I’ve been thinking about DC power distribution in general.  Can someone explain the plan for Eagle to me?  In aircraft, at least in the one I am familiar with, they do not use the chassis as a return.  All DC power is treated the same way as AC power and distributed from a common point as a twisted pair to minimize common mode noise.  Great care is taken to eliminate ground loops by insuring that the ground returns are back through the twisted pair to the source and not through a sneak path to the frame.

 I agree. This is the way it was in the missile business when I worked on Tomahawk, Standard Missile and Talos from the 50s thru 1988.