• Which the release of FS2020 we see an explosition of activity on the forun and of course we are very happy to see this. But having all questions about FS2020 in one forum becomes a bit messy. So therefore we would like to ask you all to use the following guidelines when posting your questions:

    • Tag FS2020 specific questions with the MSFS2020 tag.
    • Questions about making 3D assets can be posted in the 3D asset design forum. Either post them in the subforum of the modelling tool you use or in the general forum if they are general.
    • Questions about aircraft design can be posted in the Aircraft design forum
    • Questions about airport design can be posted in the FS2020 airport design forum. Once airport development tools have been updated for FS2020 you can post tool speciifc questions in the subforums of those tools as well of course.
    • Questions about terrain design can be posted in the FS2020 terrain design forum.
    • Questions about SimConnect can be posted in the SimConnect forum.

    Any other question that is not specific to an aspect of development or tool can be posted in the General chat forum.

    By following these guidelines we make sure that the forums remain easy to read for everybody and also that the right people can find your post to answer it.

MSFS Fixing turboprop behavior

TLDR: I would like to fix the behavior of the engines of the King Air 350. Do any of you guys have tips regarding how to do it, wich ressources i should read.

Hi, i have developped somewhat of a love with the king air 350 of the basegame and fly it a few hours a week with great joy. However there are a few downsides to the current state of the airplane simulation. Among them is the behavior of the engines.
Just to state a few:
  • - torque increasing with altitude
  • - N1 inertia way too high
  • - prop feathering not affecting fuel burn
(As reference here is a link to a youtube video where a irl king air pilot reviews the sim's one:

From my research in the sdk i did not really find what i was hoping for regarding modding the engine behavior. It seems like there is no proper way to outright override the functions that govern engine thrust with a new one. From what i understand at this point the config file will definetly not be enough to reach my objective. Hell, i hardly found a viable explanation of how the engine simulation works behind the scene in order to output the thrust wich would have been helpful for clarifying the config file parameters.

In general, my plan would have been to write a simulation of the turboprop that would take in the parameters from the game (positions of levers, air temp, air density, humidity...) and send back to the game the thrust value. If the reader has ever written a mod into minecraft, that is the basic way to do it. You create a .js that access the packages of the game and change values as your needs.

To this date, i have not found the way to access those values from the sdk. I do expect if there is a ressource out there with this kind of information i should find the rest that i need in the vicinity. Here is where i need your help.
If you have a idea of how to pull this off, know ressources i should be looking into, i would be glad to read your answers. If you have any comments please go ahead.
Thanks for your time.

P.S: English is not my first language, i propably made a lot of mistakes and i am sorry for it. I was not sure this is the right forum to post in, sorry if it is'nt.

Roy Holmes

Resource contributor
The engine behaviour has changed with MSFS compared to how it worked for years in FS,FSX and P3D. There is no information in the SDK about this and I am amazed they changed from the FS method which worked really well for jets and adequately for turbo props. Right now I'm working on flight testing a MSFS version of a P3D/FSX light fighter. I have the performance documentation and in FS it is very close to the specification. So far it is a long way out in MSFS and I'm doubtful I can get it accurate.
The old method used corrected values which is a standard way to process flight test data. There is a paper in page 11 of the resources by Roy Holmes which describes the method that has been used for years in the previous microsoft simulator but Asobo are working to make the engine performance more realistic and actually ruining it so far.
There is a paper in page 11 of the resources by Roy Holmes
Thanks for the reply, this ressource will be useful.

However, even with the light brought by this ressource i still have'nt found information on how i would link my calculations to the game. To be clear, i am hoping to find a way to implement my simulation of the engine at the software level instead of changing the behavior trough the config file. I know there is some mods that use this kind of modding to implement behavior not anticipated by asobo. Working title cj4 and flybywire a320nx are good examples of that.

So essentially:
How do i write source code that interact with the game? Where is the documentation for those interfaces? (i have not found it yet)
Thanks again.