DF

The Douglas DF was a transport aircraft developed by the Douglas Aircraft Company in the early 1940s as a successor to the DC‑3. It featured a low‑wing monoplane design, pressurised cabin, and twin Pratt & Whitney R‑2800 radial engines, giving a top speed of 310 mph, a range of about 2,200 nautical miles, and service ceiling near 20,000 feet. The DF first flew on 12 March 1943 from Santa Monica and entered limited United States Army Air Forces service in 1945. Only 162 units were built before production shifted to the DC‑6, but the type earned a reputation for ruggedness, ease of maintenance, and forgiving handling.

Commercial operators such as Pan American and BOAC used the DF on early trans‑Atlantic routes, proving the practicality of pressurised passenger service. The aircraft introduced structural advances, including a semi‑monocoque fuselage and retractable tricycle landing gear, which influenced later Douglas designs and set post‑war airliner standards. Although its production run was short, the DF represents a pivotal step in the evolution from prop‑driven transports to the jet age, and surviving examples in museums illustrate its historical importance.