Passengers heading to China aboard a recent United Airlines flight faced an unexpected travel headache after a pilot’s forgotten passport prompted their return to the United States.

Flight UA198 from Los Angeles to Shanghai was over the Pacific Ocean on Saturday afternoon when it made a U-turn and headed to San Francisco, tracking data showed.

United confirmed on Tuesday to AFP in an email that the plane, a Boeing 787 with 270 people onboard, made a stop in San Francisco “as the pilot did not have their passport onboard”.