The North American O-47 was a pre-war American observation fixed-wing monoplane aircraft used by the United States Army Air Corps. It had a low-wing configuration, retractable landing gear, and a three-blade propeller. 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. During World War II, it was deployed for a wide range of routine operational duties such as towing targets, coastal patrol, and anti-submarine patrol. This book describes in great detail the development history and service history of this overlooked aircraft. Many unpublished photographs, new colour profiles and scale plans complete the story.