Nakajima Ki-4

This machine was the last biplane reconnaissance aircraft of the Japanese Imperial Army. It was initially produced by Nakajima in response to a 1931 specification for a reconnaissance aircraft that could also be used in the light ground support role. The first Ki-4s began equipping Japanese air units in 1933 and were an active part of Japanese reconnaissance efforts for a number of years thereafter. The Ki-4s saw substantial service in the Sino-Japanese, which that they joined in 1938. They also functioned as light ground attack aircraft in the support of advancing Japanese ground troops. However, these elderly biplane machines were vulnerable to even the oldest and slowest moving enemy fighters. By the time of the entry of Japan into World War II, the Ki-4s were hopelessly obsolete. Those that had not been lost in service or scraped served briefly as elementary trainers or target tugs. All of the Ki-4s were gone by 1943.