Could that be somehow hard-coded into the model during the construction in 3DS or Blender? Honestly, I have no practical knoweldge about 3d modelling. I am drawing my conclusions from my fiddling with data.ini files in trying to add or fix turning front landing gear and shocks. There are models where no matter what ini dancing I did, the front gear would not turn properly along the correct axis and/or the shocks would not function correctly. That made me believe such movements are somehow hard-coded into the model during the construction in 3DS or Blender. So, my guess is, that unless these movements are planned for and provided for during the model construction, the ini file alone will not help. I would put my bet the same applies also for rotors rotation axis. Of course it would be best if one of our 3D experts could confirm or reject that and shed some more light on the topic.