Aviation of World War II
To replace the newly adopted Mitsubishi 2MR8 Type 92 army reconnaissance aircraft in 1933, the Technical Department of the Imperial Army Headquarters Kōkū Hombu signed a contract with Nakajima to develop a light aircraft capable of performing the functions of close reconnaissance and direct support of ground troops. At the same time, the requirement for maneuverability comparable to modern fighters was stipulated. Due to the fact that it was decided not to hold a traditional design competition, Kōkū Hombu sent his representative, military engineer Nario Ando, to the firm as project manager. The chief designer was the engineer of the company Nakajima Shigetoro Owada (Shigejiro Ohwada).
The original design was an all-metal polutoraplan with elliptical wings and a Nakajima "Kotobuki" radial engine. The fuselage of a monocoque design with a metal set and fabric covering, as a whole, repeated the proven design of the Type 91 fighter.
During the development process, many changes were made to the design. A new, more powerful Nakajima Ha-8 Type 94-1 "Hikari" nine-cylinder radial engine with a take-off power of 640 hp was installed.
The first three prototypes were completed in March, April and May 1934 respectively. The tests were carried out by Tai army pilots (captains) Saburo Amakasu and Yozo Fujita, along with Nakajima test pilot Kiyosho Shinomiya. During flight tests, it was determined that the fuselage should be enlarged, which was done on the fourth prototype.
The modified aircraft showed excellent maneuverability, good stability and excellent handling. It was adopted by the army in July 1934 under the designation "Army reconnaissance Type 94 model 1" or with the short name Ki-4, after which it was put into production at the Nakajima and Tachikawa factories, and a little later at the Manchurian company Manshu, where until February 1939, 333, 54 and 126 Ki-4 scouts were produced, respectively.
Structurally, the reconnaissance Ki-4 was a two-seat single-engine polutoraplan. with an all-metal monocoque fuselage. The power set of wings is mixed. Linen upholstery. The power plant is a Nakajima Ha-8 nine-cylinder radial engine Type 94-1 "Hikari" with a take-off power of 640 hp. and nominal 600 hp
Non-retractable landing gear with a tail spike. On the first production machines, the wheels were covered with fairings, which were later abandoned. The pilot and gunner-observer were located in separate cabins, each of which was equipped with a plexiglass visor. Above the cockpit in the upper wing there was a cutout that improved visibility.
Armament consisted of two synchronous fixed 7.7-mm Type 89 machine guns in the forward fuselage and two coaxial Type 89 machine guns in the rear cockpit. On machines of a later release, the shooter had a pair of Te-4 machine guns of the same caliber. In the process of serial production, bomb racks for six light anti-personnel bombs with a total weight of up to 50 kg appeared under the lower wing. The aircraft allowed dive bombing at an angle of up to 50°. Air brakes, however, were not provided.
Shortly after the start of production of the first version of the reconnaissance Type 94 model 1, an improved version of the Type 94 model 2 or "Type 94-Otsu" went into mass production, on which the previously used separate engine exhaust pipes were combined into two common wide manifolds along the sides of the fuselage . In addition, wheel fairings were removed from field airfields to facilitate the operation of the aircraft. Modification "Type 94-Otsu" was produced mainly at the Tachikawa Hikoki and Manshu Hikoki factories.
To accommodate the aircraft's ability to operate from rivers and lakes in China, the 6th prototype was fitted with a float landing gear with one central float and two supporting floats, borrowed from the E4N2 float reconnaissance aircraft. Another of the prototypes was installed on two main floats. Both options were tested at the Aviation Technical Research Institute as part of the naval Kasumigaura. But none of them was adopted due to the fact that the concept of its potential use was not clearly defined.
Nevertheless, the fleet became interested in the army scout to use it as a deck to replace the outdated C1M. This is how the modification Type 94 model 3 appeared - a deck version, the only difference from the Model 2 of which was inflatable bags placed on the sides of the fuselage to increase the buoyancy of the aircraft in the event of an emergency landing on water and the presence of a landing hook. However, the series of carrier-based vehicles of this type was limited to the production of six pieces, which were not used for long on board the Kaga aircraft carrier.
Based on the Ki-4, the Type 94-T civilian multipurpose aircraft with two seats in the rear cockpit was also produced.