Noltenius planned to follow his father into medicine but he joined an artillery regiment when the war began. He transferred to the German Air Force by the end of 1917 and scored his first victory over a Sopwith Dolphin in August 1918. On 15 September 1918, his Fokker D.VII was shot down by a Sopwith Camel piloted by American ace George Vaughn. Noltenius survived the incident to become one of the last German pilots to receive the Knight's Cross with Swords of the Order of the House of Hohenzollern.