that's up to the union to decide but , just ask the ups pilot when they went on strike what they thought about the arrow crew that was trying to go there and fly their stuff, or the CAT guys.
as of right now if you flew PO freigth on a po route you would be a scab ( provided we found out)
know, what do you thnk? how would you feel about doing that? would you doit if your contract allows you not to do it?