Though given to sarcastic wisecracks and a stern demeanor with military doctrine. But behind those demeanor Birgit was a kind and good-natured individual, as he provides Seabook with support and encouragement when the young civilian is pressed into duty as a substitute pilot.
Even though Birgit was an Ensign, he was still a skilled mobile suit pilot, able to hold his own against the more advanced mobile suits deployed by the Crossbone Vanguard, even shooting down a few of them with his outdated RGM-109 Heavygun. He also seems to know a lot about F91 Gundam F91, as he immediately recognized Reese Arno's Ayatori that shaped like F91 Biocomputer panel grids.
In U.C 0123 Birgit pilots a RGM-109 Heavygun while helping Seabook, Annamarie Bourget, and Cecily Fairchild/Berah Ronah defend Frontier I from the Crossbone Vanguard's mobile suits. While Seabook piloted the F91 Gundam F91, Birgit was put in charge of making sure the press ganged civilian pilot knew the lay of the land, as well as tactics and actions on how to deal with enemy mobile suits, serving as a stand-in tutor despite his own limited experience.