> The _only_ difference between now and what we had before is now the position > may be reported at a fixed location on the aircraft by JSBsim. > Before it was reported at the _current_ center of gravity which varies > according to load, fuel consumption, etc. I'm sorry to be so dense, but could > some explain what this is going to mess up?
Say that initially JSBSim and the 3D model both agreed on where the "center" was - for JSBSim we simply report the CG location. OK, so the 3D model is flying along nicely - even took off nicely (since the CG matches where the 3D model rotates about in this example). Now, let's say we have fuel burnoff on one wing tank but not the other, so we end up with a CG that is two feet to the left of the fuselage at around the quarter chord (if you could even fly that, but humour me). The 3D model stil thinks the center of rotation is at the initially specified CG point, right? Now, when the aircraft lands, the FDM knows about all the contact points and where the CG is currently, and say one main gear (right) touches down well before the other. When the aircraft touches down the right gear, visually the right gear would hover above the runway some distance, because it is rotating about the initial CG, yet the FDM is rotating about the left-displaced CG, which has also a different altitude than is visually being shown Jon _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
