weliwarmer wrote in Thu Sep 13, 2018 8:42 pm:I don't (yet) understand how the SITL script runs as an external FDM enough to modify it. Time for more reading....
yeah, your SITL FDM that is controlling your craft is where you need to do this balloon lifting simulation part... we thought you were doing this simulation in FG with one of FG's available FDMs or possibly your own self-written one in XML and NASAL... it wasn't until you mentioned using an external FDM powered by your Ardupilot SITL that things clicked... FG is only showing you the visual results of your FDM's execution