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Guest Totalbeginner

74X Autopilot Pitch Instability

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Can somebody help me out with this one because it's driving me crazy.For some reason, I can't get the autopilot to function as well as it does on the FS9 version in pitch.With the A/P engaged, the aircraft bobs up and down like an ocean liner! It's less pronouned in ATL HLD or VNAV ALT, but is very annoying in the other vertical modes, such as: VNAV PTH, G/S.What could the problem be?

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This forum requests that you sign your real name... The 744X pitch control is same as fs9 744 on my machine, and I don't have much power so the best I get is about 12-19 fps. Low frame rates will cause instability, as well as weather induced problems. FSX weather is actually worse than FS9 but the latest registered version of FSUIPC does a good job.So, let us know you name and a few more specifics about your pitch problem. Climbout, cruise, approach? How much pitch deviation? Got a screen shot?

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I'm getting 18 FPS so I don't think it's that. It's most obvious during a VNAV decent. As soon as VNAV PTH is annunciated, the rollercoaster starts! I have all of the FSX weather options switched off, just the basic "clear skies" loaded. :-(Martin Neep

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Martin,I'm the wrong guy to answer this, maybe others will chim in. I really don't like the VNAV descents either, seems like she will nose over and accelerate downward past 4000 fpm then raise the nose and overcontrol and chase the descent profile for a cycle or two... so, I always use SPD/V-S mode and let the VNAV vertical path indication on the ND guide me. However, once she settles down in the descent, my simulation will glide down nicely... only "oscillations" are while getting the descent established. Is this what you are experiencing?How is your pitch stability in the other flight segments?

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The wobble always occurs as long as I have any weather turned on other than "clear skies". However, after a recent disk failure resulting in a complete reinstall, I found that clicking on Addons>FSUIPC>Clear all weather *seems* to have fixed the problem. I have the non-registered version of FSUIPC.danp.s. the up-and-down has been so bad at times that it's made me motion sick.

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After searching the forum for this "wobble" "pitch" issue. I came accross this post.I am using PMDG 747X FSX sp2 registered FSUIPCI am getting a slight nose-up nose-down during cruise. Using VNAV.It's like it's chasing something. The V/S indicator is always going slightly up and down.This is with NO weather. It's not a violent movement but enough to make thenose go up and down all during cruise.During VNAV descent a similar type up and down occurs.About 15 miles out ( at level flight) from GS intercept it starts chasing speed. Speedfluctuates 3-5 knots and engines spool up and down trying to hold the set speedWhen in final the nose up nose down thing starts again until just about 2 miles outand then it settles down a bit.When I use weather (ASX) the behaviour is about the same.I have tried a full uninstall and reinstallI saw a few posts like this about similar issues and none of them seem to haveany solutions.I'm at wits end trying to smooth this out, but I just don't know what to try now.I've tried just living with it, but it's make you dizzy after a while :-)Some guidence would be really appreciated!RegardsDave Graham

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