Kawasaki Ki 60

Kawasaki Ki-60[/heading]
川崎 キ60
試作戦闘 / shisaku sentōki/ prototype fighter aircraft

History type:

大日本帝国陸軍航空本部 Dai-Nippon Teikoku Rikugun Kōkū Hombu (command of the imperial army air force) in the late thirties followed the growth of tension in Europe and at the same time, of course, gained important information about air techniques, the scrambling here developed. An interesting finding was the fact that the modern fighter aircraft of the european states was driven, in contrast to the vast majority of the japanese inline engines. Rikugun Kōkū Hombu long considered ordinary engines for the more vulnerable and more demanding on maintenance, and lower the aerodynamic resistance could not, according to this view, the balance appointed by the cons. Another observed fact was the mightier armaments of european aircraft and their greater robustness (compare e.g. the british Hawker Hurricane with the japanese fighter, Nakajima Ki-27a - both planes were created and were built at the same time).

Rikugun Kōkū Hombu took and stubbornly advocated a totally different concept of fighter aircraft. It is true that even here started to grow voices, with an emphasis on higher speed and more effective armament, but this group of officers - technicians have so far been small.
The view command of the army air force for the construction and armament of fighter aircraft is of course reflected in the development and availability of individual structural units and components.

In Japan, for example, at the time, was modern and adequately powerful inline engine. The company 川崎重工業株式会社 - Kawasaki Jūkōgyō Kabushiki Kaisha (hereinafter Kawasaki) was the sole producer of ordinary engines in Japan, but in 1937, it produced only one type of ordinary engine under the designation Ha-9, it was improved the German engine BMW VI, but for modern fighter aircraft are no longer sufficient and had even more performance potential. This engine powered dvojplošné fighters the Kawasaki Ki-10 from the year 1935, was installed in the prototype jednoplošného fighters the Kawasaki Ki-28 from the year 1936 (unsuccessful rival against the Ki-27) and finally powered light bombers Kawasaki Ki-32 from the year 1937. The company Kawasaki has been a long term promoter and a traditional producer of ordinary engines, the development of purely their own type of engine, however, would be lengthy and the outcome uncertain, therefore, decided by the management of this company, that will on its own initiative search for suitable foreign partner for the purchase has already proven the ordinary engine. The choice, however, was not simple. The british had very good engines, but Japan had with Britain rather strained relations, the French zestátnili industry and good engines was the lack of Italians good ordinary engines shouldn't and neither were the Americans. Left Germany, but it quickly and powerfully zbrojilo and had no engines to spare, the Japanese managed to negotiate the terms of cooperation until April 1940, when it was negotiated contract between the Kawasaki and the factory Daimler-Benz of Stuttgart. The japanese purchased a few tens of model engines and the rights to license production of the German invertních dvanáctiválců DB 601A. The first piece of this engine was at the Kawasaki completed in July 1941 under the designation Ha-40. Japan thanks it was a powerful inline engine of modern construction.

A similar situation was with the air cannons, the japanese factory supplied in the mid-thirties only machine guns caliber 7.7 mm, these guns had their pattern in british machine guns Lewis and Vickers, but as I already wrote, the cannon armament of the Rikugun Koku Hombu had no interest. Also here had to later help the supply of guns MG 151/20 from Germany, because the japanese air cannons Him-1 and Ho-3 were inefficient, too bulky and heavy, great and powerful cannon Him-5 came much later.

Eventually the time changes also in the conservative japanese army air force, end of the year 1938 was the unprecedented thing - has been ordered development of the overflow tank Nakajima Ki-44. The emphasis here was placed on high speed, rate of climb and the japanese ratios have to bear the good arm four machine guns (still did not correspond to the european counterparts, we skip to the Italian fighters). The development of this overflow fighters was simple, the aircraft suffered from many childhood illnesses and the japanese pilots rejected him, because they weren't used to the high wing loading of the wing and all the associated flight characteristics. Nakajima Ki-44 Shoki, however, mass-produced and a total of was built 1 225 aircraft of this type.

Kawasaki company is constantly trying to make Rikugun Kōkū Hombu changed its mind on ordinary engines, pointing to the european theater of war and in the end she succeeded, in February 1940 the headquarters of the army ordered the Kawasaki the development and construction of prototypes of the overflow jets powered by a German engine DB 601A. Notice that this happened a full two months earlier than the Kawasaki completed its meetings in Stuttgart. I have to add that the next input on the development of the overflow fighter Ki-60, the army air force has ordered, with a bit of providence, also the development of univerzálnějšího fighter aircraft with a larger span. This second project was marked in the the system Kitai as Ki-61, but had no such priorities as the Ki-60.

Work on the project spill fighter Ki-60 took two factory designers, engineers, Takeo Doi and Shin Owada. The requirements, which the japanese army air force should have been at a high level, e.g., the maximum speed should be at least 600 km/h, the plane had a good climb, carry an effective cannon armament, and was further required good passive protection for the pilot, the fuel tank should be self-locking. I'll be back to the desired cannon armament, as we know, the japanese army air force then had in its arsenal reliable and powerful air cannon from Germany has managed to bring several hundred aviation dvacetimilimetrových cannon MG 150/20, including adequate supplies of ammunition. Engineer Takeo Doi was at that time already an experienced aircraft designer, the program of the Ki-60 had a high priority, and so the work progressed quickly forward, in march of 1941, was completed and ready for testing the first prototype of the Ki-60.01.

Dolnoplošný aircraft looked very robusně and bojechtivě, wings with small span this robusnost hull was underlined, as well as a large radiator fluid under the cockpit. To the japanese standards, it was really a very unusual aircraft, above the engine were two recently introduced machine guns the Ho-103 the caliber of 12.7 mm and in the wings two cannons MG 151/20, therefore, the armament which could bear comparison with all the foreign fighters. Unfortunately, already the first flight test revealed a number of serious shortcomings. The biggest problem was the high value of surface loading, the test pilots constantly make it more difficult on the high landing speed, for a little maneuverability, agility aircraft compared to a heavy bomber and even the supposedly maneuvered better. Aircraft with such a "nejaponskými" flight characteristics could be a popular machine and so was a constant target of criticism. Considerable disappointment for its creator was also a small performance of the aircraft, the maximum speed does not exceed the value of 548 km/h.

Takeo Doi decided that they would try to improve the flight characteristics and the second prototype Ki-60.02 increased the wing area of 0.3 m2, on the engineers tried to better shape the fairing of the engine, it brought a slight speed increase (about 12 km/h), also agility has improved slightly.
The third prototype of the Ki-60.03 brought next even more aerodynamically improved cowling and unloading of the airplane - wing cannons were replaced by velkorážovými machine guns Ho-103. The rate has risen to 570 km/h, it is the army air force seemed to be too little and the whole project at the end of 1941 stopped.

Fortunately, he was in reserve another project univerzálnějšího fighter Ki-61, which had got into mass production. After stopping the project Ki-60 priorities have shifted to this plane with a bigger wingspan and lower surface load, but with weaker armament.

Personally, I think that a quick and definitive end to the development of the overflow fighter Kawasaki Ki-60 was not very happy solution and it was early, test and military pilots demanded from the overflow of fighter manoeuvrability, which, for the capture of an enemy bomber certainly wasn't the most important feature. The japanese army air force later missed the aircraft, which would be able to reliably capture and subsequently destroy ameriké bombers Boeing B-29 and in addition could already be available in the necessary quantities.
German fighter aircraft Bf-109F-3 was produced in the same time and had a wing loading 169,51 kg/m2, but was powered by a more powerful version of the engine DB 601E (1 300 of) and "Frederick" was, according to many pilots considered the best of all the "stodevítek".
Eventually, even the Ki-61 Hein in its latest version Ki-61-II KAIa had a wing loading no longer on the value of 189 kg/m2.


sources:
René J. Francillon Ph. d., Japanese Aircraft of the Pacific War, Naval Institute Press, Annapolis, Maryland, USA, Reprinted 1990; ISBN: 0-87021-313-X
René J. Francillon, Profile Publications, The Kawasaki Ki-61 Hein, Aircraft Profile No.118, 1969
Vaclav Nemecek, Military aircraft 3. Our troops, Prague 1992, 3. supplemented edition, ISBN 80-206-0117-1
Famous Aircraft of the World. Army Experimental Fighters, Bunrin-Do., Japan, ISBN4-89319-021-0
Tadeusz Januszewski and Adam Jarski, Kawasaki Ki-61 Hien, Monograph Lotnicze 5. Gdańsk, Poland: AJ-Press, 1992. ISSN 0867-7867.
http://www.airwar.ru/enc/fww2/ki60.html
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