O-2

The Douglas O‑2 was a two‑seat biplane built for the United States Army Air Service in the mid‑1920s, emerging as a refined version of the earlier O‑1 “Curtiss Falcon”. First flown in 1925, the O‑2 entered service in 1926 and remained active through the early 1930s, performing artillery spotting, battlefield reconnaissance, and training duties. Its airframe combined a welded steel‑tube fuselage with wooden wing ribs and fabric covering, yielding a sturdy yet relatively lightweight structure. Power came from a 420‑horsepower Liberty L‑12 V‑12 engine driving a two‑bladed propeller, giving the aircraft a top speed of roughly 115 mph, a service ceiling near 12 000 ft, and a range of about 300 miles. The cockpit arrangement placed the pilot and observer in open, side‑by‑side seats, allowing clear communication and excellent downward visibility, while removable photographic equipment could be installed for mapping missions.

The O‑2’s significance lies in its role as one of the first purpose‑built observation platforms, helping to codify aerial artillery‑adjustment techniques that later became standard in World War II. Its reliable performance and straightforward maintenance also made it a valuable trainer, influencing the design of subsequent Douglas observation types such as the O‑38 and O‑46, and cementing Douglas Aircraft’s reputation in military aviation during the interwar period.