Aviation of World War II
Initially, it was assumed that the new aircraft would be a single-seat long-range escort fighter. However, in July 1942, the design team was disbanded, and the engineers from various companies that were part of it were recalled to perform more urgent tasks, and it was decided to retrain the new aircraft into a heavy multi-role fighter designed for operations at low and medium altitudes and at the same time capable of hitting heavily armored ground and surface targets. To speed up the work, several engineers were sent to the institute from the 1st Army Aviation Arsenal, also located in the city of Tachikawa.
Based on the new tasks, they decided to equip the aircraft with a large caliber gun for aviation (57 mm), around which the entire aircraft was built. The gun was housed in the ventral gondola.
February 22, 1943 the project of a new fighter was approved by Koku Hombu and received the designation Ki-93. At the plant of the 1st Aviation Arsenal, they began building two ordered prototypes for flight tests and one for static ones (according to verified data, 12 prototypes and prototypes were ordered). The new aircraft was a two-seat, twin-engine, cantilever, low-wing, all-metal structure with a closed common canopy cockpit and a tricycle wheeled landing gear using a tail wheel. The workplaces of the crew members and the sealed fuel tanks located in the fuselage were covered with steel plates 12 and 8 mm thick. In front, the pilot was protected by bulletproof glass 70 mm thick. It was supposed to use Mitsubishi Na-214 engines with an estimated power of 2700 hp as power plants.
During the manufacture of prototypes, it turned out that it would not be possible to provide the required mass. This was due to the greater than expected mass of equipment, as well as the complete lack of experience on the part of the developers in creating combat aircraft. In order to at least partially correct the situation, the ammunition load of the No-401 gun had to be reduced from 30 to 20 shots. Additional problems were delivered by engines that did not reach their design power on tactics.
As a result, the first prototype of the Ki-93-01 was assembled only in March 1945. On April 8, test pilot Moriya lifted the aircraft into the air from the Tachikawa airfield. The first 20-minute flight was for the Ki-93 and the last. When landing on viscous soil, due to too high a landing speed, the aircraft crashed, as a result of which the left half-wing, engine, propeller and main landing gear were damaged or completely destroyed.
The prototype was returned to the factory for repairs, which took four weeks. When the aircraft was almost ready for test flights, American aircraft raided the airfield and factories in the city of Tachikawa, as a result of which the aircraft was completely destroyed.
It is difficult to judge the performance of the Ki-93, only one report of a single flight has been preserved. It noted that the aircraft had good flight characteristics, and all on-board equipment worked flawlessly.
The second prototype of the Ki-9302, on the eve of the surrender of Japan, was at the final stage of assembly. After a raid on the city of Tachikawa, he was evacuated to the Takahagi airfield in Saitama prefecture, where it was supposed to complete the assembly and conduct a test flight. Here, an incomplete prototype was captured by the Americans. After the end of the war, he was transferred to the United States.
Design work on the assault version of the Ki-93-1b, which was planned to be armed with a 75 mm Type 88 cannon, did not have time to be completed.
The Ki-93 was the last heavy twin-engine fighter built in Japan before the end of the war. The Allies learned of its existence only after the capture of the Japanese Islands, so this aircraft did not receive a code designation.
Armament. In the interceptor version: one 57 mm Xo-402 cannon in the ventral gondola and two 20 mm Xo-5 cannons, a 12.7 mm Xo-103 machine gun in the rear of the cockpit;
As an attack aircraft: one 75 mm Xo-501 cannon, 12.7 mm Xo-103 machine gun and two 250 kg bombs.
Construction. The low-lying all-metal wing of the Ki-93 consisted of a center section, in which two 20-mm No-5 cannons with an ammunition load of 600 rounds per barrel, and trapezoidal consoles were installed on the sides of the fuselage.
The Ki-93's all-metal fuselage was characterized by a very small cross-sectional area. Double cabin. In its rear part, a 12.7 mm No-103 machine gun (Type 1) designed to protect the rear hemisphere was mounted.
Under the center section there were nodes for suspension of two bombs weighing 250 kg each. The most powerful armament of the Ki-93 - the 57-mm No-401 cannon with 20 rounds of ammunition - was supposed to be mounted in a special ventral gondola.
Mitsubishi Na-214 18-cylinder air-cooled engine with 1970 hp. For the most efficient use of engine power, it was equipped with a six-bladed variable-pitch propeller with a diameter of 3.8 m.
On the left wing console - air pressure receiver.