Hello,I recently had a pilot friend who is type-rated on the 737NG's fly my PMDG 737. Neither of us could find a way to accurately trim the aircraft for level flight; it appeared to have pitch instablity of some kind. We noticed that even with autothrottles engaged and holding constant IAS, the aircraft could not be trimmed out to level flight.I'm using a Saitek X-45 joystick and have it programmed with pitch trim on one of the hat buttons via FSUIPC, carefully calibrated by the same. I have pitch trim set to one increment per button press.How are you guys managing to trim out your 737's?Thanks very much.

"How are you guys managing to trim out your 737's?"We usually let the Autopilot take care of it :-hahDo you have any add-on weather programs running?Perhaps it's to do with your joystick null zones? Electical noise may be causing your joystick to produce nose up/down signals even when your joystick is centered.Hope this helps.Cheers.Ian.

> I have pitch trim set to one>increment per button press.>>How are you guys managing to trim out your 737's?>>Thanks very much.Try the following:Edit the aircraft.cfg, go in flight tuning section and you will seeElevator_trim_effectiveness=1Change 1 to a value of 0.5.It should look like this:Elevator_trim_effectiveness=0.5Save the aircraft.cfg and give it a try. With this value the electrical trim sensitivity on your joystick should work.Your problem is related to the joystick not to the airplane. I had a similar problem like yours.It is very difficult to find a precise tuning for each joystick

Hi Ian and Alex,Ian - I've tried just about everything regarding weather, weight and balance, joystick null zone, calibrating to the nth power, ect, just not having too much luck :) Thank you for your advice and taking the time to respond to my question!Alex - I will give your suggestion a shot! Thank you! I think you are on the right track about my joystick problem, it's just too over-sensitive on stab trim no matter what technique one uses. I can't wait to try your suggestion, thanks again!

Hi Dianne,Just let us know how it works.

Dianne,You might also consider assigning one of the rotaries on the Saitek throttle to trim.I have the one on the front of the throttle assigned and calibrated through a registered copy of FSUIPC. Although I don't use for the 737 I do use it for GA aircraft when I fly those.Dave

Hi Dave,I will try that, good idea. Thank you.

Hi Alex,I'm taking your advice and am trying to find a elevator trim value that meshes well with the Saitek. I will let you know what seems to work the best. Reducing the sensitivity in the .cfg file definitely does help a lot, thank you so much for the information!

Hey all.Dianne,Be careful if you do decide to use one of the rotaries for trim. If you go this route, you will have to take extra care engaging/disengaging the A/P, and be careful not to touch trim while the A/P is engaged. Obviously, the X45 hardware cannot follow the A/P commands, and you will usually have a mismatch between the sim and your hardware, say, when going manual on short final. It does work, but, just keep that in mind.I've had my X45 for awhile now, and I've settled on the 4-way hat, on the throttle, that sits under the index finger. I've tried many, many different configs, and this feels the most natural to me. YMMV.

Any time!Happy to see that is working.

I agree with your caution on using any joystick button/rotary for trim Brian because it can give the a/p problems.Although I don't use it to trim the 737NG I do rotate it back and forth and then to centre before take off to make sure it is not sending any inputs and then use VNAV.Once or twice I have forgotten to centre it but you soon find out when the a/p keeps disengaging :-)