He was born on May 27 , 1907 in Knoxville , Iowa .
William C. Mentzer ( May 27 , 1907 -- December 23 , 1971 ) was an aeronautical engineer noted for his contributions to the airline industry , dealing particularly with aircraft maintenance and economics .
William C. Mentzer was born on May 27 , 1907 in Knoxville , Iowa .
William C. Mentzer ( May 27 , 1907 -- December 23 , 1971 ) was an aeronautical engineer noted for his contributions to the airline industry , dealing particularly with aircraft maintenance and economics .