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PhilTaylor

Acceleration: Autopilot on meth

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I've whined about this problem before, but I never got a satisfactory answer, so I feel it's worth whining about again.Here's the scoop:If I use altitude hold (in Acceleration) in a jet and increase the simulation rate to 16x, the aircraft bounces like a kangaroo, sometimes deviating down to 500 feet from the intended altitude before overcorrecting back up to 500 feet above my desired altitude. This also happens at 8x speed.This does not happen when I am flying below ~.60 mach or if I do not have altitude hold engaged.I'm really about to lose my mind. I turned the realism settings all the way down to see if that would help, but it didn't do anything.

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I think I remember Phil saying that, because this is so out of the range of normal sim use that it's a problem you're unlikely to get a solid answer to.

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Do you know how I could tinker with the autopilot in the fsx.cfg file?

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I doubt there is a solution to your issue.Autopilots work on the principle of a feedback control loop.Several times a second , the sensors determine if the airplane is straying off the set course / altitude etc and provide control inputs to bring the plane back on track as required.Because of ever changing wind conditions, the plane can be fine one moment and off the next. If you now try to fly 16x as fast, the errors also potentially multiply by 16 and the autopilot has to provide much larger control inputs to correct. This is similar to a pilot over correcting his airplane at the controls and the wild flying behavior you noticed results. At some speed, the autopilot will be unable to provide the controls required and the control loop gets unstable. In the real world, the autopilot will disconnect if it detects that the flying error exceeds what it can handle and that is actually what should happen at your 16x speed unless you have all weather, wind, etc turned to zeroand the airplane flies straight as an arrow with no disturbance.

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I don't think there is any solution for 16x sim rate and autopilot--that's by design.Try 4x sim rate and see if that doesn't help.RhettAMD 3700+ (@2585 mhz), eVGA 7800GT 256 (Guru3D 93.71), ASUS A8N-E, PC Power 510 SLI, 2gb Corsair XMS 3-3-3-8 (1T), WD 150 gig 10000rpm Raptor, WD 250gig 7200rpm SATA2, Seagate 120gb 5400 rpm external HD, CoolerMaster Praetorian

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I fly in 4x all the time when I'm doing long hauls in a 747. The only problem is, those flights are 5+ hours long, and spending over an hour sitting in my chair watching the clouds go by.I did not have this problem before I bought Acceleration. What changes brought by this expansion pack could be causing this?

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Dude, where the heck are you flying to/from?Boston to Heathrow is only 8 hours in real time.

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Currently I'm making my way from Aukland Intl in NZ to Darwin Intl in Australia. Mr. Navlog says it's going to be about a six hour flight.

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5:31 / 4x = a little over 1.5 hours of sit time (2 if you count landing/takeoff at 1x)Edit: But then again, why would you ever want to leave New Zealand?

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>>I did not have this problem before I bought Acceleration. >What changes brought by this expansion pack could be causing>this? I don't know.But I can say that I have encountered the same problem pre-Acceleration, and in fact in FS2004.I think it might also have something to do with flight dynamics, (the aircraft.cfg and .air files).I really think the best solution is 4x, at least that's how I avoid the problem. Really in my opinion, even for long-hauls, 4x is plenty fast enough. Plus your AI won't get reset at 4x. But at 8x and 16x they will get reset.RhettAMD 3700+ (@2585 mhz), eVGA 7800GT 256 (Guru3D 93.71), ASUS A8N-E, PC Power 510 SLI, 2gb Corsair XMS 3-3-3-8 (1T), WD 150 gig 10000rpm Raptor, WD 250gig 7200rpm SATA2, Seagate 120gb 5400 rpm external HD, CoolerMaster Praetorian

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True. I have Ultimate Traffic and resetting the AI is a real pain in areas with large airports.I'm going to take a look around some aircraft.cfgs and see if I can make a few tweaks. I've already done a few things with the Baron to make it flyable with my sub-par joystick.

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I too have this problem when using the autopilot and anything higher than 4x time acceleration. In fact, I posted in the forums about this problem, shortly after Acceleration was released, and no one replied to my topic. I just want to clarify that I DID NOT have this problem, prior to installing Acceleration/SP2. I even had a coworker try the same scenario on his system, and he too encountered the severe kangaroo like behaviour. I really don't think there's any way to fix it, other than uninstalling Acceleration (which I did, and the kangaroo like behavior disappeared..) Too bad, I was enjoying some of the additional features in Acceleration....Cheers

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Let's start an Anti-Kangaroo Autopilot Behavior group.I went into the 747 cfg and reduced the pitch and trim effectiveness by just a hair, and it helped a bit, but I don't want to tinker with it anymore because hand flying a 747 will obviously become a problem when my trim isn't responding as much as I need it to.

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I have had problems with "bouncing" aircraft at 4x AP and greater, with FSx, SP1 + SP2 (I don't have Acceleration). I think it's a weather effect, multiplied by AP speeds over 1x.I find that even at standard rate, you need to keep an eye on jets at high Mach numbers; a sudden change in wind can quickly overstress your bird, and that issue grows exponentially as AP multipliers increase.IIRC, the LDS767 forums deal with this specifically, to say that 16x AP is likely to cause issues - and I have certainly found that limiting AP speeds makes life easier.Alternatively - look carefully at trim. For my part, I've found AP is generally iffy unless you are sensibly trimmed for level flight before it's engaged. If you're trimmed with much nose up on ascent and just slap on the AP, the sim seems to me to react poorly. A decent trim for me makes AP behaviour altogether more predictable.Good luck.

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Another issue with 8x and 16x is if you use an add-on weather program. They will work, but not as effectively is what I'm told. I know Jim Skorna and the dev's have said that ASX/ASV6 don't render the weather as effectively at 8x and 16x.RhettAMD 3700+ (@2585 mhz), eVGA 7800GT 256 (Guru3D 93.71), ASUS A8N-E, PC Power 510 SLI, 2gb Corsair XMS 3-3-3-8 (1T), WD 150 gig 10000rpm Raptor, WD 250gig 7200rpm SATA2, Seagate 120gb 5400 rpm external HD, CoolerMaster Praetorian

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