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Bell417

Aileron Trim - Drift Problem

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There's nothing worse than hand flying an aircraft out of trim. Unfortunately over the past several months I've had a problem in BOTH FS9 and FSX with uncommanded left aileron roll. Any aircraft - single or twin immediately enters a slight left roll that has to be countered with stick input. I've read a number of old posts on this issue but haven't found a real solution.1. I know all about torque & p-factor. I'm talking about in flight cruise aileron roll.2. Adding a fat copilot seems like a kludge and is unrealistic as well. And I know I can add rudder trim on those ac that have it. But I want to fix the problem not work around it.3. I don't have payware version of FSUIPC so not sure how to access its calibration settings.4. Of course, I've calibrated in FS (repeatedly) and all appears fine.5. This is really hurting my enjoyment of FS - can anyone help?Thanks!

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Put a FAT guy in the right seat.... :-hah or more fuel in the right tank, or the autopilot, or aileron trimL.Adamson

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EXACTLY Like the real world. :)You can however, check it isn't controller drift by simply using the keypad `5` key - NUM LOCK off, this centralises the controls.Allcott

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I've had the same problem (and posted about it) and I am equally miffed about it.A fat guy in the right seat in a 172 fixes the issue and proves the point too. If you set him to say 220lbs in a 80kt climb, you'll have stability (bear with me, my numbers are there or thereabouts) - but once you enter level flight at say 110kts you'll need to get him on a fast track diet down to say 210, or you'll get right drift.I've been following the ILS tutorials at http://www.navfltsm.addr.com/index.htm(astonishingly good, btw) and this drift issue has driven me nuts. I have consistently found that right seat weight sorts the issue, but needs to be adjusted as you speed up. A pain, given that I'm hand-flying all these tutorials. And of course if you slow down enough in descent, you'll get the issue returning and a maxed-out Big Mac is order of the day for your passenger.One solution is to fly e.g. the Real Air SF260, which is stable as a rock. Also tends to show it isn't a stick issue, and flying with jets demonstrates the same point.Might be realistic, for all I know, since I've never flown a Cessna, or indeed anything life size; but I wish we could trim it away. Of course, as another poster has pointed out, that would maybe defeat the object, since if it's simulating the real world, the issue is one we should be pleased to have to deal with! Still, for me, the temptation to hit Z after 25 mins of drift correction is considerable...

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Thanks for commiserating Paul! As it turns out, I have a Private License and at least 50+ hours in the 172. It's stable and steady as a rock - none of this drift bologna. I have a logitech joystick with overly beefy springs and I get a hand cramp fighting the drift!I'll try to split the difference and go with a 200lb co-pilot (doesn't seem so fat now that I'm at 190! :) ) and will check out those ILS tutorials.I'm mostly a Level D 767 fan and shoot lots of instrument approaches with the FMS -- no hand flying. But with FSX it's back to General Aviation craft - primarily the mooney -- which I might add has the same terrible unbalanced trim. Thanks for the suggesstions and link!Todd

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Todd, that's really interesting. I had been kinda convinced that FSX was simulating something real. Interesting that your experience is not so. Good luck with the copilot weighting - see if you get the change with speed/climb that I've spotted. I do think you'll find it better, on the whole. I am quite sure it's not a stick issue.As for the ILS tutorials - they have improved my hand flying 100%. I've been forced to learn not to chase a VOR, how to lead a change of course, and how small inputs make all the difference. I'm even thinking about re-taking the FSX private pilot test, which till now seemed to require altogether too much finesse. The tutorials have opened my eyes - not to mention that I managed my first DME arc landing yesterday, so my navigation skills are improving too.Cheers,Paul

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Last year, I flew a 172 back to it's FBO after a bird strike which took out nearly the complete front windscreen. A friend of mine who encountered the strike, said that the whole aircraft was seriously out of trim, and sank like a rock due to drag when power was reduced. But for me, the plexiglass was replaced. However, this particular older Cessna required right foot for the whole 220 miles, since it was a bit out of whack (there is the proper word, but can't seem to think of it at the moment), and there was two of us to even out the load. Heres the deal; these Cessnas have a hand adjustable trim tab on the rudder, thats supposeably set for cruise speeds with an even balance in the fuel tanks and load. Don't always expect it to be right on. Since I do use rudder pedals, if the trim is a bit off; I seldom think about it, as I just ride the pedal a little. Would prefer to use auto-pilot for long cross countries if available.At least always plan on left drift for the takeoff roll, and climb. Trim will also vary with airspeeds, since it's just an adjustle tab, that you bend by hand.L.Adamson

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I use a MS FF2 joystick with FS Force 2 and I too have encountered this problem. Since many others have reported the existence of the problem using a range of other hardware, it would appear to be a bug in FSX. I would like to hear from ACES on this issue, since any rectification would seem to be in their court.Perhaps there is a mod that can be made to the aircraft.cfg file that can fix the problem?Cheers,Noel.

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>I use a MS FF2 joystick with FS Force 2 and I too have>encountered this problem. Since many others have reported the>existence of the problem using a range of other hardware, it>would appear to be a bug in FSX. >>I would like to hear from ACES on this issue, since any>rectification would seem to be in their court.>>Perhaps there is a mod that can be made to the aircraft.cfg>file that can fix the problem?Well..............It's not a bug! I just took the FS9 & FSX Cessna 172 for a joy ride, as well as the FS9 Mooney. I'm using a Saitek X-52 joystick calibrated through the MSFS programs, and rudder pedals.All three of these simulated aircraft behaved just fine, when it concerns rigging for yaw & roll. When flying in level flight at cruise speeds, and with an even passenger/fuel load; it was no problem to merrily fly straight along, and then experience a slow drift situation to either direction.And that, is just as these real planes are. They don't always remain true on course with no small pilot corrections. If they did, then there would be no need for auto-pilots!And FWIW, since someone mentioned the Mooney; these models do have rudder trim, should it be required. But in the meantime, regardless of these reports by others, ACES has done just fine with the models in question.L.Adamson

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Glad you enjoyed your test flights. Unfortunately, what I, and I believe others are encountering is more than a very gradual banking of the aircraft off a desired course after flying around at cruise for 10 minutes... Instead the roll is prounounced - and will result in a 30 degree heading change within 30-45 seconds. That's no gradual drift. This occurs despite full joystick calibration/key centering and when the a/c should be in a neutral trim state. It is a bug - either in ACES code or in some interaction with some other module. FSUIPC is the only other thing I could imagine as it has got to be related to the joystick/control inputs (I get it on a Logitech as well as on a Xbox 360 controller). It's in both FS9 and FSX. I'm well aware of how to trim an a/c equipped with trim tabs and I can add all sorts of fat copilots, but as I stated initially, these are kludge work arounds. We are being forced to put the plane out of trim (per the simulator) in order to get straight and level flight. Not questioning the a/c modeling - just requesting help on uncommanded inputs affecting almost all default prop a.c - a problem that many would seem to know about.T

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Like Larry and Geoff, I don't have the problem -- now. However, I did experience it once. And it turned out to be a self-inflicted problem.Before flying the C172, I had been flying some aircraft with both aileron and rudder trim. I had inadvertantly changed the aileron trim and did not correct it before selecting the C172. The C172 "remembered" the settings from the previous plane and was exhibiting a serious out-of-trim condition.Here is how I proved it (try this yourself). Get your C172 airborne then enable the autopilot Heading Hold. Look at the turn coordinator. The ball should be centered. If the ball is not centered, then something is out of trim (and the autopilot is correcting for it).Now here's the interesting part, even though the C172 does not feature aileron trim I was able to correct the out-of-trim using the aileron trim key chords while still flying the C172. I believe the keys are Ctrl + Numpad4 (left) and Ctrl + Numpad6 (right). I watched the turn coodinator and tweaked aileron trim until the ball was centered. I turned off the autopilot and the A/C behaved normally.I should mention that this was FS9 not FSX. I am assuming that the same thing can happen in FSX but I have not tried it.R-

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>Got to report-no problem here either....>Would suspect your joystick controls...>Me too.Look at the rudder, and ailerons from the spot view, top down. See if it's centered.

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Does this happen constantly? Or intermittently?Reason I ask is I used to experience something like that in the Shockwave P-51. Would take 3/4 opposite stick to correct and after awhile it would go away. For some reason I started thinking turbulence and in the FSX.cfg found a line like "maxturbulence" (not sure of the spelling right now) and it was set at 1.0 so I changed it to 0.30 to reduce the effect and after that my P-51 did not have near as much problem.May not be the same as what you're seeing, but when you talked about a 30 degree change if 45 seconds, that sounds like what I was experiencing.Phill

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I get this problem too. If I have enough altitude I apply full left rudder (or the direction of the drift) and that usually fixes it. If that doesn't work, you can try banking steeply in the direction of the turn. I hope this helps. :-)

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