it was an I-phone. I can't stand writing a lot on those phones, and I had to leave.

 

Okay, so we're flying level. My balanced ailerons on floating on air currents, and manage to stay aligned with the rest of the wing, on both sides, because my airplane is rigged properly. Unless I'm hit by some kind of turbulence, the stick just does not want to start tugging to the right or left. It just wants to remain centered, since airflow is keeping both ailerons in a balanced position. If I push the stick right or left, then I can certainly feel that I'm pushing against the airflow over the ailerons.

 

Tkyler

 

I think that it is Larry. What we are dealing with here is equally cognitive and physiological as it is the flight model. I have flown a lot of long flights without autpilot in real life and it is mentally tiring...because you are always making sure you're on course and altitude. Flying is busy business. You say you have no wish to continully monitor the horizon...yet my flight instructor tells me to continually monitor the horizon (or the instruments). I think Mountain Man is also exactly right.

 

No, I certainly have no wish to continually adjust against a "computerized horizon". It get's very tiring, and the sim is off within five minutes. I'm way past this "busy business" for real life flights of perhaps 400 miles or more each way. I know all about the "horizon" for real flying..................and yes, I'll certainly use the two axis auto-pilot. I installed them, and I adjusted them. RV's can get a bit tiring on long flights, and many pilots use these A/Ps. Besides, our A/P's are high tech, solid state, work all the time, and are very accurate. I didn't want this to go down the path of Mountain Man being exactly right.............and that's the reason for my quick lunch time response. It's just not the right assumption.

 

Tkyler

 

Now as to why the real baron doesn't roll with no trim as you say...that is intriguing to me....I'd ask "at what speed" though? I see a tab on the right trailing edge of the main wing....what is that for? An aileron trim tab? If XP doesn't model the effect of propwash countering the torque enough...then chasing reality is impossible except with alterations from reality. I could use a trim tab, but that would be "speed dependent". A baron might not roll in cruise as the trim tab is set to counter it...but at lesser speeds it would, etc.

 

I've spent a lot of time getting airplanes wings rigged. Unless the wing incidence or building technique is way off, both wings should want to fly level with the ailerons in trail. If something is to far out of rig, then tabs may be required. My RV has a stick adjustable elec. trim tab on the right wing. I actively use it, just for passenger or fuel load. Without the tab, stick forces are light to keep level, but I prefer it. However, there is no noticeable "roll" movements in flight that have anything to do with this tab. This tab is not used as a variable for different cruise speeds. The effect of yaw, and much heavier forces on the rudder are much more noticeable with speed changes, than anything to due with roll. If a sim plane is displaying roll instability throughout it's cruise phases & speed changes, then it's just wrong, and certainly tiring.

 

I hadn't pinned down exactly what it was, between my real flights and turning on the sims afterwards. I could easily settle into FSX, and the plane felt fairly comfortable & much like the real one. Just as Geoff has mentioned, FSX "pitch" trimming still requires more work than the real thing. However............most X-Plane flights would last five minutes at best. Until Geoff brought up the term "hunting"...........I hadn't thought of the right term to describe it. I just found it annoying, and turned off the sim. I just didn't like duplicating any cross country with XP. And that's the problem! The sim is constantly hunting in roll as well as pitch, and requires to much to remain on course and altitude...............to the exclusion of almost anything else.

 

This has nothing to do with peripheral vision. I usually adjust the cockpit to get more vision from the sides, as it is. We just have to get rid of this constant requirement to adjust against roll in cruise flight. I've flown in numerous airplanes, including my own, where t

 

 

he roll/torque effect was noticeable and sometimes required aileron input on takeoff. But it just disappears as speed builds on climeout. I have quite a few photos showing my aileron positions on the climb, and they are in perfect trail with the wing.

 

L.Adamson

 

edit: pic. This is initial climb out of Page, Arizona over Lake Powell next to Glen Canyon Dam. Notice the left aileron, and how it's aligned with the wing. It's making no attempt to control any roll forces.

Unless I'm hit by some kind of turbulence, the stick just does not want to start tugging to the right or left.

 

You'll notice that I said that pressure on the yoke/stick is only one of many sensory inputs that might help a pilot keep his plane level. Whether or not it is the most prominent one is beside the point. It was just the first thing that popped into my head. Perhaps the horizon subtly rotating in your peripheral vision would have been a better example.

You'll notice that I said that pressure on the yoke/stick is only one of many sensory inputs that might help a pilot keep his plane level. Whether or not it is the most prominent one is beside the point. It was just the first thing that popped into my head. Perhaps the horizon subtly rotating in your peripheral vision would have been a better example.

 

Which is what is does now, when it shouldn't.

 

It's true...........as what we see on the screen translates to a sense of feel. When I get a sense of the aircraft rolling off one side or the other, my finger is hitting the trim switch to compensate. But when I do that, I loose a sense of airloads on the flight surfaces, which should be keeping the stick & plane level to start with. When I'm continually compensating, it gets to the point of being annoying. It's amazing what a bit of joystick spring pressure & visuals can do, if the model is programmed for it. I've never felt much of a need for force feedback, especially if it feels to fake.

 

Except for heavy turbulence & G-loads, my mind does fill in a lot of gaps, just due to the fact, that I'm use to what it should feel like.

 

Perhaps you've heard my examples of visual & sense of feel. You're sitting at a stop light, when a car on your side pulls slightly ahead. All of the sudden, you slam on the brakes, thinking you're rolling backwards. Same can happen in a car wash, if the overhead machine starts to move. It all depends what your visually concentrating on, at the moment.

 

L.Adamson

When I get a sense of the aircraft rolling off one side or the other, my finger is hitting the trim switch to compensate. But when I do that, I loose a sense of airloads on the flight surfaces, which should be keeping the stick & plane level to start with. When I'm continually compensating, it gets to the point of being annoying. It's amazing what a bit of joystick spring pressure & visuals can do, if the model is programmed for it.

 

Now I'm getting confused. When the aircraft starts to roll right or left (horizon cue) in normal power level flight should I not be using trim to compensate and "try" to bring it back to level flight? This is where I'm having the issue. It comes back, and goes the other direction far too easy. Or, should I be putting pressure on the yoke / stick to bring her level. Maybe it's what I'm doing that's causing my issues.

 

Glen

When the aircraft starts to roll right or left (horizon cue) in normal power level flight should I not be using trim to compensate and "try" to bring it back to level flight?

 

It depends... If it's due to turbulence/shear than you should in the very 1st place allways use your yoke/stick/rudder to respond. OTOH if you're leveling for cruise, or entering any other phase of your flight, you should set trim accordingly to relief stick forces, counter prop engine effects, fuel imbalance, etc..., trim for speed, etc...

 

On a sudden bank due to weather effects, it's the main controls you should be using, otherwise you will have to "undo" your settings sooner or later ...

 

Use trim for "the long run", control inputs otherwise ;-) - the concept of "long run" may vary according to the phase of flight you're entering... For example, during takeoff / initial climb on a powerful prop aircraft with rudder trim you will set your trim for takeoff to avoid a discomforting need for prolonged rudder input...

Now I'm getting confused. When the aircraft starts to roll right or left (horizon cue) in normal power level flight should I not be using trim to compensate and "try" to bring it back to level flight? This is where I'm having the issue. It comes back, and goes the other direction far too easy. Or, should I be putting pressure on the yoke / stick to bring her level. Maybe it's what I'm doing that's causing my issues.

 

Glen

 

I'll be more clear. I've already brought it back to level flight with the stick, just as I'd do in the sim. Within the sim, I'm slightly reducing pressure on the stick to see it it remains level. If it doesn't I'm trimming more.

 

In fact, I might have already been moving the stick to keep it level in the first place. But when I do, I sense pressure from the joystick spring, and then hit the trim button. That's the problem, as I shouldn't be continually doing so. It is "hunting" as described, and doesn't want to settle into a trimmed state.

I'll be more clear. I've already brought it back to level flight with the stick, just as I'd do in the sim. Within the sim, I'm slightly reducing pressure on the stick to see it it remains level. If it doesn't I'm trimming more.

 

In fact, I might have already been moving the stick to keep it level in the first place. But when I do, I sense pressure from the joystick spring, and then hit the trim button. That's the problem, as I shouldn't be continually doing so. It is "hunting" as described, and doesn't want to settle into a trimmed state.

 

Ok, thanks, no different than the issue I have, won't stay trimmed "without" any outside influences (weather).