Complex sentence: Semen Zhavoronkov (1899-1967) was Soviet commander of a Naval Air Force During the Great Patriotic War (1941-1945), headed operations of the units under his command at sea and in coastal areas.
Split into simpler sentences: Semen Zhavoronkov (1899-1967) was a commander in the Naval Air Force. During World war II or the Great Patriotic War (1941-1945), Zhavoronkov headed units under his command at sea and in coastal areas.