Originally Posted by
Blumie
I haven't looked into this flight, but I can tell you quite definitely that AA does this all the time. Generally speaking on a 3-class flight, a J seat is much more likely to sell than an F seat, so AA will oversell J so long as there are sufficient F seats to roll passengers forward. It's actually quite a smart move. And while it would be better if their system could, for example, show F1 J1 when in fact there's only a single F seat available, it apparently can't, so sometimes a flight will show F0 J1 when the only available seat is an F seat. (Actually, that's not a great example because I've never seen it happen with only one seat, but I have seen examples of a flight showing something like F2 J2 when the seat map shows four unassigned seats in F and no unassigned seats in J. This is a perfect example of the seatmap showing valuable, if not definitive, information.)
I don't think it's a matter that they *can't* show F1 J1 when there is one seat open in F and none in J. In fact, up until about a year or so, that's exactly how they did it. They also cross-list availability for farecodes within a cabin routinely (e.g., Y3 B2 would generally mean that only a total of three seats can be sold, not five). The new process is referred to as "cabin borrowing" and as you rightly describe it is the transfer of inventory from a higher cabin to a lower one when limited seats are available in the lower cabin. The reason I have heard it is done this way is to prevent triggering Sabre to designate the flight as overbooked. I imagine there may be other reasons that come into play too, such as more efficient inventory management (but just speculating).
The bottom line for elites waiting for upgrades is that it is good news since it can restrict sales in the higher cabin preserving seats for upgrades. When I see a flight has gone to F0 with seats open in F a few days before the flight, I am usually confident that my upgrade will clear. The downside in that scenario though, is that upgrades typically won't clear early - not usually until the window four to five hours before the flight (before it is handed over to the airport). At this time the inventory is redistributed so that upgrade inventory can open up (when a flight is F0, typically it can't have positive inventory in X).