Pitch Trim & Aileron Sensitivity when disengaging AP

[Mike A 337]

Hi,I've seen the earlier posts regarding pitch trim sensitivity. When I hand fly the Tinmouse II, I have no problems with pitch trim. But when I engage the autopilot to fly it in CWS mode, after disengaging the AP and going back to hand flying, I find that the pitch trim, as well as aileron control, are a lot more sensitive, to the point of being excessive, as compared to hand flying before engaging the autopilot. Anyone else have this situation? Any clues to what might be going wrong? I have the electrical & hydraulic systems set properly in the overhead panel.Mike A.

[Macsm 0]

I don't know about sensitivity, but I find that when I disengauge the AP, I see a strong "pull up" tendency. I doubt this is correct as the AP is supposed to trim to stable. Not sure about the sensitivy though issue though.regards,Macs :)

[CF104 0]

Hi Mike,I get the same thing. Fine before using the AP and very sensitive after disconnecting the AP.Cheers,JohnBoeing 727/737 & Lockheed C-130/L-100 Mechanichttp://www.sstsim.com/images/team/JR.jpg

[Bob Scott 7,716]

Are you seeing increased sensitivity at the same indicated A/S and mach number? If you engage the CWS in a climb, then disengage at altitude where the mach number is much higher, yes, you will see considerably more pitch sensitivity. I can't reproduce a change when the CWS is engaged and disengaged at the same speeds.RegardsBob ScottATP IMEL Gulfstream II-III-IV-V L-300Santiago de Chile

[Macsm 0]

Bob, I am not sure about increased sensitivity, but whenever I turn the AP off on final, the airplane pitches up violently. I make a point not to touch the joystick when I disengage the AP, so it is not user induced. Any ideas? Thanks,regards,Macs :)

[Mike A 337]

Hi Bob,Just to confirm it, I did an approach, speeds below 200 kts. Before engaging AP, applying pitch trim seemed normal. Engaged the AP for a minute, then disengaged it, applied pitch trim, and it was greatly exaggerated. Aileron control seemed OK.Mike A.

[Bob Scott 7,716]

Please send me the weight, CG, and configuration you're using. I can't reproduce it. I get a mild and barely noticeable pitch up when disconnecting the AP at the end of a precision approach. It sounds like this might be a loading/weight and balance issue.RegardsBob ScottATP IMEL Gulfstream II-III-IV-V L-300Santiago de Chile

[CF104 0]

Hi Bob,It's not an IAS sensitivty issue. The issue being that the trim speed more than doubles after disconnecting the AP as opposed to the trim speed prior to the first AP engagement.Cheers,JohnBoeing 727/737 & Lockheed C-130/L-100 Mechanichttp://www.sstsim.com/images/team/JR.jpg

[Bob Scott 7,716]

I still can't reproduce it or find anything in the code that would affect the trim speed. I normally program my joystick buttons (including trim) using the Buttons + Switches tab in FSUIPC, but I've tried direct with only the FS interface and still see no change in the rate of trim application before and after use of the A/P.Another possibility is the dreaded control acceleration problem in FS, which FSUIPC (the payware version) easily fixes if you select the "fix control acceleration" checkbox in the FSUIPC Misc tab. The control acceleraton problem could result from the rapidly arriving internal FS controls sent by the panel gauges...if that's it, the only fix I know of, short of dumbing down the panel significantly, is in the payware version of FSUIPC.CheersBob ScottATP IMEL Gulfstream II-III-IV-V L-300Santiago de Chile

[Mike A 337]

Hi Bob,Thanks so much for your reply. I wasn't aware of the control acceleration glitch. I checked that box in FSUIPC, and now it works fine. Now I can do some longer flights using the AP instead of hand flying all the time :-yellow1 . Thanks again!Mike A.

[Macsm 0]

Bob,FS is the culprit and FSUIPC takes care of it. I had forgotten about this issue, as it had happened on other aircraft as I remember. Just check on the "fix control acceleration box" and whala! This did the trick fer me! :) Thanks agian Bob! :)regards,Macs :)P.S.: Please DON'T "dumb down" the panel. Please!!! :)

[Bob Scott 7,716]

Thanks gents...saved me from embarking on a fruitless goose chase.Regarding any "dumbing down" of the panel...no worries, in fact the next version will be going in quite the opposite direction.CheersBob ScottATP IMEL Gulfstream II-III-IV-V L-300Santiago de Chile

[pedwards 20]

I also had the same problem with the trim after autopilot disconect, but has now been fixed using FSUIPC. On hearing about the next version, all I can say is WOW. I have aircraft corroding in my virtual hanger that cost

[Bob Scott 7,716]

Thanks for the kind words. No donations. Freeware is...free!That said, there are always ways folks can contribute to the project i.e. documentation, high-quality digital panel photos, repaints, effects, load managers, fuel planners, good ideas etc.CheersBob ScottATP IMEL Gulfstream II-III-IV-V L-300Santiago de Chile