"Air Age Debut: Introducing new features of speed, comfort and operating efficiency to air travelers is United Airlines' four-engined, five-mile-a-minute Mainliner 300 (Douglas DC-6), accommodating up to 52-56 passengers plus 6000 pounds of cargo. Airport scenes such as this emphasize the immensity of the new luxury airliners with their 117 ½ foot wing span and 100 ½ foot length." (United Air Lines Photograph)

Delivered to United Airlines as NX37503 in November 1946. To Mars Aviation on 23 June 1968 and then BMR Aviation in September that year. Registration cancelled on 14 June 1976 and then to an unknown owner in Oklahoma City, OK. Further registration changes noted in January 1977 to the same owner and then reported as scrapped. (United Airlines Photograph No. 308 - 1947)