The duo were credited with six confirmed aerial victories together, beginning with a double victory over SPADs on 17 July 1918 over Courton Wood. The aircrew of Hengl and Baur were shot down behind British lines during the Third Battle of the Aisne; however, they were rescued from captivity by troopers from Württemberg. The pair would score another four victories in October 1918, with Hengl scoring a seventh while crewing for another pilot.