Complex sentence: After World War I, Etrich moved to Trautenau, now Trutnov, in the newly founded Czechoslovakia, and built the "Sport-Taube", a closed-cockpit monoplane in the same factory where he built textile machinery.
Split into simpler sentences: After World War I, Etrich moved to Trautenau, now Trutnov, in the newly founded Czechoslovakia. He built the "Sport-Taube", a closed-cockpit monoplane, in the same factory where he built textile machinery.