Douglas O-38F, Single-engine Two-seat Observation Biplane, U.S.A.

The DOUGLAS O-2B 25-351 Page of the Davis-Monthan Airfield Register Website

Drawing - Paul Matt - Douglas O-38 – RC Sport Flyer Store

Douglas O-2H

Historic DOUGLAS O-38F OBSERVATION Photo 8x10 (#601S)

United States Army Air Corps - Wikipedia

Historic DOUGLAS O-38F OBSERVATION Photo 8x10 (#600S)

Oz : Douglas O-38 plan - free download

United States Army Air Corps - Wikipedia

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USA: Warplanes of the Second World War preserved: Fighters, Bombers and Patrol Aircraft

Aside from the Imperial Japanese Navy, did anyone else in World War 2 develop (or attempt to) a seaplane fighter? - Quora

Drawing - Paul Matt - Douglas O-38 – RC Sport Flyer Store

Douglas O-2H

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Are there any aircraft that were not used in WWII but could have been useful if they were available? - Quora