Propwash physics. The best ive seen in a sim!

[Slides 1,552]

Just now, Cyrex1984 said:

The flightmodel in mfs is closer to blade element theory than lookup tables, but its neither.

Yeah, DCS is more similar to MSFS in how it does FM

[jon b 2,047]

A truly fascinating discussion.

Perhaps it’s just a placebo effect but in the context of sd_flyer’s comments above about unloading the nose wheel...I’m finding I can replicate the technique for a soft/short field take off in the Cessnas much better than in any other sim I own.

That is to hold back pressure during the take off role to get the nose wheel off the soft ground ASAP let the aircraft get airborne prematurely then lower the nose to stay in ground effect while accelerating to an appropriate climb away speed. This simulator  does all of that perfectly and allows me to use the techniques I was taught bush flying in the Australian outback. I’m loving it, it’s bringing back great memories 

[L3m0n 56]

7 minutes ago, robert young said:

I don't have any prejudice or bias either way. If a flight physics system was invented in 1950 or 2050 it doesn't really matter to me. Your earlier post hinted that anyone not on board with the "new" physics is some kind of old fashioned stick in the mud, unwillling to change. 90% of the params in the "new" cfg files are just the old air file presented in a text form. There honestly is nothing much new at the moment. There might be in the future but there is really nothing that stands out as different - it is the individual tuning of each aircraft that is different. 

Wing flex is a graphical/3d animation and not (as yet) part of any flight model. That might change in the future and if it does that's excellent news.

At the moment you can tune both the Legacy and "Modern" flight models almost identically and no-one would see the difference. The modern version handles similar params in a slightly different way, so you need somewhat different values between the two to get a similar effect. I think if Asobo do implement their multiple lift points in the future then that's a different matter, and I'm all for that if it offers more scope.

You should read through the SDK. There is a section that is all about the FM and explains some of the requirements. Evidently MS wanted the new flight model to be compatible with the old one, so that a ported FSX aircraft would perform the same in normal flight. But the newer FM, basically using the same parameters as the old, would improve the FSX aircraft on the edge/near stall. 

The documentation gives a pretty good idea of how all this works although its not complete yet. There are also some obvious things that need to be added to the new FM but it already is estimating lift/drag across a ton of different points, something like 80 per wing.

[tweekz 2,165]

14 minutes ago, robert young said:

90% of the params in the "new" cfg files are just the old air file presented in a text form.

They might be. But that's not what matters. What matters is what the sim does with the data.

In legacy you had to provide all the aerodynamic data. With the new it takes only a few and calculates the aerodynmaic behavior based on those paramters + the shape of the aircraft. Those calculations also provide you with parameters that you would have had to investigate on your own in the old moldel.

So the new model is both more accessible and reproducable from a scientific point of view.

Edited September 3, 2020 by tweekz

[Slides 1,552]

Just now, L3m0n said:

The documentation gives a pretty good idea of how all this works although its not complete yet.

Been through the same debate with him before. He's too stubborn to listen to anyone else.

[Cyrex1984 176]

17 minutes ago, robert young said:

 

Wing flex is a graphical/3d animation and not (as yet) part of any flight model. That might change in the future and if it does that's excellent news.

 

So why does it respond dynamicly to the winds and updraft in alot of different behavior if its only one single 3D animation? And how do you know its only a 3D animation? Do you work at Asobo?

[Dillon 2,197]

1 hour ago, Slides said:

Agreed on the base flight model and it's abilities. A big improvement over FSX/P3D.

But of course there are some stuck in the past who can't accept the new reality and want to go back to the config files they're only familiar with. Some others are even in denial that the new FM is even different.

To me the new MSFS FM is in some ways very similar to the DCS External Flight Model, which uses a combination of lookup tables, parameterized equations and moments on the primary air foils.

 

I just hope some of those loud voices who can't accept how an aircraft feels as it flies through the air don't mess it up for everyone.

[tweekz 2,165]

13 minutes ago, Slides said:

Been through the same debate with him before. He's too stubborn to listen to anyone else.

I think it's a problem about wording.

@robert young talks about the cfg-file only and we talk about what the sim does with it.

I think it would cause some trouble if you actually tinker with parameters calculated by the "wind tunnel normalization". So you actually should not use it the legacy way.

Edited September 3, 2020 by tweekz

[jon b 2,047]

35 minutes ago, L3m0n said:

You should read through the SDK. There is a section that is all about the FM and explains some of the requirements

Is the SDK like a PDF you can download and read? I’d love to learn more about the flight modelling, I don’t do any tweaking or anything like that, I’m just interested.

[L3m0n 56]

7 minutes ago, jon b said:

Is the SDK like a PDF you can download and read? I’d love to learn more about the flight modelling, I don’t do any tweaking or anything like that, I’m just interested.

The documentation is a bunch of html files.

https://forums.flightsimulator.com/t/how-to-getting-started-with-the-sdk-dev-mode/123241

[roi1862 602]

With all the being said, which i do not disagree, maybe someone with more experience can explain how come non of the GA aircraft needs a rudder input to stay coordinated at any stage/speed/altitude/rate of turn ? 

I got rudder pedals and flying mostly the Cessna and the Cub, i do not need any rudder input, the ball is almost perfectly centered all the time. 

Yes i got the life-like settings and modern flight physics.

[jon b 2,047]

@L3m0n Thank you🙂

[UAL4life 239]

Just wish they had wake turbulence 😕

[kerosene31 349]

26 minutes ago, roi1862 said:

With all the being said, which i do not disagree, maybe someone with more experience can explain how come non of the GA aircraft needs a rudder input to stay coordinated at any stage/speed/altitude/rate of turn ? 

I got rudder pedals and flying mostly the Cessna and the Cub, i do not need any rudder input, the ball is almost perfectly centered all the time. 

Yes i got the life-like settings and modern flight physics.

I get the exact same thing.  I never use my pedals other than to keep the aircraft on the centerline at takeoff and with a crosswind on landing.  It is like flight is auto coordinated all the time or something. 

[roi1862 602]

1 minute ago, kerosene31 said:

I get the exact same thing.  I never use my pedals other than to keep the aircraft on the centerline at takeoff and with a crosswind on landing.  It is like flight is auto coordinated all the time or something. 

Yep. I am surprised non of the more professional pilots here didn't mention it.