LaRCsim maintains all it's variables internally. I had been copying all of

LaRCsim maintains all it's variables internally.  I had been copying all of
them back and forth to the FG struture everytime I updated the flight model.
However, I have realized that this is not necessary.  I just need to copy
the control positions and environmental parameters into the LaRCsim structure
before updating the FDM, then copy every thing back out into the publick FGFS
structure afterwords.  This seems to solve (or at least help) a westward
drift problem some poeple had been observing.