A United Airlines flight bound for Japan had to return to the gate at San Francisco International Airport on Monday due to a mechanical issue with the plane. The incident marks at least the 10th of its kind involving the U.S. airline in the past two weeks. Flight UA35 was scheduled to depart for Osaka at 12:05 p.m. After taxiing on the runway for more than an hour, the plane — a Boeing 777-200ER — returned to the gate, and passengers and crew deplaned around 1:45 p.m. Belinda Pitco, a passenger onboard the flight, told the Chronicle that the pilot...