Complex sentence: On 15 December 1944 Franzisket joined the Geschwaderstab of JG 27, and then was appointed "Kommodore" of JG 27 on 30 December 1944.
Split into simpler sentences: On 15 December 1944 Franzisket joined the Geschwaderstab of JG 27. He was appointed "Kommodore" of JG 27 on 30 December 1944.