Doc was converted to a radar calibration aircraft in 1951 and based at Griffiss Air Force Base, New York. Squadron members at Griffiss named their B-29s after the characters in the movie Snow White and the Seven Dwarfs, and 44-69972 became Doc. In 1955, Doc was modified as a TB-29 and moved to Yuma County Airport in Arizona, where it was used as a target tug