R 42

The Junker R 42 was a single‑engine, low‑wing transport prototype developed in the early 1930s by Junkers Motorenbau und Junkers Flugzeugwerk. Conceived as a modern replacement for the aging Junkers G 24 series, the R 42 combined all‑metal construction with a streamlined fuselage and a retractable undercarriage, features that were still rare in German civil aircraft of the period. Powered by a 750 hp Jumo 205 diesel engine, the aircraft could carry up to twelve passengers or a mixed load of freight, while maintaining a cruising speed of 260 km/h and a range of roughly 1 500 km. Only two prototypes were built before the program was cancelled in 1935, as the Luftwaffe’s growing demand for military trainers and bombers shifted resources away from civilian projects. Despite its limited production, the R 42 demonstrated the aerodynamic efficiency of Junker’s cantilever wing design and validated the use of diesel powerplants in commercial aviation. Its structural concepts later influenced the successful Junkers Ju 52 transport, cementing the R 42’s role as an important, if overlooked, stepping stone in interwar aircraft development. Its all‑metal stressed‑skin construction set a standard for later Junkers transports, reinforcing Germany’s reputation for rugged, high‑performance aircraft before World II.