 Complete the following phrase:  On 2 August 1943, JG 3 Udet began transferring to Western Front and flew in Defense of the Reich. The Gruppe arrived at Münster-Handorf Airfield the following day where they were placed under its new commander Hauptmann Walther Dahl. On 7 August, the unit for the first time practiced the Y-Control for fighters, a system used to control groups of fighters intercepting United States Army Air Forces USAAF bomber formations. Lemke claimed two USAAF Republic P-47 Thunderbolt fighters shot down on 17 August during the 