First delivered to American Airlines as NC25629 "Flagship Kingsport" in July 1940, it served until 1949. It then briefly flew for Capitol Airways Inc. before passing to Ozark Air Lines Inc. who in 1957 re-registered it N137D. Retired by Ozark in 1967 it then passed through the hands of a number of corporate owners, including Air Exec (short for Air Executive Co.). This Ontario, CA based company, founded by James Webb and Russell Meek, was operational in the early 1970s. The aircraft was officially re-registered N29MA in December 1979, but that registration was never applied. It remained stored at Chino as N137D, which was still visible on the left-hand side of the fuselage at the time of this photo.