Does UA do any schedule mapping 4 days out?
From the fact that you can only search for a tail number 3 days out you *might* think that they don't assign one until then but we know this to be false.
Is there some operational handoff at that point? Or do they redo the schedule at that point to account for unanticipated maintenance?
Or are these processes continuous and occur as far out as necessary when a frame needs to be taken out of service for unscheduled maintenance?