Ishikawajima R-3

The Ishikawajima R‑3 was a single‑engine, low‑wing monoplane produced by Ishikawajima Heavy Industries (today IHI Corporation) in the early 1930s. Conceived as a versatile trainer and light transport, the R‑3 made its maiden flight in March 1932 and entered limited service with both the Imperial Japanese Army Air Service and several civil aviation schools. The aircraft featured an all‑metal stressed‑skin structure, a 450 hp Kawasaki Ha‑9 inline engine, a two‑seat enclosed cockpit with dual controls, and a fixed, split‑type landing gear that could be fitted with floats for maritime operations. Its wing employed tapered, cantilevered panels with a modest dihedral, giving the R‑3 stable handling at low speeds and making it ideal for pilot instruction. Though only 78 airframes were built, the R‑3 demonstrated the practical benefits of metal construction over the wood‑and‑fabric biplanes that dominated Japanese training fleets at the time. The design also served as a testbed for aerodynamic refinements later incorporated into the more famous Ki‑47 fighter‑reconnaissance aircraft. As such, the Ishikawajima R‑3 holds a modest but important place in Japan’s pre‑war aviation development, marking IHI’s transition from shipbuilding to aircraft engineering.