Original sentence: Smith (1906 - 1976) was one of the most prolific and successful aircraft designers of the 20th century.Some of his famous designs included the A-26 Invader for Douglas, (under the direction of Ed Heinemann) the Aero Commander, for a company that he helped to start, and the Aerostar line, under his own name
Edited sentence: He went on to design small business jet aircraft for Aero Commander, a company that he helped to start, and the Aerostar line, under his own name.He worked for the Douglas Aircraft Company and Rockwell Standard Corporation and in his 40 years his designs included the A-26 Invader (under the direction of Ed Heinemann).Smith (1906 - 1976) was an American aircraft designer