So I'm playing 1.0.4 with FAR, and the firespitter airbrakes don't seem to generate any drag, or rather, no more drag when open than closed. The stock airbrakes work (but are huge and not incrementally openable). I noticed that I didn't seem to be slowing down any faster with the firespitter brakes open then closed, and the aero forces overlay (f12) shows no change in the drag force arrows as I open them either either. I performed the test at high speed to try and ensure that if the arrow was changing, I would see it. I checked on two different installs (windows and linux) and it's the same thing. - - - Updated - - - Dug into the code a little bit, think I found the issue (though not sure how it's best fixed). FSairBrake seems to operate by changing the minimum_drag/maximum_drag values of the part. FAR appears to set these parameters to zero for all parts during initialization because it wants to do the aerodynamics. Now, to my knowledge FAR should be generating voxelized surfaces for the airbrakes (which should then in turn produce drag), but I'm guessing that's not happening. Whether that's FAR's fault or firespitter's fault I don't know. I'll see if I can get ferram4 on IRC and ask him about it.