Entered service with Eastern Air Lines in October 1937 as NC18121 (DC-3-201). Converted to a C-49G and to the USAAF from June 1942 to June 1944 as 42-56640. Converted to a DC-3A and back to Eastern as NC18121. to Trans Texas in December 1953 as N18121. To N136PB in March 1974. To private owners as N18121 from September 1993 onwards.