Trimming in MFS...

[jcomm 5,882]

I find that trimming is still good-old force trim model, used for ages in MSFS, also in other platforms like XP until recently, War Thunder, etc..

I would have expected that at least this MODERN FDE could bring us a more detailed modeling of trimming.

Take aileron trim as an example. You add aileron trim to your aircraft ( provided it allows for it ) and, irrespective of being airborne, or standing still on the ground, with or without your engines working, with or without any winds set, you'll be able to see the associated control surfaces move, like if it was "force trim".

I didn't yet have the time to check if MFS also inherited from the previous MS FS versions the limitation of modelling elevator trim like "stabilator-like" airline style elevator trim ? Probably this hasn't changed either ?

[Ilari Kousa 116]

Trimming is very difficult to model, as you don't have a force to trim against.

[jcomm 5,882]

26 minutes ago, Ilari Kousa said:

Trimming is very difficult to model, as you don't have a force to trim against.

Very true, and there is an array of possible solutions to model it - just saying I prefer the approach that, for non-force-trim systems makes control surface displacement based on "q" ( dynamic pressure ).

 

[Ilari Kousa 116]

Which sim uses this?

[markk71 4]

It also doesn't help that the trim speed in mfs seems framerate dependent.

https://youtu.be/bvfEZJjIicc

Edited August 21, 2020 by markk71

[jcomm 5,882]

1 hour ago, Ilari Kousa said:

Which sim uses this?

Well,

DCS, IL2 Battle of Stalingrad, X-plane 11.50... I don't recall if Aerofly FS 2 does it too.

In any of these 3 sims, there's an option only for neutral point in terms of stick free vs stick fixed approaches to modelling the trimmed forces.

For aircraft that did have trim tabs, in any of these sims you can check that the control surface moves only when subject to duynamic pressure, either from propwash / jetwash, or a combination of this and / or airflow.