We’ve previously noted a small US Airways buildup to destinations in the western U.S.: US Airways began flights to Salt Lake City (SLC) and is resuming its summer-seasonal flights to Sacramento (SMF) earlier than previously was the case this year.

Recent fuel price increases show just you fragile such service is. Flights to both cities will now operate five days a week (not on Mondays and Tuesdays) instead of daily. This is the fifth year for summer-seasonal flights to Sacramento and its the first time service has been less than daily.

As for Salt Lake City, recall that after US Airways announced its service, Delta Air Lines responded by adding a CLT-SLC flight of its own. So it’s really not a good sign for the US Airways flight — which was suppose to be daily and year-round — that it will be down to five days a week come May, two months after it began.