KI-64 japanese VB.10

[Would you like to see this in-game?]
  • Yes
  • No
0 voters
[How it is to be armed]
  • Armed with 2 Ho-103 and 2 Ho-5
  • Armed with 4 Ho-5 cannons
  • Possibility to replace the armament as in the Ki-43
  • I said no
0 voters
[what version to add (it’s best to read the whole suggestion)]
  • ki-64
  • ki-64 kai
  • no
0 voters

Kawasaki Ki-64
Let me start by telling you what the Ki-64 is.It is a prototype Japanese fighter aircraft of World War II designed by Takeo Doi at Kawasaki. The aircraft had an unusual propulsion system consisting of two interconnected engines driving counter-rotating propellers and an equally unusual engine cooling system across the entire wing surface. Only one prototype was built, the project was abandoned in 1944.
History and Structure description
The history of the Ki-64 begins in 1939 when Kawasaki’s Takeo Doi began developing his own design for an experimental plane due to problems with his current design, the Ki-45. Unfortunately, as it was his own design, was not given the opportunity to develop it by the Army until October 1940, when the Army became interested in the project and accepted it as the Ki-64.
photo of Takeo Doi 1945^
However, requirements were imposed for the design, the aircraft was to fly at a speed of 700km/h at an altitude of 5000m and had to reach this altitude in 5 minutes. The Army wanted to make this aircraft a fast heavy interceptor. To meet the speed requirements, a powerful aircraft engine was needed, which was not available in Japan at this coin, so Kawasaki asked engineers from the Akashi engine company for help.It was there that they came up with the idea of combining two new Ha-40 engines (DB 601 engine license) with a common propeller shaft. It was called the Ha-201 engine, which had a take-off power of 2,350 hp and 2,200 hp of nominal power at an altitude of 3,900 m. The engines were to be mounted behind each other in a line, one in the nose of the aircraft and the other behind the pilot, and not as usual in two-engine aircraft on the wings, which significantly reduced the central part of the aircraft.At the beginning, there was an idea to mount them next to each other, as in the Macchi MS.72 aircraft or the experimental “C” bomber from the Soviet Union, but such a procedure strongly moved the cockpit back, so it was abandoned and made similar to the concept of the Arsenal VG.10 aircraft. A similar feature to this aircraft appears, i.e. double counter-rotating propellers. A rear-mounted motor drove the first variable-pitch propeller in the counter-rotating propeller. The front engine drove a second propeller that had a constant pitch. Both propellers were three-bladed. They were out of sync with each other and each worked independently of the other.This engine needed cooling, so the engineers, inspired by the cooling system from the He 100 aircraft delivered in 1940, used a similar system. Water tanks with a capacity of 68,191 litres were installed in each wing console, which, together with the flaps, served as cooling surfaces with a total area of 24 m2. The left wing console operated the front engine, while the right console supplied coolant to the rear engine.When the cooling water turned to steam, it was pumped out to the wing, where the steam condensed back into water, which in turn was pumped back into the engine. The main benefit of this system was the reduction of airframe drag, as the need for air intakes was eliminated or minimized.However, everything has its pros and cons. With the cooling system and armament mounted in the form of a single Ho-5 cannon, there was little room for fuel tanks in the wings.Most of the fuel was placed in the fuselage – the tanks were located in and around the space left by the Ha-201’s slow engine. The main fuel tank, with a capacity of 306.7 liters, was located at the front of the fuselage in front of the cockpit. Underneath was an oil tank that held 79.5 liters of engine oil.The oil cooler was common, standing asymmetrically, under the right wing. As it was not possible to achieve a good seal of the cooling system, there were two expansion tanks with coolant behind the cockpit, containing 83.3 and 117.4 liters respectively. The front engine was powered by a smaller one, the rear by a larger one. The project was not completed until January 1943 due to work on the Ki-60 and Ki-61.On 23 January, the Army ordered a prototype aircraft, but work was delayed due to a problem with the propeller shaft vibration and due to the complexity of the design.The cooling system was tested on a modified Ki-61 fighter and lasted from October 1942 to the end of 1943, causing further delays in production, to the point that the aircraft was not ready until December 1943. However, Doi was pleased that the Ki-61’s cooling system provided an additional 41 km/h. It was decided that combat damage would not significantly reduce its effectiveness, so it was worth conducting exhaustive tests.Tests of the new design were immediately started and this is where the problems began, because it turned out that the cooling system was inefficient. The plane was shrouded in a cloud of steam during take-off, and finally, during the fifth test flight, the rear engine caught fire. Thanks to the experience of the test pilot, he managed to land and the ground crew extinguished the engine fire.The engine was sent back to the Akasha factory for repair, and the aircraft was taken to the city of Gifu. At this point, the engineers came up with the idea of replacing the twin ha40 (ha-201) engine with a twin ha-140 (ha321) engine, which was supposed to develop 2800hp. In this way, the ki-64 kai aircraft was to be created, unfortunately the war began to go very unfavorably for Japan and engineers were sent to more promising projects.Work on repairing the Ki-64 and creating an engine for the Ki-64 Kai lasted until mid-1944, when the project was suspended. At the time of the surrender, the Ha201 engine was still unrepaired at the Akashi factory, and the aircraft with the cooling system removed was in the hangar in Gifu, where the Americans found it.

Photos of the aircraft

Assembling the prototype^
Ki-64 during take-off^

Ki-64 in flight^

Ki-64 in 1945^

technical sketches

OIP (5)
OIP (1)

Ki-64 kai
The Ki-64 kai was supposed to reach speeds of up to 800 km/h, the front and rear propellers in this unit were not only adjustable in terms of pitch, but also completely weatherproof - installed along the stream, reducing drag when the propeller was not working. This innovation made it possible to shut down one engine during a cruising flight. This innovation made it possible to shut down one engine during a cruising flight.Unfortunately it was only a concept, the engine from the combined two ho140s was never made, and the project was cancelled shortly thereafter.

The armament consisted of two Ho-5 cannons in the wings and two above the engine in the fuselage, or two Ho-103 guns above the engine.It is not known whether there were plans to carry additional weapons in the form of bombs or rockets.
General characteristics

  • Crew: 1 (pilot)
  • Length: 11 m (36 ft 1 in)
  • Wingspan: 13.5 m (44 ft 3 in)
  • Height: 4.25 m (13 ft 11 in)
  • Wing area: 28 m2 (300 sq ft)
  • Empty weight: 4,050 kg (8,929 lb)
  • Gross weight: 5,100 kg (11,244 lb)
  • Powerplant: 1 × Kawasaki Ha-201 coupled liquid-cooled V12 engine, 1,750 kW (2,350 hp)
  • Propellers: 2 × 3-bladed contra-rotating propellers


  • Maximum speed: 690 km/h (430 mph, 370 kn) at 5,000 metres (16,000 ft)
  • Range: 1,000 km (620 mi, 540 nmi)
  • Service ceiling: 12,000 m (39,000 ft)
  • Time to altitude: 5.5 minutes to 5,000 metres (16,000 ft)
  • Wing loading: 182.1 kg/m2 (37.3 lb/sq ft)
  • Power/mass: 2.91 kg/kW (2.17 kg/hp; 4.78 lb/hp)


  • 2 x 20mm Ho-5 cannon in the wings
  • 2 x 20mm Ho-5 cannon in the nose or or two 12.7mm Ho-103 rifles
Sources about armament

American Opinion
After the war, the U.S. military, which studied this aircraft, reported on the results of the study, saying, “The engine arrangement is unparalleled among Japanese aircraft, as it is arranged in tandem and its method of cooling the wings is interesting enough for American designers.”

Incomplete U.S. documentation


Full documentation available for purchase

Sketches and drawings of the Ki-64

OIP (4)
OIP (3)
OIP (2)


The Ki-64 looks like the VB.10C had a child with the He 100 who was raised by the Japanese Ki-61 and Ki-84.This aircraft would be a very interesting interceptor for Japan, with very comparable performance to the Ki-84. Armed with Ho-5 cannons, they are lethal to many planes, and the speed will allow you to escape from some of the enemies.Japan deserves the addition of their many interesting prototype machines that they have created, and unfortunately are overlooked by the creators.
Finally, I apologize for the linguistic and logical errors because unfortunately English is not my main language and I had to use google translator.

Special thanks to the user


Kawasaki Ki 64 - Alchetron, The Free Social Encyclopedia
Takeo Doi – Wikipedia, wolna encyklopedia
Kawasaki Ki-64 (Rob) (
Kawasaki Ki-64 - Wikipedia
Kawasaki Ha40 - Wikipedia
Ha-40 (silnik) – Wikipedia, wolna encyklopedia
キ64 (航空機) - Wikipedia
Kawasaki Ki-64 (“Rob”) Experimental Heavy Fighter | Secret Projects Forum
Japanese Aircraft of WWII: Kawasaki Ki-64
Нереализованная мощь Японии. Опытный истребитель 川崎 キ64 (Kawasaki Ki-64) - Альтернативная История (
Опытный истребитель и экспериментальный самолет 川崎 キ64 (Kawasaki Ki-64). Япония - Альтернативная История (
Ambitna praca Kawasaki, która zarejestrowała 690 km/h w locie testowym “Prototypu szybkiego myśliwca Ki-64”: Blog do czytania w toalecie
Kawasaki Ki-64 Prototypowy myśliwiec szybki | Solidny blog (
Уголок неба ¦ Kawasaki Ki.64 (
Kawasaki Ki 64 [Rob] : Kawasaki (
採用されることの無かった戦闘機たち | ミリタリーショップ レプマート (
Kawasaki Ki-64 Experimental Fighter | Old Machine Press
Ki-64 Heavy Fighter- Interceptor, Rob, Kawasaki (
Kawasaki Ki-64 ROB - fighter (
Samoloty - Inne Oblicza Historii (
キ64 (きろくじゅうよん)とは【ピクシブ百科事典】 (
キ64 (航空機) - キ64 (航空機)の概要 - わかりやすく解説 Weblio辞書
Hikoki:1946 (
一式十二・七粍固定機関砲 - Wikipedia
二式二十粍固定機関砲 - Wikipedia
Heinkel He 100 – Wikipedia, wolna encyklopedia
ATIG-Report-39.pdf (
「キ64」高速重武装戦闘機・・・最大速度780km/hの幻の高性能機 (



I’ve been wanting this plane for a while now. I always ask for it lol. I think the Ki-64 Kai would be good in-game, but given how paper it is, it may be better as an event vehicle like the J6K was


I think this would be really good to add. It would allow Japan to get a “superprop” akin to the Griffon Spitfires, P-51H, G.56, and similar aircraft in other trees.
It really feels like Japan should have a tech tree vehicle at around the ~6.7 range, and the J6K1 is 6.7 and sort of is the “Japanese Superprop,” but it is an event vehicle; so there isn’t one.

1 Like

Was it fully drawn up? Yes
Was it made as mockup? Yes
Was it actually made and even flew? YES
That’s a +1 for me, heck yes


I have good news for those who are waiting for Japanese prototype things or very interesting features.Soon (I don’t know exactly) there will be suggestions for Ki-91, Ki-51 aircraft and AAM-1 and AAM-2 missiles on the forum. In the future, I will suggest interesting things for Japan. Regards, the creator of the suggestion



I was planning to make Ki-64 and Ki-51 suggestions in few weeks, but you seem to be doing well. Didn’t expect anyone else to be that interested about them. For the latter I don’t even have much, which seems to be a common thing with Japanese light bombers.

Luckily Ki-64 is well known apart from the armament. The wing Ho-5s appear in some original drawing and everything seems to agree that there was room reserved for them. I can only guess they would have had 200 rounds per gun, since that was very much a standard feature for late war Kawasaki fighters. Unfortunately the cowling guns are bit unknown. Apparently original sources say the planned guns were Ho-103s. Their supposed location is also little vague, because the front is so tightly packed. The guns might fit, but how about their ammo boxes?

edit: There is at least one original mention about 4x Ho-5. It looks like this was changed to 2xHo-5 + 2xHo-103 later, but I’m not certain.

It’s not unnusual at all for a prototype plane to not have it’s armor data listed, but we know it was a standard feature in IJAAF. Most certainly it would have followed the usual Kawasaki practice: 12mm behind seat and 16mm headrest.


Definitely yes would like to see it. Ed Nash’s Military Matters is one of my favorite aircraft channels and he also did a video on this.


+1. One of my favourite WW2 aircraft.

I think the most impostant thing to note concerning Ki-64 in WT would be the issues with cooling system. Indeed like he mentions, it might not be be extremely fragile, but rather the poor cooling on ground and at slow speed would be an issue. The plane has reasonable climb times stated on papers: 5:30 and even 5:00 in one, but in WT everyone climbs with WEP if possible. With Ki-64 WEP usage at usual climb speeds could be too much for the cooling and higher speeds are simply less optimal. However Ki-64 is a twin-engine fighter and in WT all twin-engine fighters get interceptor spawn, even if they already have very good climb rate like XP-50.


The Ki-64 turned from an experimental aircraft into a heavy fighter that was intended to complement the Ki-45 aircraft. Unfortunately, the Japanese did not succeed and if it were not for jet planes, the cooling system would have been used in the USA


I think you are overestimating Gaijin’s willingness to model it accurately haha


One of my most wanted planes in WT, I was waiting for this suggestion in the new forum. +1000


If I remember right, the model was discovered in game files already in 2019. Makes me wonder why they didn’t release it.

1 Like


A +1 from me, definitely a must add

If i remember correctly the model was never in the files but rather “published” by another Company who also creates models for WT.
But definitly a big 1+ since it existed and looks super sexy.

The Ki 64 also got a Role in “The Magnificent Kotobuki” anime


“A thorough examination of the steampunk high-speed fighter plane Ki-64!”


Seems like there is at least one mention of 4x20mm armament in original documents from Kawasaki. I think 2x20mm + 2x13mm came later.



great job, this will definitely come in handy in improving the ki-64 suggestions