United Airlines this week mounted a counterattack against Delta Air Lines on its bread-and-butter Seattle-San Francisco air route.
United published a schedule beginning in April that will increase its flights between the two cities from nine to 11 daily. That new schedule eliminates smaller regional jets from that city pair and substitutes full-sized Airbus and Boeing jetliners for those planes.
Delta fired the first shot in that war last month when it announced it will begin flying six times daily between the two cities in late March. It will increase its flights to seven planes daily each way in June.
Delta partners will fly 76-seat Embraer regional jets on the route compared with United's bigger planes. The Embraer aircraft, however, will be equipped with a first-class section.
Two other airlines compete on that route, SeaTac-based Alaska Airlines, which flies the route seven times daily with Boeing 737s, and San Francisco's Virgin America, which has five roundtrips daily using single-aisle Airbus planes.
With the new additions from Delta and United, the four airlines will be flying 30 roundtrip flights between the two cities by next spring, nine more than now.
The addition of nine more flights seems sure to spark a full-fledged fare war on route perhaps spreading to other Bay Area routes from SeaTac.
Stay tuned as spring nears for introductory specials perhaps as low as $69 each way.