A U.S. Air Force plane carrying Secretary of State Marco Rubio to Munich was forced to turn around over the Atlantic on Thursday night after a crack was discovered in the cockpit windshield, a U.S. official told Reuters. The plane was a C-32, a converted Boeing 757, the news agency said. Rubio was en route to the Munich Security Conference, where talks on the Russia-Ukraine war and potential negotiations are expected to take center stage. Approximately 90 minutes into the flight, a single crack developed on the windshield, prompting pilots to turn back at a low altitude, according to CBS News chief foreign affairs correspondent Margaret Brennan, who was aboard the plane. The aircraft “experienced a mechanical issue,” State Department spokesperson Tammy Bruce said. She added that Rubio “intends to continue his travel to Germany and the Middle East on a separate aircraft.” The plane landed safely back at Joint Base Andrews, Maryland, at around 10 p.m. ET.