ユーゴスラビア侵攻
The majority of the SIM-X aircraft were destroyed during the 1941 Invasion of Yugoslavia by the Germans and Italians. The German forces captured three aircraft (one in Zemun and two in Lazarevac). The air forces of the Croatian Independent State used one SIM-X until 1943 when it was destroyed by the Srem partisans in emergency landing.