MSFS Aerobatic aircraft

CBris · 12 May 2022

Is there a skilled coder around here who is maybe working on a set of flight dynamics for an(y) aerobatic piston engined performer. I have been on a couple of beta test teams for msfs aircraft of this genre and all I get is "this is too difficult in msfs" or "Asobo have shut the door and thrown away the key to the possibilities of editing flight dynamics".

OK, it might be a bit harsh to bash addon devs, but I seem to remember that even a non-geek like myself could tweak the FDE in FSX and prior. There was even a software tool (anyone remember that?). Besides - we even had a godess of FD tweaking in Pam Brooker.

If you are wondering what I am expecting of aerobatics in msfs, then search YouTube for the likes of Jurgis Kairys, Castor Fantobas, Richard Goode, Anna Kapenina et al.

I am a bit too old a dog to consider learning new tricks, but by the gods, I will if I really really have to - and if I can find a well structured "FDE for Dummies" book.

Just asking... I'd welcome anyone already working in this field to share - even PM and NDA.

Ronald · 12 May 2022

Hello CBris,
1 - First things first: I have not yet taken a look at the MSFS2020 SDK. I just got started toying around with the old FSX-"SDK", but do have over 40 years of experience behind the keyboard
and yes "I can code a little" (busy re-learning C and C++ right now) and I read / decode somebody elses source-codes too.

Is there a skilled coder around here who is maybe working on a set of flight dynamics for an(y) aerobatic piston engined performer.

2 - From the postings I've seen here on this forum, 4 people come into my mind:
Misho has extended the internal FSX flightdynamics-model straight into space itself:
-https://www.fsdeveloper.com/forum/members/misho.934/

Fred - was able to successfully rewrite the FS flightmodel to get better as simulation helicopters. "TOTAL HELICOPTER REALISM"
-https://www.fsdeveloper.com/forum/threads/helicopter-total-realism-1-0-htr-released.18907/

Roy has also a lot of experience in flight-dynamics matter:
-https://www.fsdeveloper.com/forum/members/roy-holmes.10000/

Dai has in-depth coding knowledge and gauge development skills
- https://www.fsdeveloper.com/forum/members/dragonflightdesign.3563/

NOTE: There may be more people but not that I know of right now.

TIP Look around in the Flight Dynamics section to see who else if active in there:
-https://www.fsdeveloper.com/forum/forums/flight-dynamics.65/

[/quote]I have been on a couple of beta test teams for msfs aircraft of this genre and all I get is "this is too difficult in msfs" [/quote]
3 - Lets be totally honest shall we? "Flight Dynamics Modeling" as in:
"Nasa Flight Dynamics" website
-https://www.grc.nasa.gov/www/k-12/UEET/StudentSite/dynamicsofflight.html

"Derivation and definition of a linear aircraft model"
-https://www.nasa.gov/centers/dryden/pdf/88104main_H-1391.pdf

NASA - "Modeling flight"
- https://www.nasa.gov/pdf/483000main_ModelingFlight.pdf

is not your everyday computer_coding challenge right? To me this challenge does require:
A - A higher degree of mathematical - and aeronautical_level insights (which not everyone has or is willing to learn)
B - Knowledge of near-real-time computing skills (not some ordinary gui-form + button-pushing default template type-of-coding project)
C - A lot of in_depth algorithmic and computer coding skills and experience to implement:
against often - let say this as boldy as I can - "Highly unstructured / ill-documented (if any documentation exist at all) flight-simulator "API's".
In all these years inside the MSFS-FS ecosystem I have not been able to find a (decent noob-level) tutorial on how to get started creating a totally new flight-dynamics model from scratch, absolute zero.
After examining all still downloadbale and thus available FSx-SDK's (from fs98 to fsx) they do not contain any well-documented materials on how to flight-model an aircraft.
To me personally it feels like Microsoft does not want others to be able to create new (and much better . more accurate) flight-models into their simulators at all.

4 - I think the best change your have on finding the people you need is currently inside the :
- X-plane community (which allows swap able flight model modules by design)
-https://www.x-plane.com/

- Flight Gear Community which comes with a swapable flight-dynamics design
It is totally open source, so hack it and create your own flight-model inside it
-https://www.flightgear.org/
-https://wiki.flightgear.org/Flight_Dynamics_Model

to be continued below...

Ronald · 12 May 2022

or "Asobo have shut the door and thrown away the key to the possibilities of editing flight dynamics".

5 - Then the next question arises: Why is this happening? Who benefits from this shut-door?
MSFS2020 seems to be totally rewritten from scratch, so perhaps de Asobo Developer team members are still busy understanding, developing and finetuning their own internal knowledge of real-world
(not XBOX style arcade-level) flight-dynamics models? But to be absolute sure about that, you have to ask "the MSFS2020 experts" here who already are over their head inside the current version of the Asobo's MSFS2020 materials.

Thread worth reading on the Asobo forums:
-https://forums.flightsimulator.com/...stic-or-do-we-need-a-completly-rewrite/445076
- https://forums.flightsimulator.com/t/msfs2020-flight-model-comparison/452146/3
- [url] Other MSFS2020 threads worth.../11/msfs2020-improved-flight-physics-v15.html

Video on MSFS2020 flight model
-

..
-

..
and be sure to check out Microsoft own Developers videos too about this subject.
- https://www.youtube.com/c/MicrosoftFlightSimulator/playlists

OK, it might be a bit harsh to bash addon devs, but I seem to remember that even a non-geek like myself could tweak the FDE in FSX and prior.

6 - Now that is a good start isn't CBris? "Become that change you want to see in this flyght-dynamics eco-system" (c) Mahatma Gandhi
You already seem to have the knowledge inside you. All you now need - right now - is to find (new and innovative) ways of getting it back into MSFS2020 and you are good to go right?

There was even a software tool (anyone remember that?). Besides - we even had a goddess of FD tweaking in Pam Brooker.

7 - I never heared of Pam before, so I started a search and found these articles:
- https://www.flightsim.com/vbfs/content.php?13624-Low-and-Slow-II-Sopwith-Camel/view/2 - 2013
- http://www.perfectflight.cloud/2018...243j-dynamics-of-nonlinear-systems-fall-2003/
-https://ocw.mit.edu/courses/16-886-air-transportation-systems-architecting-spring-2004/
-https://ocw.mit.edu/courses/16-333-aircraft-stability-and-control-fall-2004/
-https://ocw.mit.edu/courses/16-885j-aircraft-systems-engineering-fall-2004/
-https://ocw.mit.edu/courses/16-885j-aircraft-systems-engineering-fall-2005/
-https://ocw.mit.edu/courses/16-333-aircraft-stability-and-control-fall-2004/
So what is keeping you from learning "new tricks"for absolute free?

They also have a TON on computer programming topic too
- https://ocw.mit.edu/search/?q=computer

If you are wondering what I am expecting of aerobatics in msfs, then search YouTube for the likes of Jurgis Kairys, Castor Fantobas, Richard Goode, Anna Kapenina et al.

LOL Thanks for the video suggestions Cbris. I've seen nice materials, I've enjoyed them.

I am a bit too old a dog to consider learning new tricks, but by the gods, I will if I really really have to - and if I can find a well structured "FDE for Dummies" book.

Who are you kidding Cbris? "I sense that flight_dynamics dev-force in you" and when fuelled with enough passion and the right materials, I 'm pretty sure you can accomplish this task yourself 100 over 100.
And as long as that (with all respect) "old dog" is alive, above ground, breathing, bashing and barking, He is still is able can learn new tricks right?
"Where there is a Will, fueled by passion and the Right Stuff There are new ways to be found, new waypoints to be set, and new destination to be reached" (c? - author unknown)

Just asking... I'd welcome anyone already working in this field to share - even PM and NDA.

Just replying.... to what I read and sense between your lines CBris. I hope that my reply is somehow valuable to you in some way

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Ronald · 13 May 2022

ADDITION: I just found a nice gathering of flight-dynamics guru's over here at the JSB-SIM community:
-http://jsbsim.sourceforge.net/index.html - homepage
-http://jsbsim.sourceforge.net/JSBSim/index.html -

They are currently working on a "Aircraft Development Toolkit for Outerra"
-https://forum.outerra.com/index.php?topic=3240.msg35149#msg35149
I guess these are the type of individuals you want to get in contact with CBirs. Am I right so far?

MSFS2020 forum discussion on their internal flight-model:
- https://forums.flightsimulator.com/t/physics-model-needs-an-overhaul-asap/350623

Asobo - MSFS2020 Flight-model SDK pages (in case you want get started yourself)
-https://docs.flightsimulator.com/html/Samples_And_Tutorials/Primers/Flight_Model_Physics.htm

AVSIM forums - Msfs2020 flight model discussion threads (worth reading)
-https://www.avsim.com/forums/topic/578988-still-worried-about-the-flight-model-how-planes-move/
-[urlhttps://www.avsim.com/forums/topic/601526-msfs-has-the-most-advanced-flight-model/[/url]

3rd party article about the MSFS2020 flight model (by a real-world pilot):
-https://medium.com/swlh/microsoft-flight-simulator-2020-no-competition-for-x-plane-11-e7cd0a1d121e

EDIT: Found a new thread on the flightmodel on the MSFS2020 forum:
"All that is wrong with the MSFS Flight Model (Inertia, Stalling, Pitch Authority, Trim & Sensitivity) "
-https://forums.flightsimulator.com/...lling-pitch-authority-trim-sensitivity/379936

Enjoy

CBris · 17 May 2022

Good Lord! That is a load of information to digest - many thanks Ronald!

I will generalise a bit here and say that I am following the fora at flightsimulator.com - that's a given. Despite all claims by many contributors saying that they love the sim I can tell that most "pro asobo" commentators do not appear to have a clue about real flying, except possibly that they have sat in a 737 as a passenger when going on holidays. I do allow myself such a statement because I have realworld experience of flying as P1 with aerobatics experience - OK, gliders, so? I also have "stick time" with anything the British army flew in the 70's and 80's including some tutoring by a Blue Eagles pilot.

Yes. MSFS is great as far as eye candy goes. I do love it. I am just saddened that it cannot even match flight dynamics performance with FSX. Like flying inverted through the arches of the Eiffel Tower, push stick forward to climb out of the inverted flight and do three vertical aeleron rolls followed by tipping to level position, hitting full power and rudder and literally doing a flat/horizontal Lomcevok.

Ah well, one day

Lagaffe · 17 May 2022

Ah, a man who think like me

I'm happy

Ronald · 19 May 2022

Good Lord! That is a load of information to digest - many thanks Ronald!

1 - Your welcome Cbris, It was a lot of fun diving into this material for me too.

I will generalize a bit here and say that I am following the fora at flightsimulator.com - that's a given.

2 - Manufacturer forums are a great resource to read, since one can often find the most heated discussions over here.
But don't forget to look at the other forum out there like to get a 360-view on the matter:
- https://www.avsim.com/forums/
- https://www.flightsim.com/vbfs/forum.php
- https://forum.flyawaysimulation.com/
- https://forum.simflight.com/

Despite all claims by many contributors saying that they love the sim I can tell that most "pro asobo" commentators do not appear to have a clue about real flying, except possibly that they have sat in a 737 as a passenger when going on holidays.

3 - I agreed on that point completely with you Cbris...

I do allow myself such a statement because I have real-world experience of flying as P1 with aerobatics experience - OK, gliders, so? I also have "stick time" with anything the British army flew in the 70's and 80's including some tutoring by a Blue Eagles pilot.

4 - Great so you have been a real-world pilot yourself, awesome! may I ask: What got you started in flying and which birds did you fly for the Britisch Army?

Yes. MSFS is great as far as eye candy goes. I do love it. I am just saddened that it cannot even match flight dynamics performance with FSX.

5 - Browsing through Asobo Studios (games) history over here:
-https://www.asobostudio.com/games
I guess they had to start from scratch doing something they have never ever done before - modeling physically accurate real-world matching flight_dynamics, which feel like the real thing.

By the way, this is a nice thread/poll to read what the global flightsim community thinks about Asobo Studios
-https://www.avsim.com/forums/topic/610908-asobo-is-the-greatest-flightsim-company-in-history/

Like flying inverted through the arches of the Eiffel Tower, push stick forward to climb out of the inverted flight and do three vertical aileron rolls followed by tipping to level position, hitting full power and rudder and literally doing a flat/horizontal Lomcevok.

6 - I guess to experience that kind of real-world aerobatic feeling inside a flight-simulator, your best choice would be:
Open Source flightsim: "FligtGear" - which (also) uses the "LaRCsim flight model" from Nasa (and has swap-able flight_dynamics_engines)
-https://www.flightgear.org/
-https://wiki.flightgear.org/LaRCsim

Laminar Reasearch's "XPlane" - which has been officially been approved by the FAA to be used in hardware-based flight-simulator-setups
-https://realsimgear.com/blogs/news/faa-approved-flight-simulators-guide
-https://www.gleimaviation.com/2018/10/19/meet-the-brains-behind-xplane-and-x-force-pc/

Or even Lockheed Martin's "Prepar3d", since this sim has naturally evolved from the old Microsoft FSX/ESP code base...

B21-soaring · 24 May 2022

I've spent hundreds of hours programming MSFS flight models for gliders (and I've done the same in X-Plane and FSX). MSFS isn't "rewritten from scratch", in particular Asobo carried over the flight model from FSX/FS2004/FS2002 and has been trying to 'improve' that ever since, starting with removing a huge swathe of hard-coded parameters in preference to deriving more of the flight model from the physical characteristics of the plane. Asobo put quite a lot into MSFS to help developers migrate their FSX aircraft but I suspect they now regret this. The challenge with MSFS flight model development is (unsurprisingly) getting to grips with what combination of parameters you should adjust to get the flight behaviour you want. I'd suggest caution in a couple of things: (1) using technical advice based purely on FSX - so much has changed in MSFS that is often outdated and (2) getting answers on (e.g.) "how do I adjust the stall speed" with "here's how the aerodynamics of stalls works" which misses the real challenge of which MSFS parameters do what (simple question - which parameter change in MSFS flight_model.cfg most affects the stall speed?)

As a suggestion, you could download the freeware LS4 glider from flightsim.to and try aerobatics in that. I know the real aircraft isn't rated for aerobatics but the package uses the MSFS "modern" flight model. It's not bad for a sim aircraft and works for limited aerobatics (caveat: I programmed the flight model). You could pretend the glider is a Swift or a Fox and see if you can tweak the flight_model.cfg to get the aerobatic performance you want which would be useful experience on anything else. IMHO flight model tuning with a glider is not a bad place to start as you get to see any underlying flightmodel issues before you add the engine.

Ronald · 24 May 2022

MSFS isn't "rewritten from scratch", in particular Asobo carried over the flight model from FSX/FS2004/FS2002 and has been trying to 'improve' that ever since,
starting with removing a huge swathe of hard-coded parameters in preference to deriving more of the flight model from the physical characteristics of the plane.

1 - Aha, that is why I still find old Microsoft ESP/FSX fragments inside their SDK documentation.

2 - Thanks for sharing your insights B21-soaring. I just found this video from on the Milviz GoogleTube channel about the current state of "MSFS2020 internals".
-

This video provides a great insights on what kind of challenges developers run into when publishing their product on MSFS2020.