SN have a great code-sharing agrrement with AA just like SR
They code-share on BRU-NYC ( twice daily )
-BOS ( one daily )
-ORD ( twice daily )
-IAD ( one daily )
-DFW ( one daily )
But when SN will fly to the hub of Miami like SR if SN go to Dallas it's time to go to Miami !
Is somebody have information about that?