(Moderator, is this the right thread for this question?)

The age old question: how far in advance will United release C seats for purchase using fare+miles+copay?

In the past, have had good luck purchasing tix several months in advance (often the max 11 month timeframe) and finding award upgrades available at the time of tix purchase. For long haul flights this is crucial for me; if I can't get the seat guaranteed, I won't purchase the ticket.

I know it might be equipment dependent, route dependent, etc etc. So, anyone have any data, or informed opinion, of the optimal lead time to try to purchase tix and upgrade/copay simultaneously? I'm looking at routes between IAD and: KWI, DXB, NRT, HKG, SIN, EZE, BKK

I'm looking at 2011 -- so I wonder if the merger is keeping most seats on many routes locked up for now???? Thanks for any thoughts!