Douglas B-23 Dragon (1939-1940): The Douglas B-23 Dragon, a twin-engine medium bomber, was a proposed improvement on the B-18A Bolo. The B-23 was a direct descendant of the DC-3, through the development of the B-18 and B-18A, and actually used some parts that were interchangeable with the DC-3. The B-23 was the first U.S. bomber to feature a tail gunner. Built in 1939 and 1940, B-23s were used for coastal patrol on the Pacific Coast during the early months of World War II. Later several were modified by the Army Air Force to UC-67 Utility Transports by removal of the bomb bays, nose and tail armament and the installation of passenger seats. In 1941, the B-23 was caught in the changeover to four-engine bomber philosophy and it was not any reflection on the quality of the airplane itself that more were not built. The Army Air Force declared most Dragons surplus after World War II. After 1945, the B-23’s high performance and dependability made them attractive as executive transports and led to their description as one of the most deluxe, high-speed, short-field, long-range executive transport aircraft of the post-war period.