View Full Version : Elevator trim....need to scale it down.

October 21st, 2010, 21:06
I am working on a restoration of the freeware FSD T-38 Talon (available on Simviation.com). Lots and lots of tweaking, lots of new skins. VC being totally improved visually.

One problem I have with the plane is pitch trim. One click of up or down trim will send the plane climbing like mad or diving like crazy. It is nearly impossible to get this plane trimmed out for pitch.

I have reduced the elevator trim efficiency by .1 (1.0 to .9)...and this really didn't make a difference. Now I know that I could keep reducing the efficiency by .1 or .05 increments until I find a sweet spot. But, is there an entry in the air file/config file that will reduce the amount the elevator trim moves per click. Instead of 1 inch of travel per click, for example, could that be reduced to 1/2 inch of travel?


October 22nd, 2010, 04:38
What you are looking for is Record 1101, Offset 170 Decimal. This adjusts trim effect per notch. If you are trying to the same thing with Aileron and Rudder Trim, they are at Record 516.

- Ivan.

October 22nd, 2010, 09:27
I just opened the air file for the Talon using AirEd and there is not a single entry in it...well, 2 entried. One says FSD-T38 and the other says "description=". That's it.....nothing at all.


Milton Shupe
October 22nd, 2010, 15:58
Dropping effectiveness by .1 is a 10% reduction.

Drop it to = 0.2 and adjust from there. (an 80% reduction in effectiveness)

October 22nd, 2010, 18:57
Thanks for the tip Milton. Will give it a go.

About the empty air file with the plane....does that make a difference in the overall performance of the aircraft? I know that CFS2 pulls most of the flight characteristics from the air file, while FS2004 pulls the majority of it from the config file. Would having a blank air file cause an FS2004 plane to have poor flight dynamics?

Would using Air Wrench to generate a full air file be a good move? I have had some odd results with Air Wrench...not that there is anything wrong with the program...just that I have nearly NO idea what I am doing when it comes to flight dynamics. I have made some improvements to some planes, but that was mostly luck.


October 23rd, 2010, 10:54
If you want to give it a shot with AirWrench, this set of AIR and aircraft.cfg files I setup for Tim Conrad's F-5A with AirWrench might be a good start for you:


The unregistered version of FSUIPC has also been known to cause large changes in trim settings with one click with some flight models.

November 1st, 2010, 10:06
I am sure you do this, but always worth mentioning.... Set the trim in the controls section such that it will not run continuously, but requires a number of button pushes, and certainly do not put it on an axis. So far this has been satisgfactory for all fo the FS planes I have encountered.

Good luck! T