Usually, the only WB slots for DCA that show up in a class drop would be DCA 756… Usually WB slots will always be some form of SFO, EWR. If you are really wanting DCA or ORD and your best shot will be the 737/A320 and then bid up into the base/equipment/seat you desire on the future vacancy bids.. You second best shot will be the 756 and same deal. It will take a little bit longer but you should be able to get to EWR on the 756 equipment fairly quickly and over time you’ll get to DCA/ORD. Forget about it in the 777, you will be commuting to SFO for awhile, no ORD base. 787, similar thing, but you might get to EWR quicker vs the 777. But DCA or ORD on the 787 will likely take at least a year best scenario… DCA on the 777, longer…