I think you are thinking about this way too much. The mean profit per flight is about $500. This number tells you nothing about whether a particular half empty

I think you are thinking about this way too much. The mean profit per flight is about $500. This number tells you nothing about whether a particular half empty flight is profitable or not. Literally every flight except one could be empty and you could still end up at a mean value of $500 if that one remaining flight is profitable enough.