Models= 1% realism? Is this right?

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OleBoy

Charter Member 2015
I'm not entirely sure if the topic makes sense or not. I read (I think) about some CFS2 models that had 1% realism in flight dynamics? Or something on those lines anyway.

Are FS2004 models capable of this realism also?

If so, can anyone direct me to those types? I would like to try these type.
 
1% was/is the goal of the developers to produce FM's that fly within 1% of their real world specs. It's more of an ongoing decoding process rather than a statement that they actually fly within 1%.
Since there are not really significant differences in the aero files amongst CFS2/CFS3/FS9/FSX the same goal can be applied to any of the FS sims.
Homepage of the 1% devs:
http://avhistory.org/communityserver/default.aspx
 
Thank you for the response Mathias. So then you are saying this is a goal, or standard. I see.

I was looking at the models there. There are a few...lol. These CFS3 models, are they compatible with fs2004, or no?
 
CFS 3 models are not compatible with the other versions of CFS or FS. That was a new direction that MS went and it died with CFS 4.

As for the 1% flight models, let's just say that the developers and I had some pretty heavy arguments about them. Although in hindsight, some of the CFS 2 ones do seem to work well in FS9.
 
Willy said:
CFS 3 models are not compatible with the other versions of CFS or FS.

As for the 1% flight models, Although in hindsight, some of the CFS 2 ones do seem to work well in FS9.
Click to expand...


That's what I heard. But had to ask to be sure.

I'd like to try some of the CFS2 that are compatible examples.
 
Remember that the FM's are coded for the specific sim, CFS2 or 3. Whilst they may work acceptably in FS9/X there may be a few problems. I know that some CFS2 files (not 1% ones specifically,I haven't even thought to try them) have CoG/balance problems(nose heavy) when used in FS9 when they were perfectly balanced in CFS2. Also the gear and flap drag can cause headaches.

Mr Beckwiths FM's follow a similar goal, IIRC he was involved in the 1% team way back when... His Airwrench and FM workbooks are a good starting point for creating a semi decent FM, for a better result, use a Sparks FM when it comes with a plane.

Other FM modellers may use similar methods or even his tools, Henry, Fleiger, etc.

Jamie
 
It's worth remembering that while having a flight model that performs within 1% of the plane's specifications is a fine goal for a modeler, in the real world there's more difference than that between the performance of individual aircraft of the same type and model. And that's right out the door of the manufacturing plant. Add the variations that arise due to the unique wear and tear on individual planes and the differences become quite a bit larger.

Not to mention that a plane's official specifications often contain a significant dose of creative writing by the manufacturer's marketing department...
 
Hi,

Seem's to me .. I never readed very heated discussions about flight models concerning FS2004 or FSX.
Usually FS users are happy when they can take off cruise and landing .. respecting more or less the performances of a plane.
For the combatsim's it's a other story as they have more interactivity (offline with the AI planes and online with the human pilots)
This is ton's of heated discussions about flights models (and damages models) for good or bad reasons.

XMAS_GS004.gif
 
Claudius,

I hear you. Remember many a heated debate in the combat forums about this, everyone had different ideas about EVERYTHING!! I think where the 1% planes worked so well was online and levelled the playing-field for all players using them, much like using stock planes only.

Jamie
 
Mick said:
It's worth remembering that while having a flight model that performs within 1% of the plane's specifications is a fine goal for a modeler, in the real world there's more difference than that between the performance of individual aircraft of the same type and model. And that's right out the door of the manufacturing plant. Add the variations that arise due to the unique wear and tear on individual planes and the differences become quite a bit larger.

Not to mention that a plane's official specifications often contain a significant dose of creative writing by the manufacturer's marketing department...
Click to expand...

You could even make the point about an individual airframe as it ages and leaks and things wear. Add a few scab patches and parasitic drag from seals not making and doors and hatches out of rig and you have a a reduced top speed, higher fuel flows, increased zero fuel weight, and reduced ranges. Even a coat of paint can effect performance. I seem to remember our CAF Herks losing a couple of knots due to the matte paint they applied in the late 80s.

Regards, Rob :ernae:
 
The goal was to replicate the performance of real world aircraft using mfgr's or service test data. As a practical matter it is possible to closely replicate the maximum speeds at perhaps two points, Sl and some critical altitude at which the engine power was restricted by super/turbo charger output. Staged supercgharged engines had a bit of a jaged "curve" of power vrs altitude as the various blowers were engaged.

Handling is a much more subjective and difficult area to replicate, needing much specific aircraft knowledge and much fine tuning of the air file. I did the air files for the SOH Corsars of several years ago and they do pretty closely replicate the aircraft perhormance as I can glean from the information available. Though FS9 planes they fly well in FSX and were actually developed (flight wise) in the various FSX beta versions as they spooled forth. The SOH A26 and the Uvier DC2 also have pretty close to real world performance. Many others exist as well.

Cheers: T
 
fliger747 said:
The goal was to replicate the performance of real world aircraft using mfgr's or service test data...

Handling is a much more subjective and difficult area to replicate, needing much specific aircraft knowledge and much fine tuning of the air file. I did the air files for the SOH Corsairs of several years ago and they do pretty closely replicate the aircraft performance as I can glean from the information available... The SOH A26 and the Uvier DC2 also have pretty close to real world performance. Many others exist as well.
Cheers: T
Click to expand...

Amen T!

Reflect that in the real world the engineering is written first -which describes the overall structure - then the shape is made from those specs, then the two are tweaked to make it work. In FS the modeler tries to replicate a known design image (because that's what the user is going to see first) and then try to make it match what are sometimes vague specifications (or hearsay) to make it appeal to, but not dismay users who are generally not engineering test pilots.

Everyone's happy... until you fly 'by the book' or start comparing performance to multiple historical records (as we have been doing in the various multiplayer events in the last couple of years.) and other models of the same aircraft. With that kind of scrutiny the 'little oversights' start to become apparent - not to the point of making it a "bad model" but pointing out the inaccuracies.

It also depends on how much data is available. I've had discussions for years with people who say: "Well, such and such reference says the max speed is 400MPH and the range is 2000 miles" -- and think that the plane really will go 2000 miles at 400MPH. Then they get a high-quality FS aircraft that is modeled to proper technical data and complain that it won't live up to their belief.

There lies the good and bad of MSFS models. I'll say that modelers overall are conscientious and dedicated, but since the first perception of a model is it's appearance that's often where the first huge amount of effort goes. After all those hours he (they) then have to dig into tons of research -which just may NOT be available- to get not only the "Wiki-style" data (5 lines of "performance data") but ideally, engineering reports from which to model the flight dynamics -that's an art in itself. If he's not a student of aerodynamics there's a possibility of (throwing up hands, tearing hair) getting something 'close' or 'reasonable' that will fit the user's basic needs and quickly moving on to the textures. (Like the 45,000# helicopter that uses a Jet Ranger airfile! or Ito-san's beautiful visual models where he willingly admitted he didn't care about the realism of the flight model as long as it flew in an appealing way)

No wonder a lot of the payware (and some of the most excellent freeware) is done by teams who can have a dedicated "FDE guy" etc.and want to be able to live up to that scrutiny. As well, the MSFS internal engine is pretty good but... it really was intended as a recreational emulation of flight, NOT a true aircraft simulator and so the tiny nuances of lift/drag/thrust/weight are not as precisely/comprehensively replicated as the software running a $40M full-motion sim. That FS modelers can even dream of getting within 1% amazes me, and doubly astounds me when they achieve it. Those are the models that I fly when I want to enjoy the whole Flight Sim Experience... the others I happily keep around for when I want to bore holes in the LCD sky without really worrying about the details.

Personally, I can't imagine the time and dedication it takes to make an accurate visual model, then build the FDE to within 1% of "real", and texture it to stave off the nitpickers and put it up for sale or download with one's name attached. I'm just plain glad we have those who can do it.

Rob
 
I second that Sir-Gal. Adding of course that since the beginning of flight sim, which was truly intended as a great pastime there has been the tendency to live up to the name "As Real As It Gets".

The passion involved is incredible, which has seen great results, and has brought out the good and bad sides of flight sim development through the advent of it's users, (Rivet Counters causing the resignation of developers from flightsim), as an example.

Regarding the reality of flight sim, it can be said that it is everything we make of it and a whole lot of fun to boot. I say hats off to all who have added to this reality and who take us to new heights in the years to come.

For me - "It's As Real As It Continues To Get"...
 
Hi Guys

My recommendation is avoid the old 2.xx flight models. For their time they were good, but compared to the modern 4.xx AvHistory FM’s they are junk. The 2.xx were created when Jerry was part of AvHistory, and if you like the way they fly head over to mudpond.org and get the tool to create them.

After Jerry left I decided that AvHistory needed a new direction and to ramp up the technology. See, I really want to know how the aircraft flies, not someone’s opinion how it flies. FS/CFS uses 6-DoF Equations of Motion (which is what all high end Sim’s use) so really our 2.xx approach to create Stability Derivatives was wrong. I decided to see what tools the aerospace community used for their sim’s. Unfortunately, $100,000 for time on a CFD terminal was a little more than I could afford for each flight model. But there was a public domain tool called DATCOM, which is still used to teach aerodynamics at the Universities. DATCOM is basically 4,000 pages of high-end math created by the aerospace community. So that started a 5-year journey (where have we heard that before) to develop a DATCOM based program to create 6 DoF Stability Derivatives for FS/CFS. Along the way I got to talk with some really smart people out there and enhance my program with their work. I really appreciate the time they and their students took to help.

So what makes it different? My interest is WW2 time frame aircraft. One problem is a lot of data for these aircraft was destroyed and doesn’t exist. What's the roll rate? How stable was it? What about stick forces? What about stall speeds? How much Lift/Drag do the flaps add? So all current tools fail right there. This is where the program shines. It can create all these Stability Derivatives. Not only the base Derivatives, but how they change with speed and AoA. So the end result models the aircraft throughout the entire flight envelope, not just one small part.

And the neat part is, it’s not someone’s opinion, there is a lot of science behind the data. And if there is a discrepancy, instead of he who yells loudest gets his way, we look at what the aircraft would need to meet the discrepancy. Maybe the nose shape of the aileron was different? Or the dynamic wake of the tail was different? Or spring tabs were used? Or even the length of the flight stick? The end result is our knowledge base for the aircraft increases.

If you want to do a comparison, Grab AirEd and open one of the CFS3 4.0.169 FM’s. First thing you’ll notice is every single parameter and table has data. Second you’ll notice we use the hi-res Stability Derivatives (sections 1539-1544). Third, we don’t use the MS arcade sections (1537-1538) for spins. Forth the change in lift models Reynolds Number and Mach effects. Fifth our lift models the characteristic double peak. Sixth we don’t use the arcade prop factor scalers (521-522) since we use the right data. Last, what you can’t see is we don’t use the Roskam tables everyone uses to determine MOI’s. We use a Class 2 Weight Analysis (thank you General Dynamics) because it’s important to know how a 500 turret in the nose and tail effects the MOI’s which Roskam doesn’t account for and it also allows us to calculate the Coupled MoI which you’ll not find any one else using. There is a lot more, but that would be bragging. :icon_lol:

Currently, there is only one FSX aircraft flying with an AvHistory Flight Model (http://www.classics-hangar.de/). There are quite a few bugs in the FSX flight equations that were a pain to work around.

Also for our WW2 research we are using the Strike Fighters series engine now. It’s the last of the retail sims using 6-DoF Flight Models (along with Eagle Dynamics). Everything else is some flavor of Arcade. Like FS/CFS if has some missing pieces, but the Dev is very friendly and continuing to evolve the series. And the AI is amazing with the tactics they use.

You may be able to convert the CFS3 4.0.169 flight models over to FS2004. Just remember the AIR file and Aircraft.cfg are matched sets and should always stay together. Also you’ll need to map Engine WEP to a key to access this power boost.

AvHistory :ernae:
 
Hi gregoryp!. Long time no see, but then I've stayed away from CFS 3 as well too.

I'd like to mess around with some of those latest FMs in FS9 and see how they work out. I'm assuming they're at the AvHistory website.
 
Somehow CFS 3 just never cut it with me. So at the point the AV history left CFS2 behind, I quit following their trail. It is possible to do much with the FSX flight engine. As a 20,000 plus hour pilot I feel I have some right to comment on this. That said, many work arounds are necessary, but much is possible. I have worked on flight dynamics for some planes that I have flown, but many I have not. Surprisingly more is sometimes possible in the freeware arena than the payware arena due to the freedom that working for free brings...

Thanks to all that have advanced the art over the years!

Cheers T
 
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