The O-47 was developed as a replacement for the
Thomas-Morse O-19 and
Douglas O-38 observation biplanes. It was larger and heavier than most preceding observation aircraft and its crew of three sat in tandem under the long canopy. Windows in the deep belly overcame the obstacle that the wings presented to downward observation and
photography. The design for the XO-47 prototype originated in 1934 with
General Aviation Manufacturing, a subsidiary of North American Aviation, as the GA-15. The Air Corps ordered 174 O-47s in 1937 to 1938, 93 of which were assigned to
National Guard units. In 1938, the Army ordered 74 O-47Bs with a redesigned engine cowling for better cooling, an uprated engine, and improved radio equipment. ==Operational history==