During the invasion of Yugoslavia by the Axis the SIM-XI fell into the hands of the Germans and they handed it over to the puppet state, the Independent State of Croatia (ISC) where they designated it under the code 7351. The Croats used it until 19 December 1943, for glider towing, until partisans destroyed it between the villages of Progar and Boljevci when a Croatian pilot landed in order to reattach and lift the hook that had fallen off.