Original sentence: He remained active in retirement, until he developed leukemia and died on November 2, 1997.His autobiography "Herman the German: Just Lucky I Guess" chronicles his life.The Gerhard Neumann Museum in Niederalteich, Bavaria, honors his contributions to aviation
Edited sentence: He remained active in retirement, until he developed leukemia and passed away on November 2, 1997.His autobiography "Herman the German: Just Lucky I Guess"  chronicles his life.The Gerhard Neumann Museum  in Niederalteich, Bavaria, honors his contributions to aviation