R5O-4 Lodestar

The Lockheed R5O-4 Lodestar was a twin‑engine transport aircraft developed in the late 1930s as an evolution of the Model 14 Super Huddock. First flown in 1938, the R5O series entered service with the United States Army Air Corps, where the -4 variant was designated for light cargo and personnel ferry duties. Powered by two Pratt & Whitney R-1830‑94 radial engines delivering 1,200 horsepower each, the aircraft could cruise at 210 mph and carry up to 18 passengers or 2,500 pounds of freight. Its all‑metal, semi‑monocoque fuselage incorporated a spacious cabin, reinforced flooring, and large side doors that facilitated rapid loading. The high‑wing configuration gave excellent ground clearance and visibility, while the retractable split‑type landing gear reduced drag. The R5O‑4 played a critical role in pre‑World War II logistics, demonstrating the reliability of twin‑engine transports for medium‑range operations. Though quickly superseded by the larger C‑60 Constellation, the Lodestar proved a successful bridge between early single‑engine mail planes and the four‑engine airliners that dominated post‑war air travel, marking a pivotal step in Lockheed’s evolution toward modern commercial aviation. Its legacy endures in modern twin‑engine designs that trace their lineage to the Lodestar's engineering principles.