It is strange how US pulled out of even a once-daily operation that dated back to 2000-01 with HP since PHX is HQ and a major hub, although it would mean using mainline equipment and not Republic or Air Wisconsin as for PHL and CLT.

It is conceivable that AC on the 28th has some sort of Nascar fan affinity group aboard, same reason as flights ex IND or DAB after a race are otherwise jammed out of cities which would have no such demand if not for the event.