Complex sentence: Robert A. "Bob" Hoover (born 1922) is a former air show pilot and United States Air Force test pilot, known for his wide-brimmed straw hat and wide smile.
Split into simpler sentences: Robert A. "Bob" Hoover (born 1922) is a former air show pilot and United States Air Force test pilot. His personal trademark is a wide-brimmed straw hat and wide smile.