JSBSim is an open source flight dynamics model used by FlightGear. The project web site is at www.jsbsim.org.I wanted to mention that we put out a quarterly newsletter of general interest with some technical content. You might want to have a look at the current (and previous) issues. Visit the JSBSim web site and click on the Newsletter link at left, or one of the other links at the top of the main page.Best wishes,Jon

I think the YASim also have some bugs .

YAsim is still work in progress.

I'm not really familiar with YASim, though I know that many people have expressed a high degree of satisfaction with it.My intent in this thread was to announce only that I have just released a new JSBSim newsletter. See www.jsbsim.org.Jon

But YASim can control a Heavy Metal Jet airplane fly in the solar , JSBSim can not do this , though it is have a new improved version .

>But YASim can control a Heavy Metal Jet airplane fly in the>solar , JSBSim can not do this , though it is have a new>improved version . ??I think you are mistaken.

YASim is just a flight sim-model system for 747 and other heavy metal jet aircrafts , isn`t it ??

>YASim is just a flight sim-model system for 747 and other>heavy metal jet aircrafts , isn`t it ??No. It's a generic flight dynamics model that uses geometry of vehicle and performance characteristics to approximate the response of a vehicle to control inputs. YASim models many aircraft at this time, including general aviation, fighter jet, and airliner types. I don't know how good the engine models are - I haven't used it.JonJSBSim Project Coordinatorwww.jsbsim.org

Er... , I just want know which one is better ?? , between YASim and JSBSim .

JSBSim is more mature.

Totally mature ??

>Totally mature ??I've seen simulators that have been used for thirty years that are not what I'd call "mature". I will say this: JSBSim has been used in years past for several serious projects. The list keeps growing today. It's up to you to decide if it's mature enough for your task.Jon S. Berndt