've modified the C180j's waterrudders.obj file in Blender 2.49, adding a bone to each armature (there is one for each rudder), then parented the original bone to the new bone. I've assigned the sim/flightmodel2/controls/water_rudder_deploy_ratio dataref to the new bones, which provides the retractable function. Now the problem : The water rudders are connected to the normal rudder with the sim/flightmodel/controls/rdruddef, and sim/flightmodel/controls/ldruddef datarefs. But when the rudders are retracted, those datrefs should be "disconnected". Is there a way to do this? Maybe in python ? thx Mike