In 1932, the Northrop Corporation had been formed as a partly owned subsidiary of Douglas and by 1937, the Northrop Model 8 became known as the Douglas 8A produced in the El Segundo Division of Douglas aircraft.
The 8A-5 was powered by a 1,200 hp Wright R-1820-87 engine and was the most powerful and best armed of the series, fitted with four wing mounted 0.30 in machine guns, two 0.50 in machine guns in pods below the wing and two rear-firing flexibly mounted 0.30 in guns, and could carry up to 1,800 lb of bombs.
Early in 1940, The Norwegian Government ordered 36 8A-5s which not had been delivered before Norway was invaded by the Germans. Completed between October 1940 and January 1941, the aircraft were delivered to a training centre in Canada that had been set up for the Norwegian Government-in-Exile, at Island Airport, Toronto, Ontario.
After the loss of two aircraft and a reassessment of the training needs now met by the use of other aircraft, the remaining total of 34 Model 8A-5Ps were sold to Peru, however 31 were repossessed by the Army Air Corps at the start of World War II. These aircraft, designated A-33, were used for training, target tug, and utility duties.
Francillon, René J. McDonnell Douglas Aircraft since 1920. London: Putnam, 1979. ISBN 0-370-00050-1.
Pelletier, Alain J. "Northrop's Connection: The unsung A-17 attack aircraft and its legacy, Part 1". Air Enthusiast No 75, May–June 1998, pp. 62–67. Stamford, Lincolnshire: Key Publishing. ISSN 0143-5490.
Pelletier, Alain J. "Northrop's Connection: The unsung A-17 attack aircraft and its legacy, Part 2". Air Enthusiast No 77, September–October 1998, pp. 2–15. Stamford, Lincolnshire: Key Publishing. ISSN 0143-5490.
Wagner, Ray. American Combat Planes of the 20th Century, Third Enlarged Edition. New York: Doubleday, 1982. ISBN 978-0-930083-17-5.