I hope this doesn't turn into a mud sling because I just want to bring to light the reasons why it's important and positive for ALL of us in the flight simulation community to have alternatives like Flight Gear.First of all those of you who feel threatened by alternatives like Flight Gear (for whatever reason) should really calm down, no one is willing or going to ruin or take your Microsoft Flight Simulator away.But you must remember this is an ALTERNATIVE to MSFS that many of us, contributors to Flight Gear or not, find not only necessary but in many cases vital for the sake of competition.Remember also that a lot of people just aren't conformists, and when we are offered the option and FREEDOM to improve, change or create something, we more than welcome that!.Do you really think FS9 would be what it is today if alternatives like Sublogic's ATP, Flight Unlimited 3, ProPilot 99, Fly!/Fly2K/Fly2 and X-Plane wouldn't have existed?I tell you what...I've been using SRTM scenery in Flight Gear for some time now...in FS9 only recenly have those begin to appear.And I don't say this to start a discussion...I'm just saying it because it could be that Flight Gear is rising the bar...and that Microsoft could notice that and then improve their own. You see...sane competition IS good.In the end...it's us, the users, who benefit from it all.Why complain or start to belittle things just because we're not interested?Flight Gear is for those of us who:- enjoy flying- like to try new things- feel the current flight simulators are not enough- like to have the FREEDOM and CHOICE of improving our flight simulation experience (just like 3rd party authors in MSFS, but with more access to the main product, unlike MSFS)- enjoy the idea of giving back to the community the improvements and creations we make- prefer to invest our time and skills in building an open and free (as in freedom) system that we know one day will not just: a) deprecate our creations by making changes to their especifications and/or formats without telling anyone, :( force us one day to give up our creations or just stop us from creating them, c) limit us in how far we want to go when it comes to changing their system, and d) charge us for things that are never complete.I know that Microsoft has been really careful in keeping backwards compatibility with each version they release and that they have never showed intentions of "taking ownership" of everything released by the community...however...with Flight Gear I just KNOW that this will never happen...and I can always help in the development process and have access to the source code and to the main developers, so these risks I mentioned just don't exists. (And yes, to some of us those risks DO matter).So let's just enjoy what all the current Flight Simulators have to offer and be greatful to all of those who dedicate their time in making our virtual flying experience an enjoyable, realistic and FUN one, be it 3rd party addons for commercial simulators or developer of free ones like Flight Gear.thank you all :)-Enrique

Enrique,My apologies if I missed something, but I haven't seen anyone complaining about the existence of FlightGear. In fact, a simulation enthusiast would have to have two or three massive holes in their head to not want competition, whether it be open source or otherwise. It keeps the whole industry improving and on their toes. That's good for all of us. So, I don't see an issue, and haven't heard of any - and I am hoping I don't. :)

no apologies needed, I was a bit annoyed with a thread that developed a few messages below...that's all ;)btw...long time no see...will try to get my butt to the convention this year if time (and budget) permits; would be nice.cheers-Enrique

And I'll again add that, at least SO FAR, Microsoft hasn't even BEGUN to replicate the smooth instrument movements that X-Plane and Flightgear both have. To go even further, if MSFS ever does produce the kind of instrument movement that those two sims have, I'll probably never use another sim. Until then, there will always be room on my hard drive for programs like Flightgear.On a Flightgear related topic, I think it would be great to see someone (maybe Curt?) address how different flight sims produce a flight model (on this forum), and what considerations were taken when choosing the engine used in Flightgear.

>On a Flightgear related topic, I think it would be great to>see someone (maybe Curt?) address how different flight sims>produce a flight model (on this forum), and what>considerations were taken when choosing the engine used in>Flightgear.Hey, I'm just a lowly computer science guy ... I leave all that hard physics and aeronautical engineering stuff to the really smart people. :-)I can say a couple brief things though.First, FlightGear supports multiple flight dynamics models. We have 3 major sets of code built in, plus the ability to interface to external (possibly proprietary flight dynamics models.) I'll refer henceforth to "flight dynamics model" as FDM.The first built in FDM is called JSBSim. It is developed primarily by two people, one who works as a contractor for NASA, and the other for Boeing. It is a traditional table based approach. Lest people misunderstand, JSBsim is based on a very carefully constructed physics model. The table lookups are there to tell the physics what forces and moments happen under different circumenstances, but it's still 99% physics.The second built in FDM is called YASim. It is a novel approach I haven't seen before. You input basic aircraft geometry and mass properties (kind of like you do for X-Plane.) But that's where the two approaches diverge. In YASim, you specify a cruise configuration, and an approach configuration, and it has a built in solver that mixes that, along with the mass/geometry information to produce a reasonably behaving model that works remarkably well given the little amount of data you have to feed into it. It's also lightning fast compared to X-Plane's FDM.Comparing X-Plane's FDM to YASim, X-Plane is good if you know the aircraft mass and geometry and want to have a ball park idea of how the aircraft might fly. If you know exactly how you want the aircraft to fly, then you have to start working some x-plane voodoo to make that happen. YASim is good if you have similar basic aircraft data that you'd feed X-Plane, but also have an idea of what performance numbers you are shooting for. YASim's solver will nail them dead on.Finally the 3rd major built in FDM is called UIUCsim (notice the naming pattern?) :-) It's built by an aero engineering group at University of Illinois, Urbana Champaign. Their original goal was to do icing related research which they still continue doing I believe. Said nicely, their research advanced much more quickly when they used FlightGear as a framework, than with the stuff they were using before.All of these FDM's allow aircraft designers to specify a particular aircraft configuration in an ascii text file. No reverse engineering binary files here.Combine our flexible FDM configuration, with support for a variety of 3d file formats, a very powerful and flexible object animation system, and the ability to do fully interactive 3d cockpits and the result (with some effort) is the ability to create aircraft with just about any level of fidelity you like ... even to the point of FAA level 3 FTD certification which is a small teaser for some future thread. :-)Regards,Curt.

For anyone interested in more info on JSBSim, UIUCSim, etc, see the following page at the FGFS site:http://www.flightgear.org/links.htmlTom(P.S. Where do I upload a copy of 0.9.4, etc? NOTE: 'fgsetup-0.9.4.exe' is an 83.6Mb file. Even with 256K DSL it is still going to take me over 2 hours to download it. Also, remember, this is all under the GPL.)

Tom,You can upload here:http://library.avsim.net/upload.php

>On a Flightgear related topic, I think it would be great to>see someone (maybe Curt?) address how different flight sims>produce a flight model (on this forum), and what>considerations were taken when choosing the engine used in>Flightgear.Greetings:Here's just a short note to point out that if you are interested in one of the ways flight modeling is done for FlightGear you can check out the JSBSim web site: www.jsbsim.org. I just began publishing a newsletter for JSBSim, and the link is there on the main page.Best regards,Jon BerndtCoordinator,JSBSim Projectwww.jsbsim.org