In California, airlines move to smaller airports, vacation routes Tim Jue FacebookTwitterEmail Carriers at SFO have had to adapt to the massive changes in pandemic travel.Justin Sullivan/Getty Images Eric Yen of Millbrae is the kind of frequent flier the airlines need to pay the bills. He’s a high-yielding, high-value passenger the carriers fight to keep. When Yen needs to get somewhere for work, his presence is non-negotiable — he has to be there. Then the pandemic hit. Mass gatherings were out, and the exhibition industry he makes a living off of pulled the plug on in-person events. In 2019, Yen logged upwards of 90,000 miles out of San Francisco International Airport flying around the U.S. and abroad attending trade fairs.