Originally Posted by
LarryJ
It's not up to UA. CBP decides when they will process flights at C and when they'll have to go to B.
Sort of? CBP decides when they will staff the C FIS, but even when staffed and open, UA lacks sufficient sterile international arrival gates in C during peak hours such that some flights have to go to B. UA should prefer that all international arrivals park at C when C is open, but of course when C is closed (such as early mornings), every flight has to go to B.