Complex sentence: He joined the U.S. Army in 1961 and served in the 82nd Airborne Division as a paratrooper to conquer his fear of heights, and survived a training jump in which neither of his two parachutes opened.
Split into simpler sentences: He joined the United States Army in 1961 and served in the 82nd Airborne Division as a paratrooper to conquer his fear of heights. He survived a training jump in which neither of his two parachutes opened.