This is not correct LA. 1. The ground effect in MSFS is TOTALLY WRONG AN INCOMPLETE, I have proven this to you before;

I wasn't actually going for "ground effect". Just the flight modeling while still on the ground. L.Adamson

*******... guy's grow up, we are talking about simulators here made by human beings, they are BOTH FULLof errors and simplifications. Or is it just pilots that are this naive?

You're the MAN!!!! Just what I've been thinking for years!!!! Just so you know, I'm well aware that you've expressed the fact that X-Plane has required numerous work arounds, just as MSFS has. That's why I told Goram to see what you've wrote, when he asked for links. So thank you............as I've apprciated what you've done for X-Plane. Seriously! L.Adamson

Because it is from an engineering and aerodynamics point of view in most part of the subsonic envelope.The main reason is that FS is 1-dimensional, XP is 2-dimensional.If each individual aircraft isn't superior thats not the sims fault, but the shortcomings of the designer.

Ah shoot...................Still don't agree with that one. L.Adamson

Both flight simulators do not (and never will) accurately simulate flight aerodynamics. Because it is impossible to simulate (in the true sense of the word) motion on a two dimensional computer screen. Impossible. Arguments for and against either of these flight simulation platforms' FDE methods and engines are naive and futile. PC flight sims will always use a non-accuate method to simply present the absolute basic level of aerodynamics; by basic I mean things like; the action of an elevator control surface generally causing a lift or drop in altitude, the action of ailerons causing roll etc. beyond that ultra basic level of simulation..............forget it. The FSX method of look up tables is not accurate and the blade element theory in X-Plane is not accurate. The simulation in flight simulation is about procedure. That's limit of the simulation potential. The whole FDE element will always be limited to entertainment. So stop arguing, tame the egos, stop calling people arrogant when you're displaying such a heathly dose it yourself, and just celebrate the positive aspects that both of these platforms argue. Your arguments are circular, I think everyone has forgotten what the point ever even was, and it's all quite frankly tiring now. I love FSX and X-Plane but I use X-Plane 90% of the time because it offers some native features that are personally more valuable to me, and I'm able to operate it with much, much higher settings on my PC. (Eg... in FSX I can't really simulate weather because it just kills PC performance). In X-Plane I can run a modern airliner sim (like the marvelous FlyJSim Dash 8), or some nice GA (like Goran's Duchess), and have max autogen, loads of cloud layers, and generally high settings across the baord; this makes it a richer, broader flight sim experience. I do also believe that X-Plane's FDE feels more realistic, (bearing in mind everything I ranted above!). So it's X-Plane for me. But I still use FSX sometimes, for other things, like a wider range of add-ons aircraft.

The simulation in flight simulation is about procedure. That's limit of the simulation potential. The whole FDE element will always be limited to entertainment.

No.....................much of the point has been getting the flight dynamics closer to the real example. They improve all the time. To dismiss it as purely entertainment is short sighted L.Adamson

Both flight simulators do not (and never will) accurately simulate flight aerodynamics. Because it is impossible to simulate (in the true sense of the word) motion on a two dimensional computer screen. Impossible. Arguments for and against either of these flight simulation platforms' FDE methods and engines are naive and futile. PC flight sims will always use a non-accuate method to simply present the absolute basic level of aerodynamics; by basic I mean things like; the action of an elevator control surface generally causing a lift or drop in altitude, the action of ailerons causing roll etc. beyond that ultra basic level of simulation..............forget it. The FSX method of look up tables is not accurate and the blade element theory in X-Plane is not accurate.

That really IS shortsighted. Years ago, when I'd beta-test, I'd go up and do quick hits and releases on the yokes & sticks, just to see how the aircraft reacted in returning to neutral roll & beyond, then back to neutral stability. How long did it take, and did it even do it. Example: my RV is much diffferent that a Cessna, in this regard. This would be passed on to simulate. It was far beyond simple ups & downs with desktop controls. L.Adamson

Ah shoot...................Still don't agree with that one.

Well, you are not an engineer afaik, so you are forgiven

All the points you mentioned are a proof that XP is a nice engineering type approximation....something very useful if you design a new plane or if you want to use a new concept in plane design for an initial assessment but way too primitive to exactly simulate a certain plane.If Boeing isn't able to predict and calculate the wingbending moment of their brand new 747 with the most modern high performance computers, do you really think that x-plane can seriously predict and calculate the behaviour of a complete plane? 1. I know the saying that an airplane is a lot of parts flying in very close formation and they are justed kept from desintegrating by the ability of the pilot.But in a flight sim that tries to simulate a certain plane separate a C_m for nacelles, the fuselage are useless because it's actually not a formation of parts so the only thing that counts is the total Cm. Not only that calculating separate C_m is a waste of computing power, I severly doubt that x-plane calculates the interaction between the fuselage and the nacelles.

The computing power you are talking about is literally taking milli-frames from the sim. Every single object made in Planemaker has an affect on the flight model. AFAIK, x plane DOES calculate the interaction between the fuselage and nacelles. If I am interpreting what you are saying correctly. However, even if it doesn't, I know for sure that FSX doesn't. (Yes, I know, it can be programmed to...it can be programmed in X Plane too)

2. No, it's not about different prop designs, it's (at least) 12 tables you use for any prop you design.

It's providing tables. X Plane allows a specific prop's specifications to be used. FAR more accurate than tables. It still does not match up to what is capable in Airfoil Maker. It doesn't even come close. Any airfoil can be modified in Airfoil Maker or you can even create a custom airfoil from scratch. Airfoil Maker is able to take official aircraft manufacturer specifications and apply the properties in the simulator. I'm not talking about just the basics. I'm talking about specific airfoil details.

3. Why do you need the thickness ratio? Interestingly the earlier versions of x-plane didn't have that feature for a very simple reason....it's a value that's not needed. Austin implemented the feature only because x-plane used to draw a standard 15% thickness airfoil in x-plane which looked of course silly on a F-104. You have C_L C_d & C_m . Where's the need for the thickness entry except for the look of the plane?x-plane looks better than earlier with the correct thickness but it has no impact on the flight model.C_L and C_m tables are very similiar in FSX (tables 1546 and 1547). They are just not splited because they are already valid for 360deg AoA.BTW, FSX has 25! different tables to simulate compressibility for every needed control surface and their interactions.

FSX has 25 different tables to simulate compressability?X Plane has 9 999 (nine thousand, nine hundred and ninety nine) different compressability settings for each airfoil. Settings go from 0.000 to 9.999

4. Why do you want to import any airfoil in history? Does x-plane take into account if the wing is flush riveted, if there's a fuselage wing fillet? a bulge in the wing for the gear doors? There are already C_L etc...you need to adapt to a certain plane.

Actually, bulges and dents CAN be simulated in the fuselage and engine nacelles. And they DO have an effect on the flight model. How much of an effect? I'm not sure. I haven't modelled the bulges or dents. AFAIK, they cannot be made on the gear doors because the gear doors are a very simple mesh in the flight model that has no resolution to add bulges. But the fuselage AND engine nacelles can have bulges and/or dents modelled in them. FSX can not.Does FSX take into account if the wing is flush riveted, if there's a fuselage wing fillet? a bulge in the wing for the gear doors? Definitely not.

X-planes aim is to simulate (rather coarse) the airflow which it does quite ok and that's something FSX never could do.But that's a different target than FSX has. With FSX you have to change a lot of tables in the airfile and all their interaction to be able to build a replica of a certain plane but it is possible.In x-plane you can design a plane basically without the need to know the real planes characteristics because the blade element theory is sufficient for an approximation.There's no way to get away that cheap in FSX but if you know the plane very well FSX gives you all the tools to make a very realistic real world counterpart.Well, at least 99% of the multimillion dollar flightsims also use a table based simulation.

Anyone can throw in some numbers in Planemaker to get a plane to fly. Only a skilled developer can get an aircraft to fly by the numbers. Of course it's possible to get it to fly accurately. More-so than the rough flight model you speak of. If X plane was so limited, then more developers would not be expanding to it. They would stick to what they know. The fact they are getting a good idea of what IS possible, in a younger market, and willing to learn to make flight models all over again, that tells me plenty.

Again, x-plane is different and I really love the flow visualization and the flight path depiction but it's IMHO too primitive (not at least due to the lack of computing power) to allow an exact replica of a real plane as can be seen by the much more precise stall/spin design possible in FSX. But that's only the most visible part. Things like simulating the certain details like a tendency to dutch roll are also possible but that needs very precise tuning.

Bernt, you are fooling yourself if you think X Plane cannot simulate a precise turn and spin. The flight model is infinitely adjustable...even if it is with plug ins. PMDG chose not to model BASIC stalls because of FSX's limited framework. Never mind DEEP stalls. They even skipped the basics. They spent 3-4 years on that thing. Why not spend a few more weeks/months to get it to stall right if it's so easy?_____________________________________________________________________________________________________________________________________________________________________In saying all this, we can always go back and forth by saying "But it can be programmed in FSX!" Well, of course it can. You could also make an entirely new flight sim that does simulate all this correctly. It's all about how far you want to take it. Morten has provided proof that X Planes core flight model is "better" (I don't like using the word superior). I have also provided proof with statements backed up with screenshots. Even Ben Supnik has jumped in. (for those that don't know, he's Austin's programmer, so even Morten will bow to his knowledge). The FSX supporters keep coming forward and start asking "But can X Plane model the rivets on the fuselage or the cracks/chips in the props??" Well, no. THAT would take a super computer to run and the resultant effect would be extremely minimal. The friction c-efficient can be adjusted to simulate the extra drag created by the rivets, but that's guesswork. BUT, FSX can't do it either so the point is dismissed. We're comparing what's available. And X Plane has far more tools and accuracy than FSX does.

That really IS shortsighted. Years ago, when I'd beta-test, I'd go up and do quick hits and releases on the yokes & sticks, just to see how the aircraft reacted in returning to neutral roll & beyond, then back to neutral stability. How long did it take, and did it even do it. Example: my RV is much diffferent that a Cessna, in this regard. This would be passed on to simulate. It was far beyond simple ups & downs with desktop controls. L.Adamson

I wasn't suggesting that the two sims only simulate basic control surface effects, just that they don't truly simulate the level of depth that you've gone to in this debate. With all due respect, the debate seems to be more about personal point scoring and semantics, and what I was suggesting was that there are no absolutes in either sim. There is no 'correct answer' with regards to simulating aerodynamic flight, whereas (linking in with what I said about procedural simulation) there can be a wholly 'correct' simulation of something like an engine start sequence. You strike me as someone to whom being right is more important than anything else. Having your knowledge and experience validated, being respected etc, and my point is that you won't achieve that in this debate, because no flight simulator can ever claim to have discovered/applied correct aerodynamic flight simulation.

You strike me as someone to whom being right is more important than anything else. Having your knowledge and experience validated, being respected etc, and my point is that you won't achieve that in this debate, because no flight simulator can ever claim to have discovered/applied correct aerodynamic flight simulation.

Actually......................I'm still remaining quite neutral regarding X-Plane versus FSX. I have both. If you've read more of my posts, you'd see that. I do not care about "brownie points" on a sim forum, even though I've used desktop sims since the invention. According to members of the AOPA, I'm also a cowboy type with a Harley stigma for owning a Van's RV. No respect there either. No respect on student pilot forums because I like GPS. Old instructors who hover over those boards are still into radio nav. L.Adamson

Looks like even Bernt (bstolle) wasn't this religious about FS9/X a few years ago either,so that must have come later (with the $?) http://www.flightsim...odel-sufficient (just kidding Bernt )

I don't know why you quote a 5 year old posting that was written when not even a full FSX version was available, let alone SP2.How bored were you to dig out that old posting?FYI I still make more freeware than payware FDs and with the few dollars I get I'm at least able to enlarge my collection of rather expensive documents from the AIAA etc to achieve even more precise FDs in the future....for FSX and later on FLIGHT of course...

I don't know why you quote a 5 year old posting that was written when not even a full FSX version was available, let alone SP2.How bored were you to dig out that old posting?

It's called irony my friend, something you apparently don't have a lot of.You should not take flightsims - or yourself that serious all the time But since you ask, came across it searching for FS developers forums (not you)Spent a couple of hours reading developers notes on FS9/X FD. Will save it for the next debate, to big a can of worms.

It's called irony my friend, something you apparently don't have a lot of.You should not take flightsims - or yourself that serious all the time But since you ask, came across it searching for FS developers forums (not you)Spent a couple of hours reading developers notes on FS9/X FD. Will save it for the next debate, to big a can of worms.

Sierra's Pro-Pilot was super, and MSFS stunk. That was back in 1997-98...............of course. L.Adamson

Actually, bulges and dents CAN be simulated in the fuselage and engine nacelles. And they DO have an effect on the flight model.

How are they simulated and how do they affect the flight model?

How are they simulated and how do they affect the flight model?

EVERYTHING that is made in Planemaker determines how the aircraft will fly in sim. When making a flight model in Planemaker, a developer almost always starts with the aircraft shape. It's broken down into several sections. Fuselage, airfoils, gear doors, landing gear, etc. The fuselage is made up of several sections. Up to 20 can be used. These sections are like cross sections and have adjustable points on them to make a round fuselage (Airliner) or a GA fuselage (more square). A point can be pushed in or pulled out and x planes flight model recognizes this and drag is produced accordingly. This drag is visible when turning on X Planes aerodynamics visuals in sim. They are represented simply by flowing lines of different colors. Green lines represent smooth airflow, Orange represent disrupting airflow, Red represents rough airflow.Because of this, VOR aerials, COMM antennas, etc...when modelled in Planemaker, all affect the flight model to some degree when in sim.I'll try to get a screenshot up sometime today or tomorrow.I have a perfect example of a Hawker 4000 I'm making and the landing gear wasn't modelled correctly in Planemaker. One wheel actually goes through the wing and can be seen on the top side of the wing. There are a bunch of red lines around the protruding wheel. The other wheel is in the correct position and as a result, the aircraft is yawing to one side because of the drag.