Going through the several Navion POHs, the L-17 guidance, and one W&B spreadsheet posted I'm not getting a solid idea of the unusable fuel in our planes. The L-17 page says zero on unusable fuel while the posted W&B spreadsheet says two gallons per tank.........I'll guess that is the two main tanks.
So is there unusable fuel in the two main tanks? My understanding is that the Aux tank in the baggage compartment drains completely, I've not seen anything about the Mk1 Brittain tip tanks but from experience it seems that "dry tanks" leaves about a gallon in each tip tank.
Does anyone have anything solid on this?