This is not an MD11 problem - I have it on other payware, but this is the plane I´m flying at the moment so here I am.........Lets take it as read that all weights and CGs are correct and that the FMC-recommended Stab Trim is in the box in the SD window. I take off and set Autoflight, and immediately hear "Satbilser Motion" warning and see that the horizontal stabiliser is far from horizontal and is moving - flicking up and down slightly - on its axis, and the plane is porpoising like crazy. If I touch the trim wheel or my assigned yoke buttons the AP disconects and the plane goes verical. If I wait out the climb and reach my set Alt the stabiliser is still not straight (flat), is still moving on its axis and the plane is still porpoising.I use a CH yoke calibrated exclusively thru FSUIPC, there are no PMDG menu settings and no FS assignments.Anyone have any ideas about this?

Do you have an axis assigned for elevator trim? If yes, try disabling it and see if the problem happens again?

No axis assigned, but it was a smart thought.A bit of info to help me understand things:Real World:Does the whole horizontal stabilizer actually move - rotate on an axis - on a real plane? Is that what trims the aircraft?Once at the assigned level flight, what causes the h-stabilizer to "centre" to neutral?PMDG:Why do I get that "Stabilzer Motion" warning?Is it normal for any touch on the trim wheel or trim buttons to de-activate the AP and for the aircraft to go - literally - vertical? If I have set the trim to that given in the SD why does the plane go vertical¿Is there anywhere else I could look to find the casue of this?

Hi, the problem is the axis assignment through FSUIPC. The MD-11 needs the controls passed through the FS-Interface to work properly. Jan-Paul

northridge,Sign your posts with your full name, otherwise the moderators may remove them. To answer some of your questions:Yes, the whole horizontal stabilizer moves. In big jets, like MD-11, the elevator trim always moves the whole horizontal stabilizer in order to get the required trim force.My understanding is, that the autopilot disconnects when the the controls are moved by the pilot, including the stabilizer.The "stabilizer motion" warning is activated when the stabilizer moves CONTINUOUSLY a certain amount.From the problem you're having, all I can think of right now, is that something is actually interfering within your controls. Have you checked that you don't have any other buttons/axis on any other controllers assigned to the elevator trim?

Still struggling with this.As soon as I Autoflight the stab trim goes from my input (say 5.7) to something stupid like 15 and the plane goes vertical.I have NO axes, keys or buttons - whether they be FSUIPC, CH, FS9 or PMDG - assigned to elevator trim.Of my installed heavies only the iFly 737 doesnt show this problem.Nicholas Ferguson

Is it normal for any touch on the trim wheel or trim buttons to de-activate the AP and for the aircraft to go - literally - vertical? If I have set the trim to that given in the SD why does the plane go vertical?

I have NO axes, keys or buttons - whether they be FSUIPC, CH, FS9 or PMDG - assigned to elevator trim.

Confused here. I'm assuming you're talking about the buttons in the VC/panel, but the only thing I can assume is external, since it is more than one aircraft reacting this way. Try to fly with the mouse or keyboard (no stick), to see if it is something caused by hardware. And yes - upon pilot intervention (through trim, or a force on the control wheel, or otherwise) the AP will disengage, though it will not send you vertical.

Still struggling with this.As soon as I Autoflight the stab trim goes from my input (say 5.7) to something stupid like 15 and the plane goes vertical.I have NO axes, keys or buttons - whether they be FSUIPC, CH, FS9 or PMDG - assigned to elevator trim.Of my installed heavies only the iFly 737 doesnt show this problem.Nicholas Ferguson

If only the iFly does NOT show teh problem, that points very strongly to a controller issue. Could it be something lik the trim-up button is sticking on? Have you tried testing and calibrating your joystick independently of FSUIPC?

Have to repeat: there are NO assigments for trim in FS, CH, FSUIPC or PMDG.Just installed and flown the CS 757 with no trim problem.Regards the trim value shown in the SD panel: I input the FMS-calculated 5.7 (for example), the plane takes off at a controlled angle, but once I go Auto the value shown on the SD is 15.I get exactly the same problem with the LVLD 767.

It looks like you have a trim runaway problem...Try checking the control acceleration fix in FSUIPC...Andrew

But surely setting the Spike fix in FSUIPC pre-supposes that I have trim configured to a button/key/axis within FSUIPC? Which I dont.ThanksNicholas

Can you tell me what are your T/O and ZFW CG values? Have you tried disconnecting (plugging off) all your controllers and see if the problem still occurs?

Have to repeat: there are NO assigments for trim in FS, CH, FSUIPC or PMDG.Just installed and flown the CS 757 with no trim problem.Regards the trim value shown in the SD panel: I input the FMS-calculated 5.7 (for example), the plane takes off at a controlled angle, but once I go Auto the value shown on the SD is 15.I get exactly the same problem with the LVLD 767.

And I have to repeat - if only the iFly does NOT show the problem, that points very strongly to a controller issue. When you say "NO assignments" I don't think you think you mean what you think we think you mean. How do you input the FMS calculated trim if you have no assignments? FSX has default assignments for keyboard and joystick buttons. Do you know which buttons have been assigned to trim and have you confirmed that they are not sticking.

"No assignments" means that I have disabled all button/key/lever input from the MD11 elevator trim: there is nothing that allows me to input the FMS trim value.Why? To see if removing the input removed the problem. Result - it doesnt: the elevator - the whole wing, flicks up and down just the same as when I had a CH button assigned by FSUIPC to control elevator trim. And I get Stabilzer Motion warnings all the time.How can I fly without any elevator trim control? Well obviously I cant, but seeing as I cant fly with it .............As well as the previously mentioned 737 I have confirmed that this problem doesnt occur with a payware 767.

"No assignments" means that I have disabled all button/key/lever input from the MD11 elevator trim: there is nothing that allows me to input the FMS trim value.Why? To see if removing the input removed the problem. Result - it doesnt: the elevator - the whole wing, flicks up and down just the same as when I had a CH button assigned by FSUIPC to control elevator trim. And I get Stabilzer Motion warnings all the time.How can I fly without any elevator trim control? Well obviously I cant, but seeing as I cant fly with it .............As well as the previously mentioned 737 I have confirmed that this problem doesnt occur with a payware 767.

Sorry, but I am not telepathic. It is hard to know what you have or have not done when you say you input the trim value and then say you have disabled all means of inputing the trim value. With that in mind, assuming you would like to solve this, do you mind if we go back to basics. What are the results when you unplug your controller?