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Guest Ron Freimuth

FSEdit does

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I have an aircraft that does something that I don't like( regarding the way in which it rolls) -- so I put on my nice new and shiny aircraft designer cap, read up some stuff on the Internet about aircraft design and decide to alter the Dihedral and Roll MOI for this particular aircraft and see what happens. (it's called Trial and Error).So I make some significant changes to these figures in the Aircraft.cfg file using Notepad and nothing happens!! No changes to the aircrafts' dynamics is apparent!.Reading the Aircraft package SDK , it basically says that sometimes you have to use FSedit rather than just Notepad to make some changes (I agree with you here, Father Bill!) So I make the changes using Fsedit -- and BINGO!! - my aeronautical theories are validated and the aircraft does what I want ! BUT !!!- I then discover that it starts to do things that I don't want and are unassociated with my changes (roll and bank performance) - all of a sudden the aircraft is flying twice as fast as it should and I have "overspeed " warnings.Hmm? I have compared the new aircraft.cfg file with the new one and can see nothing to cause this.Bowing to superior and more experienced designers , I await your advice and condescension. :)Barry

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I have done extensive testing of my ultralight a/c to develop its flight characteristics. This is naturally because I have no specifications from the manufacturer (me!) to go by. I use a variety of sources on existing and historic ultralights as my guide along with inputting the dimensions of my a/c, wings, control surfaces into FS Ed. Same for the engine using published specs for a Rotax.But enough of that.The point is that FS is very buggy when changes are being "driven" by FS Ed (when you select "fly this aircraft" with FS and FS Ed open after making changes). I often find that I must save my changes, close FS Ed, close FS2002, then restart it for my a/c to make the changes work. I have also seen the uncontrollable acceleration and other problems after making changes. I learned this by trail and error suspecting that some sim values were not getting updated or only partially updated, I closed the sim and restarted to see my a/c was stable again.[i forgot to add, when you are switching back and forth between a/c a lot the a/c can become subtly damaged without your realizing it. Going from the Cessna to an ultralight can result in initial high speeds. This can damage the flaps, etc. cause the a/c to behave strangely until FS is reset. Even between different wing configurations and models of engine it can cause extreme differences on the same basic a/c.]During testing I often have spectacular crashes and amazing spin-dives into terrain while tweaking the center of gravity (I can only guesstimate this without any specs). It is amazing what small changes to CoG will do. Crashes can really break things in the aircraft, so I restart FS to get a "clean" air model after a crash.Even when switching aircraft or resetting the flight I find that settings or damage done can linger.Always be ready to assume that FS is failing to update values. Remember, software often caches data for efficiency and there can be problems with one hand not knowing what the other is doing, etc. I've had FS Ed repeatedly trash my panel.cfg files, deleting whole sections of gauges I had placed. Sounds familiar? Windows anyone?Steve

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So what does one do? Using Notepad alone to edit the aircraft.cfg file doesn't work -- FsEdit ruins the airfile by doing strange things, I downloaded the Abacus FDE programme only to have it tell me that I don't have FS2000 ( I have FS2002) and I can't find the latest version of Air ED.Thanks Barry

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AirEd152 - http://members.dsl-only.net/~eagle/Rename the attached file aired.ini and replace the aired.ini file that comes with AirEd152. Open the *.ini file for the credits of the person keeping it updated.You have to be careful what and how you do things in FS2002 Aircraft Editor. Once you have saved your file, you need to open both the *.air file with AirEd and the aircraft.cfg file with a text editor to ensure the proper things have been addressed.

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I think I got Air Ed 1.52 off of avsim. The home page in the read me does not seem to exist anymore. I use that to edit what FS Edit that came with FS2002 Pro cannot. I have not had FSEdit do anything strange that I recall.I am very new to this, so I may wrong.FS Edit writes the configuration data you enter into both the .air file and the aircraft.cfg file. Certain data goes into one and other data goes into the other as appropriate.Second, from what I have picked up on the message board is that certain settings that go into the .air file are mirrored in the aircraft.cfg file. This may so you can look a the values easily. But I gather that when the same setting appears in the .cfg file and the .air file that the setting in the .cfg takes precedent when the simulation is running.I am not clear if manual changes to values in the aircraft.cfg file using a text editor ever get written to the .air file.I have only briefly studied the FSEdit SDK so the answers may be contained in there. I highly recommend downloading this file if you are going to be modify flight dynamics. It has a lot of good information that the (old?) Aircraft Container SDK does not have.Okay, in the FDE flowchart, it says that the edited values are saved in aircraft.cfg and the aerodynamic coefficients are saved to the .air file. The coefficient values are apparently computed from the settings you enter in the FDE part of FS Ed. From this, it appears that the values are stored in aircraft.cfg for when you next edit the a/c.So if you make any changes to the flight dynamics values using Notepad, you need to open the a/c in FS Ed. then save it again for them to take effect (be computed and written to the .air file).

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>So if you make any changes to the flight dynamics values >using Notepad, you need to open the a/c in FS Ed. then save >it again for them to take effect (be computed and written to >the .air file). FSEdit is a flakey piece of bovine exhaust, as far as I can tell. I've never been successful in using it (it keeps crashing hard!), and lately the durn thing won't load at all... just generates a GPF and impolitely dumps me back to the desktop - mostly - occasionally the B.S.O.D.Bill

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>>So if you make any changes to the flight dynamics values >>using Notepad, you need to open the a/c in FS Ed. then save >>it again for them to take effect (be computed and written to >>the .air file). >>FSEdit is a flakey piece of bovine exhaust, as far as I can >tell. I've never been successful in using it (it keeps >crashing hard!), and lately the durn thing won't load at >all... just generates a GPF and impolitely dumps me back to >the desktop - mostly - occasionally the B.S.O.D. >>Bill I haven't had this problem of crashing. I have changed a couple of values to do with roll characteristics in FsEdit and then after saving, something happens to the aircrafts' flight performance . A 1930s heavy suddenly starts to accelerate like your Tocata!! :)A look at the old and new .AIR files using AirED reveals that 6 new "unknown " parameters have been added to the airfile after the save. Deleting these hasn't helped. I think I will go back to stamp collecting!!Barry

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BarryI saw this post some time ago, but I had no clue as to the identity of the aircraft in question, and since I don't post here unless I am reasonably sure I have something to contribute I let it go at that.However, after reading your response to another post on flight dynamics in the Flight Simulator forum that revealed the aircraft I.D. I decided to download it and have a go at fixing the roll dynamics.To cure the odd roll behavior, open the airfile with AirEd and scroll down to (Section) REC 1101 Primary Aerodynamics. Expand this section by clicking on it, and scroll down to the ------Roll----- entries. Change the following, Dihedral Effect *-2048= 215 Click on the number 215, in the box that opens change 215 to 50, then press the enter key to enter the new number.Save your changes and close AirEd.Open the CFG file with notepad or wordpad and locate the MOI section near the top of the document under [WEIGHT_AND_BALANCE], change the empty_weight_roll MOI as follows:;Moments of Inertiaempty_weight_roll_MOI=141677 (change to 78000)empty_weight_pitch_MOI=70636empty_weight_yaw_MOI=172848empty_weight_coupled_MOI=0.000000Again, save these changes and close notepad or wordpad. These changes cured the problem (at least on my computer), I hope you find they work for you as well.This should leave you with the typical "self leveling" FS2002 roll behavior and while I have no first hand experience with this aircraft in the real world, it is doubtful that it behaves this way even with 6 degrees of dihedral. Should you want to change this, and modify the yaw characteristics to improve rudder control and allow for better forward and side slips try the following-Open the airfile again, scroll down to (Section) REC 1101 Primary Aerodynamics, locate and change these entries:-----Roll-----Roll Moment Due To Aileron= -349 (change to -760)Roll Damping= -1500 (change to -3000)Roll Moment Due To Yaw Rate= -175 (change to -300)?Affects Smoothness of Roll= 0.00 (change to 0.054) I'm not sure about the effect of this entry. I used a default KingAir value because we can all do with more smoothness.-----Yaw--- + = Nose Left-----Yaw Moment - Sideslip (Weathervane Stab)= 90 (change to 300)Yaw Moment Roll Rate Adverse= -156 (change to -15)Yaw Moment Rudder= 90 (change to 225)Yaw Rudder Response= 15.000000 (change to 0 )Yaw Damping= -390 (change to -2000)Yaw Moment Aileron= 13000 (change to 0 )-----Side Forces-----Side Force-Sideslip Angle= -463 (change to -1172)Side Force-Rudder?= -232 (change to -187)Side Force-Roll Rate?=14 (change to 0 )Side Force-Yaw Rate(Skid)=368 (change to 709)In the CFG file:;Moments of Inertiaempty_weight_roll_MOI=78000empty_weight_pitch_MOI=75000empty_weight_yaw_MOI=75000empty_weight_coupled_MOI=0.000000After making these changes, I found the roll control to be much improved, and while I am never 100% happy with the FS 2002 yaw characteristics (or even 70% happy), I think the aircraft's adverse yaw behavior with these modifications is consistent with vintage aircraft that do not have differential or Frise type ailerons - you will need to "wiggle your toes" when you bank the wings. On your computer it may be different, or you may prefer different flight dynamics. None of these numbers are set in stone, and you should play around with them until you are satisfied, which is exactly what I did. Some of the values here are numbers I have found to work well and some are straight from the default Microsoft aircraft. A Microsoft Sidewinder Precision 2 joystick was used in testing these changes, I use it because it is, well, precise!Also, it is a good idea to start with FRESH copies of the original AIR and CFG files and DO NOT run FS2002 until you make the changes to these files after copying them to the problem aircraft's folder. As a precaution, I would delete the old files, and then copy the originals into place. And as stated above, I would also caution you against using FSEDIT for ANY purpose, it seems to have its own evil agenda. It has been my experience that changes made directly to the CFG file with wordpad are effective and safe, and with a good airfile editor like AirEd or FDE Editor from Abacus you then have all the tools necessary for flight dynamics editing.

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Thanks for this -- it has completely 'corrected" the airfile and the aircraft flies like I imagine it should!! :) Like you , I also don't know what the real aircraft would fly like - but , at least, in FS2002 , it is now flyable.With regard to your changes to the airfile, I believe there is quite an amount of info available about the various settings in the aircraft.cfg file , in the SDK and the FSedit helpfile -- but there is almost nothing available about the settings in the airfile. Now, I can appreciate that some of the "Gurus" might be unwilling to reveal their knowledge of these things -- but Father Bill has set us a good precedent in that he has promised to reveal to us his findings regarding the backlighting of Virtual cockpit gauges and not keep it to himself. What are your thoughts about starting a thread whereby we could "go through" the various and many lines of the airfile and get individuals (like yourself) to reveal what snippets of info they are sure about in relation to individual lines and collate this info into a website -- so that it is more readily available to all. Regards Barry

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Father Bill you MUST be Irish wit the "bovine exaust" label (of course you are right!) many of the tools that the "Gods of flightsim" provide us do baffle many of us!. Dan

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If you are serious in doing some flight model editing, be sure to download AFSD.

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BarrySounds like a great idea, an idea that in my opinion is long overdue, and if any individuals who are truly knowledgeable regarding this subject would care to participate, then I am certainly eager to learn and contribute what I can. A thread in this forum or even a dedicated website would address what I consider to be the most underdeveloped aspect of flight simulator - the way the aircraft behave in flight and on the ground. We have hundreds of beautiful visual models for aircraft and scenery, a dozen utilities that control every thing from the weather to the behavior of ATC and the AI aircraft, and all these wonderful features are wrapped around a dismal flight model. There are a few exceptions to this, some of the payware aircraft are quite close to reality as well as a some of the freeware offerings, but overall, and especially with regard to the default Microsoft aircraft, the flight characteristics are closer to those of a video game rather than a true flight simulator. Some virtual aircraft flight behavior, especially that of the defaults (Lear 45 for one!), would make any veteran test pilot hang up his or her goggles and quit if the flight were for real and they lived through it. I believe I can speak with some authority here, I am a private pilot with 15 years experience and hundeds of flight hours in general aviation aircraft, I have been employed by a major airline for the past 12 years as a crew scheduler, and I have seen airline captains (good friends who gave FS a try after much coercion from me) with thousands of flight hours shake their heads and offer what I will only describe here as "unkind remarks" after trying to hand fly the default jetliners (We must all bow our heads and give thanks for the autopilot). My husband is also a pilot with instrument, commercial, and mechanics ratings and he feels the same way about the flight dynamics. He also feels that I spend far too much time with this hobby, but that's another subject! And I find that most of my misspent time is involved in delving into the mysteries of the airfiles in a feeble attempt to unlock their secrets and achieve a more realistic flight simulation experience. I have searched for information on this subject and read anything and everything I could find, from Tom Goodrick to Rabbijah Guder, but I have the distinct impression that true experts on airfiles and virtual flight models are either employed by Microsoft and are bound by a strict non-disclosure agreement, or that any successful "reverse engineering" has been done by people who for one reason or another consider this information to be proprietary and are keeping it to themselves. William Roth, the creator of the very fine airfile editing utility AirEd, (who has earned my everlasting gratitude as AirEd has helped me to solve problems with low speed coefficient of lift and ground effect when no other airfile or hex editor could even reveal that these parameters existed much less modify them) seems to be one of the most knowledgeable people around when it comes to the construction and contents of the airfile itself, but it would seem that it is up to the individual users of his software to investigate and discover for themselves what the possibilities of the flight simulator program are where realism is concerned. That's part of the fun I guess! I am of the opinion that secrecy in any form diminishes us all, and while I acknowledge the commercial advantage that can be gained by a closed mouth, and also that there may be copyright or other legal issues with Microsoft that cause people to be discreet about this subject, when all is said and done this is a HOBBY not a national security issue. Also, I suspect the majority of flight simulator users are partly or wholly satisfied with the flight models, unless something really obnoxious and unmanageable is occuring, and this may limit the interest or participation aroused by this topic. It is possible that we are in a VERY small minority, a sort of "lunatic fringe", but I've been wrong many times before. However, I agree with you that Fr. Bill has set a fine precedent regarding the VC gauge lighting, and when time and my other obligations permit me to do so, I will follow his example by rendering aid when I can, and revealing anything and everything I know or have discovered about computer aircraft flight dynamics, but I have to admit - after 20 months of effort - I still don't know very darn much!

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Just to present an alternate point of view-I have had pretty good luck with FSedit so far. I used it for 3 new planes and also numerous downloaded planes just to tweak the performance a little.My goal has been to make the plane flyable within the FS environment, that is, it should not pitch all over the place when you touch the stick, you should be able to trim it, speeds and rate of climb should be reasonably close, and you should be able to flare and land without losing control. To do this I will take the cfg and air files from a similar FS plane that seems right to me, and then just modify the cfg file with FSedit (usually a lot). Now, this is heresy but I avoid messing around with wing areas, locations, cg, etc. I personally don't care how bogus the numbers are as long as the plane can be flown. If you make an air file with all the right numbers and then most people can't fly the plane and they dump it after downloading it, then the air file isn't worth much. For example, if you want a plane with stable handling and a heavy feel, use the 182 file and leave most of the numbers alone.You do have to change things like contact points. You also need Notepad to change some things like eyepoint and to add effects.The only problem I have had was from changing the reference point or cg location, and that caused all other locations to be recalculated. And like most of you say, back up the files first.Anyway, I certainly appreciate the efforts and knowledge of the experts, but if you are not at that level you have to work with what you have.John Woodward

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Hi Donna,Please visit http://www.avhistory.org/ . Click on the Message Boards menu item, then the air file submenu item.Also attached is the latest aired.ini I received from Ron. Just rename it aired.ini.

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To W. SieffertMany thanks for the link, I have visited the avhistory website several times but never noticed the airfile message board! Thanks also for the latest AirEd ini file, I can see the new information it contains will keep me busy for a long time.

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