Jernnard boarded the plane Wednesday evening wearing a white button-down shirt with an Air France logo over the pocket and a black jacket with four gold stripes on the epaulets, akin to one worn by pilots, police said.He also was carrying a bad fake of an Air France crew badge and a fake crew identification card, according to police and Air France spokesman Cedric Leurquin.Before he boarded the US Airways flight, Jernnard had a disagreement with airline personnel who could not accommodate his request to be upgraded to business class, police said.Police believe he sauntered into the cockpit while passengers were boarding the plane. The pilot’s door is usually open at that time, police said.A flight attendant conducting a routine head count entered the cockpit and saw the man sitting in the jump seat behind the captain’s seat. He identified himself as an Air France pilot.At least two pilots were doing pre-flight checks on the Airbus when the man entered the cockpit, Sullivan said.“He identified himself as a pilot and started to sit in the jump seat. But he immediately had a problem getting strapped in and it was obvious to the real pilots that he couldn’t be a pilot,” Sullivan told CNN. “He didn’t know what he was doing.”The flight crew told him he would have to fill out paperwork, but the man didn’t have credentials, police said. The captain then told him to leave the area, and the man became irate, police said.Unable to calm him down, the flight crew escorted him off the plane, police said.An airline agent tried to re-book him on another flight while U.S. Airways corporate security was notified, police said.When corporate security realized they had a possible crime on their hands, the man had left the terminal for his re-booked flight, police said.Corporate security contacted Philadelphia police, who found and arrested the man at his new terminal, Sullivan said.