US secretary of state Antony Blinken was reportedly stranded at a global elite conference by a malfunctioning aircraft from Boeing, his former corporate client.

On his return from the World Economic Forum in Davos, Switzerland, on Wednesday — where Blinken spent several days mingling with the global business elite — he boarded a Boeing 737 in Zurich, according to Bloomberg. But a “critical” issue with the aircraft instead grounded the secretary of state in Switzerland, and he was reportedly forced to fly home on a smaller jet.

The reported failure of the plane’s oxygen system is the third high-profile failure of a Boeing aircraft in the last two weeks, after a door plug blew out of an airliner over Portland, Oregon, on January 5 and then a Boeing 737-800 plane in Japan aborted a flight on January 13 after crewmembers found a crack in the cockpit window. Airlines have since reported finding loose bolts on other Boeing 737 MAX planes.