Complex sentence: So Dürr designed LZ 126, and using all the expertise accumulated over the years, the company finally achieved its best Zeppelin so far, which made its first flight on 27 August 1924.
Split into simpler sentences: So Dürr designed LZ 126, and using all the expertise accumulated over the years, the company finally achieved its best Zeppelin so far. It made its first flight on 27 August 1924.