Originally Posted by
Starman
I believe UA allocates award and upgrade seats with "married segment" availability, just as it does for revenue seats. So at times a given bucket will be available for x-y-z, but not x-y and/or y-z. For revenue tickets, it's a technique to maximize income; but it's unclear to me why they do it with award or upgrade seats.
Thanks for the suggestion, but I think that there must be something else in play here too - I booked the TUS-DEN-DCA flights and the TUS-DEN cleared immediately but the DEN-DCA flight didn't clear, despite it being NF5 as a "married segment".