 Complete the following phrase:  In East Prussia the Luftwaffe sent an 800-strong force under 4. Fliegerdivision. JG 54, operating the Fw 190 fighter versions along with SG 4 supported the German Fourth Army and enabled them to halt the Soviet attempt to crush the Courland pocket. On one day, 27 October, the Fw 190 fighter unit JG 54 claimed 57 aircraft shot down. SG 4 lost 17 Fw 190F ground attack machines. On 28 October, Erich Rudorffer claimed 11 victories, reaching a total of 209. Fw 190s of JG 54 claimed 600 victories between 14 September and 24 November, while the Soviet units reported a total loss of 779 aircraft. The crisis on the Eastern Front now required all available units to return to the theatre. The Battle of the Bulge in the Western theatre was still ongoing, but with the 