Mansyū Ki-98 - Japanese Saab 21

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Mansyū Ki-98
The Ki-98 was initially developed as an attack aircraft to replace the Ki-51 aircraft. However, due to the intensifying bombing in Japan, its purpose was changed to a high-altitude aircraft. The only prototype was built in Manchuria and in 1945 it was destroyed to avoid falling into the hands of the Red Army. So much for the introduction.
The history of the Ki-98 begins at the end of 1942, when Koku Hombu (Japan’s Air Ministry) was looking for a candidate to replace the rapidly aging Ki-51 aircraft. The competition was attended by a small company, the Manchuria Airplane Manufacturing Company (Manshū), which, although a subsidiary of Nakajima, also made its own designs. The best engineers were engaged in the project, who did not stick to typical design in order to meet the requirements, but went for innovation. The requirements were for the aircraft to be heavily armed and to reach high speed and have a long range. Design of the machine began in early 1943, and the preliminary design was sent to Koku Hombu, who accepted it and gave it the name Ki-98. At this point, the support of IJAF specialists came in and the project was completed in July 1943. Then the construction of the wooden model began, which was ready in December 1943.The finished model was sent to Japan, where aerodynamic tests were carried out on it at the beginning of 1944. Tests showed that the Ki-98 had excellent flight characteristics, so Mansyū began preparations for the production of a prototype. These results were also sent to the Air Ministry, which demanded that the specifications of the Ki-98 be changed from an attack aircraft to a high-altitude aircraft.This sudden change forced changes in the design that delayed the prototype product. Due to Japan’s deteriorating situation, the redesign lasted until October 1944. It was planned that the Ki-98 prototype would be ready in early 1945, but on 7 December 1944 the factory was bombed by B-29s, delaying production of the prototype.Finally, production of the prototype began in mid-January 1945. Production was constantly plagued by delays, and so by the beginning of August, the fuselage, wings and tail booms were ready for assembly. Unfortunately, on August 8, 1945, the Soviet Union, violating the non-aggression pact, invaded Manchuria, Mansyū workers destroyed all documentation and the Ki-98 prototype to prevent it from falling into the hands of the Soviets.
Structure description
The aircraft was very similar to the Mitsubishi J4M aircraft designed at a similar time, although it was slightly smaller. It was a single-engine pusher propeller fighter with a double-spar design. It was to be powered first by an eighteen-cylinder Mitsubishi Ha-211-III air-cooled engine, which was replaced by a Mitsubishi Ha-211 Ru engine which was equipped with a supercharger.The engine was powered by a four-blade propeller which was mounted at the end of the nacelle, it had a two-meter propeller shaft. To cool the engine properly, the air intakes were located front behind the cockpit, they were mounted on the top of the nacelle. To increase the airflow, a fan driven by the engine was additionally mounted in front of the engine. The hot air was expelled through the outlets at the bottom of the nacelle in front of the propeller.The wings with a profile similar to that of a laminar one were mounted in the lower part of the nacelle, from each of them came a thin tail boom, with a vertical stabilizer in the shape of an egg, connected by a horizontal stabilizer, very similar to the P-38. The aircraft used a three-wheeled landing gear, the wheels of which retracted backwards when retracted. The front wheel retracted into the fuselage and the rear wheels into the tail beams.Due to the high altitude at which the cockpit was located, the entrance to it was through a hatch in the floor, which was located where the front wheel retracted. In the initial design, the pilot had a big problem at the moment of critical damage to the machine, because he could only evacuate safely through this hatch, because jumping out in a normal way would end in death after hitting the horizontal stabilizer or the propeller.Later, this problem was solved by a system that fired the propeller and horizontal stabilizer.

Technical sketches




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Comparison with similar aircraft


The armament consisted of two 20mm Ho-5 cannons and one 37mm Ho-204 cannon. They were mounted in the front part of the nacelle in front of the cockpit, due to the lack of space of the barrel they protruded beyond the outline of the nacelle. The 20mm cannons were mounted at the top and the 37mm cannon was mounted below. The amount of ammunition is not known, but it can be assumed that the Ho-5 cannon had 150 rounds and the Ho-204 cannon had about 30 rounds, very similar to the Ki-108.Initially, it was supposed to be equipped with bombs and missiles, but it is not certain whether this option was completely abandoned.
General characteristics

  • Crew: 1
  • Length: 11.4 m (37 ft 5 in)
  • Wingspan: 11.26 m (36 ft 11 in)
  • Height: 4.29 m (14 ft 1 in)
  • Wing area: 23.99 m2 (258.2 sq ft)
  • Empty weight: 3,500 kg (7,716 lb)
  • Gross weight: 4,500 kg (9,921 lb)
  • Powerplant: 1 ×Mitsubishi Ha-211 Ru 18-cyl. fan assisted air-cooled radial engine, 1,600 kW (2,200 hp) for take-off
    • 1,461.6 kW (1,960 hp) at 2,000 m (6,562 ft)
    • 1,305 kW (1,750 hp) at 8,500 m (27,887 ft)
  • Propellers: 4-bladed metal constant speed pusher propeller driven by a 2 m (7 ft) long extension shaft, 3.6 m (11 ft 10 in) diameter


  • Maximum speed: 730 km/h (450 mph, 390 kn) at 10,000 m (32,808 ft)
  • Range: 1,249 km (776 mi, 674 nmi)
  • Endurance: 2 hours 15 minutes at 499 km/h (310 mph)
  • Service ceiling: 10,000 m (33,000 ft)
  • Rate of climb: 15.15 m/s (2,982 ft/min)
  • Time to altitude: 5,000 m (16,404 ft) in 5 minutes 30 seconds
  • Wing loading: 187.5 kg/m2 (38.4 lb/sq ft)
  • Power/mass: 0.5 kW/kg (0.3 hp/lb)


  • 1× Ho-204 37-mm cannon
  • 2× Ho-5 20-mm cannon
  • Bombs and Rockets: ???

The Ki-98 would be very similar to the J7W in terms of performance, so it would be a very interesting interceptor. It will be perfect for destroying bombers and unwary enemy fighters. This design, due to its uniqueness, should find its way into War Thunder and will work great there. I encourage you to leave your opinion in the comments and if anyone has additional information, please share it.
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 for helping the user

Extra Art

The source of this great art:
満州飛行機 キ98 〜離陸〜 | be-yoshioのブログ (
満州飛行機 キ98 〜飛行〜 | be-yoshioのブログ (


Manshu Ki-98 (
05[満州飛行機製造株式会社]満飛キ98試作戦闘襲撃機.pdf (
Project Ki-98 multipurpose fighter (
Kącik nieba ¦ Mansyu Ki-98 (
Hikoki:1946 (
Mansyū Ki-98 / キ98试作战斗袭击机 : Manshu (
Mitsubishi Ha-43 - Wikipedia
Ho-5 cannon - Wikipedia
Ho-204 cannon - Wikipedia
Ha-43 (silnik) – Wikipedia, wolna encyklopedia
Mansyū Ki-98 - Wikipedia
Mansyū Ki-98 – Wikipedia, wolna encyklopedia
USS Ki-98 – Wikipedia, wolna encyklopedia
Mansyu / Manshu Ki-98 (
大昔の軍用機 旧日本軍 その他 満飛 キ98 試作高々度戦闘機 (
Wariant prototypu, który nigdy nie ujrzał światła dziennego (
IJN Mansyu Ki-98 – GUNKANDO (
村正ラボ na Tumblrze: キ98(ききゅうはち)は、第二次世界大戦中に計画された日本陸軍のレシプロ戦闘機である。 キ98は元々は、九九式襲撃機の後継機となる戦闘襲撃機として1943年(昭和18年)に満州飛行機に対して試作指示が出された機体だった。 しかし、B-29…
Mansyū Ki-98 / キ98试作战斗袭击机 : Manshu (
Manshu Hikouki(Manpi) Ki-98 | Secret Projects Forum


This thing is wild! +1

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I want this plane so badly, and for one single reason: it is another platform with the Ho-204 37 mm cannon.



Yet another aircraft i want to see badly for years now +1

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I remember talking about it on the old forum years ago

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Yes yes and again yes. Can’t stress enough how amazing this aircraft is, sad how we have 0 photos of it so it’s going to be tricky to have in game. But one day maybe we’ll see it. +1

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Any WW2 vehicle whose story ends with “so they made a prototype, but then they destroyed it and all documentation” while not having any sort of photographic evidence is extremely sus.


Well it may be but this happend to a lot of things.

For instance we know that the O-I was atleast partialy built but with the end of war it was scraped and almost all documentation destroyed.

The R2Y2 crashed, Kikka bombed to oblivion, most documentation on Yamato class ships burned.


A good example with photos of Japanese secret prototypes is the Ka-Ha electric tank, which was also a secret project, with only one photo confirming its existence
images (1)
His story is the same - at the end of the war, they were all thrown into a big hole and blown up


Yeah, but all those vehicles (maybe not R2Y2) have photographic evidence they existed. Even the O-I has a track link supposedly belonging to it. The suggestion for the Ki-201, a plane that definitely was not built, still has photos of the jet engines meant for it.

You’d think when the Soviets captured Harbin they would’ve gone to the Manshu factory and inspect it, take a few photos of the remains of the Ki-98? Or some enterprising Japanese engineer just kept a photo to himself?

I’m not saying it wasn’t built, it’s just really sussy. There’s another Axis plane like that, the Re.2006 which was also supposedly built, and then captured by the Allies before being scrapped. There’s no photos of that thing either somehow, but apparently a piece of it survives.

Since ehen did r2y2 crash? I thought it just straight up never existed

The R2Y2 V1 existed as prototype with propelor/s and was to be equiped later with jet engines the V2 and V3 didn’t exist. And I got the Kikka wrog it was Kikka which crashed.

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R2Y1 was created, R2Y2 was never created.
images (2)


Oh I see sorry then


You’re thinking of the R2Y1 which was a propeller driven reconnaissance plane (hence the name of the plane starting with R) that was unnarmed.

No R2Y2 prototype crashed because it never got the chance to fly in the first place.

I’ve always been curious how they went from the R2Y1 to something like the R2Y2 which shares not so many similarities with it’s predecessor. I mean the wing structure seems to be the same, the tail might as well be the same, but the rest?

The R2Y2 never flew cause it didn’t exist. The Kikka only 1 still exists. As only 2 were built.
There is still plenty of documentation for the Yamato. Little information proves the claim it was scrapped because we have nothing to go off by.

Jet engines would make a difference.
The fuselage would roughly be the same but the wings would have to be straightened out. Those slightly curved angled wings wouldn’t do well with speed.

Do you have any photographic evidence of this vehicle existing in any capacity? I heard of other Manshu aircraft like キ71 that purportedly existed to the capacity that the allies knew of their doings, but it suffers from the same issue of lack of substantiation for its existence. If i remember this plane if it would have been built to any capacity is like their failed キ65 project

Personally, I couldn’t find photos of the Ki-98, although now I have an additional source, so I have to look more carefully