Kawasaki Ki-61 Hien, tier VI
The Kawasaki Ki-61 Hien was ordered in the winter of 1940, when the company received a commission from the Koku Hombu Army Air Headquarters for two planes: the heavy interceptor Ki-60 and the light fighter Ki-61. Both of the planes were supposed to be powered with the license-built copy of the German DB 601 engine, the Ha-40.
The first prototype of the Ki-61 was completed in December 1941. This unusually long development time can be explained by the fact that the Ki-60 was developed first, while the design work on the Ki-61 did not begin until late 1940 and, in fact, included improvements and adaptations from the parallel project. The fighter proved to be successful: it had the higher speed and altitude, and the increased wing loading allowed for a significantly more enhanced armament. A lot was done to increase durability: the aircraft was equipped with self-sealing fuel tanks, an armored windshield, and an armor plate behind the pilot. These upgrades, however, slightly reduced maneuverability.
The Ki-61 was praised by test pilots, but was viewed with skepticism by the senior officers of the Koku Hombu who still preferred light and maneuverable planes. To address these concerns, Kawasaki staged a fly-off between the new fighter and the Ki-43, the pre-production Ki-44, the captured LaGG-3 and Curtiss P-40, as well as the Messerschmitt Bf 109 E-3. The Ki-61 proved it was an excellent fighter outperforming all rivals and being inferior only to the Ki-43 in maneuverability, which wasn’t a surprise.
The weakest spot of the plane turned out to be its engine. First of all, by the time the plane entered service, its inline Ha-40 engine was already underpowered and required an upgrade (accomplished by fitting late modifications with the license-built copy of the DB 605). Secondly, the Ha-40 was lighter by 30 kg, which raised requirements for the precision in manufacturing engine parts and for the quality of materials. It was difficult for the Japanese manufacturers to ensure consistent high quality in mass production. As a result, the engine broke down all the time and required complicated maintenance and repair by qualified mechanics, which were scarce at the time. Upgrading the engine to the Ha-140 only exacerbated the situation. In addition, after the engine factory in Akashi was destroyed, these engines became scarce.
Nevertheless, the Ki-61 proved to be a good fighter during service in the Pacific theater. In air duels, it outclassed the P-40 and P-39, and only the massive introduction of the P-39 Lightnings, F6F Hellcats, and P-51 Mustangs allowed the Allies to counter the Japanese pilots. Initially, its weak armament was sufficient to combat enemy bombers. However, introduction of the U.S. B-29, capable of flying at a higher altitude and with better armor, forced the Japanese to use the Ki-61 in an unconventional way. In the latter half of 1944, the Japanese pilots started to specifically ram the bombers at high altitude. For this purpose, the fighters were further lightened by stripping their fuselage armament. By the end of World War II, the Ki-61 was used only as a kamikaze and training aircraft.
In WoWP, the Kawasaki Ki-61 is quite a fast and maneuverable plane, designed for air duels. In tier VI, the branch of Japanese Army planes sees the first break point: the Ki-61 is not the most maneuverable fighter in its tier. But it is good at conserving energy in turns, shows good dive performance, and has increased altitude performance and lower flammability. The Ki-61 is very similar to the Bf 109 in its flying behavior, except for the better handling and lower firepower. The key aspects of the aircraft are low boost performance and susceptibility of the engine to critical damage, which reflects the peculiarities of the real aircraft. The armament, which consists of two 20 mm cannons and two 12.7 mm machine guns in top configuration, is quite weak, but has increased accuracy. The fighter can eliminate almost any adversary when controlled by a skilled pilot. The main thing to remember is, as usual, to avoid enemy fire.
Nakajima Ki-84 Hayate, tier VII
Three weeks after the attack on Pearl Harbor, the JAAF turned to the Nakajima company to develop a new promising fighter that was intended to replace the Ki-43, which was just entering service, and to outclass all known existing and still to be completed aircraft of the enemy. The main requirements were as follows: keep maneuverability high comparable to that of the Ki-43, increase durability and firepower.
All the requirements were fulfilled: the plane presented in March of 1943 showed high speed and rate of climb, and was equipped with protection for its fuel tanks, canopy, and pilot seat. It also carried two large-caliber fuselage-mounted machine guns and two wing-mounted 20 mm cannons. All without significantly affecting the aircraft’s maneuverability. It was a meaningful step forward, compared to the fragile and weakly armed Hayabusa. Later the fighter was upgraded to carry a pair of 20 mm and a pair of 30 mm cannons that made it a formidable adversary even for the B-29 Superfortress.
However, as was the case with the Ki-61, the poor industrial base took its toll. By the time the Ki-84 entered service, the Japanese industry was already seeing problems with the supply of high quality materials and a lack of qualified mechanics. This resulted in a high number of engine failures for the Hayate and poor performance of its engines in general. The engine that was supposed to reach a speed of 624 km/h could barely achieve a speed of 400 km/h. Regular failures, oil and hydraulic fluid leaks, as well a shortage of well trained pilots by the end of the war, determined the low combat performance of this plane. Despite all this, the U.S. pilots considered the Ki-84 to be the best Japanese fighter during World War II, based on its airframe, handling performance, and combat abilities.
In the game, the Nakajima Ki-84 Hayate is another aircraft in the branch that changes its paradigm: its flight characteristics cannot be considered as direct improvements of the characteristics of the preceding model. The Ki-84 is different: it is a mid-altitude plane with excellent horizontal maneuverability and quite accurate armament for close combat. Of all its "brothers", it is closest to the Ki-43, and of all aircraft of other nations—the La-7, but with a higher altitude and dive performance. This fighter is most effective at low and mid-altitude: there is no point in climbing high up in the sky in this aircraft. Like its predecessor, it suffers from an unreliable engine, which is reflected by a short and not very dynamic boost.
Tachikawa Ki-94-II, tier VIII
Development for the high-altitude fighter, Tachikawa Ki-94-II, started at the end of 1943 to counter the raids by the high-altitude U.S. bombers. For this purpose, it was supposed to be equipped with a powerful turbocharged engine, pressurized cockpit, and large-caliber cannons capable of combating the durable B-29. The initial order included three prototypes and 18 pre-production aircraft. By the end of the war, only one prototype was completed, though it did not see its first flight scheduled on August 18, 1945.
Later the prototype was taken by U.S. specialists to the U.S.A. for investigation and then handed over to one of the aviation museums where its trail was lost.
The in-game Ki-94-II will inherit the character of the preceding Ki-84 Hayate. This plane is capable of flying at a high altitude, which allows it to fly comfortably at mid-altitude as well climb higher to counter high-altitude adversaries. Its armament has increased accuracy and comprises a pair of 20 mm and a pair of 30 mm cannons with medium firing range that, despite not dealing massive damage per second, fire accurately and for quite a long time. Its high maneuverability will easily allow the plane to counter any fighter in one-on-one engagements, but it requires more caution compared to the aircraft of lower tiers: jet-powered heavily armed adversaries of tier VIII can come out of the blue, and the fragile Japanese plane may not be able to react in time.
Tachikawa Ki-162, tier IX
Development for promising Japanese jet fighters during the late months of World War II was based on pre-existing solutions used by the Germans. According to some sources, this principle was applied to the development of the Ki-162. The project was supposed to be based on the Heinkel He-162. However, unlike many other Japanese projects that used the technical documentation, blueprints, and drawings sent by the Germans via submarines or couriers, the Japanese engineers had extremely limited data to create the Ki-162. The plane was supposed to be equipped with the Japanese Ne-130, Ne-230, and Ne-330 engine and Japanese armament. Basically, the He-162 only inspired the Ki-162. The project was discontinued at an early stage since other jet aircraft, some of which were considered promising, were in development simultaneously.
The in-game Tachikawa Ki-162 will be the embodiment of all the characteristics we want to distinguish in the fighters of the Japanese Army. This plane with a small outline has very high-for-its-tier maneuverability, as well as good dynamics and energy conservation performance in turns. These make it a tough adversary in engagements, where a firefight lasts for only a few seconds. The Ki-162 is most effective at mid-altitude, however, its boost will be enough to chase adversaries heading upward for a short while. The armament of this fighter is typical of the branch: two 30 mm cannons with high accuracy and medium firing range. This fighter will not be able to destroy the target with one hit, but it will easily tie up an enemy aircraft and take it to pieces by dealing critical hits. Of all the aircraft in the branch, this plane is the most similar to the Ki-43, with its handling performance, accurate cannons, and low durability.
Tachikawa Ki-162-III, tier X
A hypothetical development for the Ki-162 project. This top-tier Japanese Army fighter is powered by two engines and advanced armament. Its specifications are upgraded specifications of the tier IX fighter. The Ki-162-III has higher dynamics, more powerful armament, and higher altitude performance. The plane is also highly maneuverable and easy to control. It is an excellent plane for those players who like intense turning battles, and for the cautious players who prefer to evaluate the overall battle situation, pick a target, and eliminate it.