RD-1 Dolphin

The Douglas RD‑1 Dolphin was a single‑engine, all‑metal amphibious aircraft developed in the late 1930s to meet the U.S. Navy’s growing demand for versatile sea‑plane reconnaissance and transport. First flown on 12 June 1939, the Dolphin incorporated the latest advances of its era: a retractable high‑wing configuration, a 1,200‑hp Wright R‑1820 cyclonic engine, and a watertight hull built from duralumin that gave the aircraft a maximum speed of 210 mph on water and 235 mph in the air. The cockpit featured dual controls and the first fully faired “step” that reduced drag during take‑off from both runways and open seas. Production was limited to 68 airframes before the outbreak of World War II shifted Douglas’s priorities to larger patrol bombers. Nevertheless, the RD‑1 proved vital in early Atlantic patrols, providing reliable night‑time observation, short‑range cargo delivery, and medical evacuation for isolated island bases. Its innovative hull‑to‑wing attachment system influenced later designs such as the PBY‑5A Catalina, cementing the Dolphin’s place as a transitional bridge between wooden floatplanes and the all‑metal amphibians that dominated the 1940s. Today, a restored example flies in National Naval Aviation Museum, where it educates visitors about the evolution of amphibious warfare and engineering breakthroughs pioneered by Douglas in pre‑war years.