Japanese jet or rocket Interceptor "Suzuka-24"

[airman]

https://sensha-manual.blogspot.com/2017/10/ohka-based-interceptor-fighter.html about Ohka and Suzuka24

 

[Dilandu]

https://sensha-manual.blogspot.com/2017/10/ohka-based-interceptor-fighter.html about Ohka and Suzuka24

The data is highly dubious - mainly, where exactly Japanese get liquid-fuel rocket engine of sufficient power?

 

[Wowness]

https://sensha-manual.blogspot.com/2017/10/ohka-based-interceptor-fighter.html about Ohka and Suzuka24

The data is highly dubious - mainly, where exactly Japanese get liquid-fuel rocket engine of sufficient power?

They did get an Me-163's engine from Germany, and it wouldn't be much of a stretch for someone (probably unofficially) in the IJN to not want to rely solely on the J8M for a rocket fighter and see if a version (scaled down) could be made for the Ohka as a back-up. Since they only got one copy of the engine and had to reverse-engineer it anyway, why not take the opportunity to explore all of your options on how it could be adapted. Speculative, but the time frame for the development for both aircraft does overlap, so it's logical to guess at some point some lateral thinking considered combining aspects of aircraft intended to be powered in the same way, especially if more than a few looked at the Ohka and questioned why it wasn't being used as a fighter too. The experiment probably wasn't a thrilling success, but I'd still be willing to accept that some renegade engineers and airman might have tried it to see if it could be done.

 

[Dilandu]

They did get an Me-163's engine from Germany, and it wouldn't be much of a stretch for someone (probably unofficially) in the IJN to not want to rely solely on the J8M for a rocket fighter and see if a version (scaled down) could be made for the Ohka as a back-up. Since they only got one copy of the engine and had to reverse-engineer it anyway, why not take the opportunity to explore all of your options on how it could be adapted.

Theoretically possible, but the timeframe doesn't feels right.

 

[QAZ]

As soon as the KR10 engine was safe to use it was immediately reserved for the Shuusui in both the Army and Navy. It was not possible in early 1945.

 

[World B4]

I don't think focusing on "ball of light" phenomenon will really provide any breakthrough, if the aircraft was found in multiple examples on 3 airfields by the U.S. Army, as they reported, then any evidence will probably come from photos of said airfields and the ohkas they contained. I personally think that the army found anti-ship ohkas with 20mm guns, and the Japanese lied about the purpose of the weapon. Supposedly, the main physical difference was the tail assembly, but like presumably everyone else I haven't seen any photos of such.

 

[Dilandu]

army found anti-ship ohkas with 20mm guns,

But for what purpose anti-ship Ohka may be equipped with 20-mm guns? Especially considering that there is no space to put them without removing (or at least significantly reducing in size) the warhead?

 

[World B4]

army found anti-ship ohkas with 20mm guns,

But for what purpose anti-ship Ohka may be equipped with 20-mm guns? Especially considering that there is no space to put them without removing (or at least significantly reducing in size) the warhead?

My apologies, I thought there was such a version prototyped, presumably for handling any allied fighter that tried to commit counter-suicide. I looked it up, the suzuka-24 sensha post mentions such a machine but not anywhere else it seems.

 

[Tzoli]

Isn't that be a rear firing gun to fend off interceptors and fighters?

 

[Dilandu]

My apologies, I thought there was such a version prototyped, presumably for handling any allied fighter that tried to commit counter-suicide. I looked it up, the suzuka-24 sensha post mentions such a machine but not anywhere else it seems.

I seriously doubt that. For the barely-trained kamikaze pilot, even just evading the interceptor would not be easy. Trying to ward off interceptor by gunfire... would require skills much more advanced, than Japanese were willing to committ to Ohka's missions. Considering the Ohka's extremely limited engine burning time, the best anti-interceptor tactics would be to just press the assault, relying on speed and back armor. By trying to maneuver, Ohka would inevitably lose speed, and became much simpler target.

 

[Dilandu]

Isn't that be a rear firing gun to fend off interceptors and fighters?

Even if such gun would be installed, how would the pilot be able to aim it, while simultaneously controlling the Ohka itself?

 

[World B4]

Isn't that be a rear firing gun to fend off interceptors and fighters?

Even if such gun would be installed, how would the pilot be able to aim it, while simultaneously controlling the Ohka itself?

I mean if the plane isn't in the Ohka's path it's not really a problem.

 

[QAZ]

A plane with the characteristics of "Suzuka 24" Oka interceptor was never recovered after the war.

The story of Suzuka 24 is based entirely on unreliable wartime intel with inconclusive "supplementary data", like POW quotes, blurry aerial photos, and vague data about J8M/Ki-200.

 

[World B4]

"The land version used the same warhead than the naval one but it was armed with two Type 3 machine guns of 13 mm with a rate of fire of 800 rpm located between the warhead and the fuel tank, which capacity had been reduced to 300 lt, and a combat range to 200 km. The guns configuration was inspired by the German air to air rocket bomber Sombold So 344 project and its objective was that the Ohka could break its way towards the Allies Task Forces fighting against the defensive fighters to which it was equal in speed. The ‘Otsu’ kept the mechanism to detach the wingtips of the naval version but was not considered a requirement to equip it with accelerator rockets for the terminal dive. It was expected that it would be able to surpass the 900 kph in a 50º dive with the Ne-20 at full throttle."

from https://www.secretprojects.co.uk/threads/japanese-jet-engines-of-wwii.34595/page-2
Describes a Model 43 version

 

[QAZ]

"Ouka Model 43 Otsu" is purely a special attacker without any firearms. Despite being jet-powered, it's also very unlikely that it would have been similar in speed to contemporary Allied prop fighters. The suggestion that such a configuration was inspired by a German vehicle is baseless speculation...

 

[T. A. Gardner]

I would presume they are using a Walther engine clone with limited fuel sort of like say a Bachem Ba 349 Natter. Sort of a manned SAM semi-suicide missile cum piloted aircraft. The Walther 109-509 engine really isn't that big or heavy. It's the fuel that takes up all the space.

 

[Dilandu]

I would presume they are using a Walther engine clone with limited fuel sort of like say a Bachem Ba 349 Natter. Sort of a manned SAM semi-suicide missile cum piloted aircraft. The Walther 109-509 engine really isn't that big or heavy. It's the fuel that takes up all the space.

Why not the solid-fuel engine of the original Ohka? It seems to be much more safe bet. If they removed the warhead & installed guns instead, they reduced the launch weight for more than 50%. With some boosters to took off the ground, the solid-fuel Type 4 rockets would be enough to boost Ohka on the interception altitude, from which it could glide toward the target.

Or - if it was launched from carrier plane - they could not bother with additional engines at all.

 

[World B4]

baseless speculation

I forgot to put it all in quotation marks, there's a bit of speculative art on the thread of it too. If there probably isn't a "Suzuka-24", and this was only a paper project if it even was a real thing, I wonder what was found at the airfields that wasn't a standard ohka?

 

[T. A. Gardner]

I would presume they are using a Walther engine clone with limited fuel sort of like say a Bachem Ba 349 Natter. Sort of a manned SAM semi-suicide missile cum piloted aircraft. The Walther 109-509 engine really isn't that big or heavy. It's the fuel that takes up all the space.

Why not the solid-fuel engine of the original Ohka? It seems to be much more safe bet. If they removed the warhead & installed guns instead, they reduced the launch weight for more than 50%. With some boosters to took off the ground, the solid-fuel Type 4 rockets would be enough to boost Ohka on the interception altitude, from which it could glide toward the target.

Or - if it was launched from carrier plane - they could not bother with additional engines at all.

Liquid fuel engines can be throttled and will run longer than solid fuel ones of this period. If you want an interceptor you need several minutes of run time on the motor to get a useful intercept envelope. The Ba 349 is that way. You boost it to altitude on solid fuel then fly downrange on liquid fuel.
Many of the early SAMs used that combination. It is workable for subsonic aircraft as well.

You need like a 20 mile + intercept range to allow for good coverage of the target being defended and to allow several sites to launch against a raid.

 

[QAZ]

baseless speculation

I forgot to put it all in quotation marks, there's a bit of speculative art on the thread of it too. If there probably isn't a "Suzuka-24", and this was only a paper project if it even was a real thing, I wonder what was found at the airfields that wasn't a standard ohka?

Sorry, my last wording was a bit aggressive.

Regarding "photos of Suzuka 24 on airfields": as mentioned in the reports these are merely aerial recon photos, which will be unclear. Assuming scale was correctly measured, it can be said there was "something vaguely Oka-shaped, a bit larger than the US thought an Oka is supposed to be", but that is all.

I have a feeling these objects might have been Akigusa gliders, despite the large difference, but that's my own speculation.


As I previously said, having seen each US report regarding 'Suzuka 24', my opinion is that it's only the result of the perfect storm of cursory data. There is no compelling hard evidence among this, and I think there is little reason to consider it real.

To be clear, I assume it was caused by the conflation of:

- early intel data about the Ōka Mod.11 & Shūsui
- data from a POW who was aware of Shūsui & Ōka Mod.22
- aerial photos of Akigusa or mismeasured Ōka
- ball of fire phenomenon

 

[World B4]

baseless speculation

I forgot to put it all in quotation marks, there's a bit of speculative art on the thread of it too. If there probably isn't a "Suzuka-24", and this was only a paper project if it even was a real thing, I wonder what was found at the airfields that wasn't a standard ohka?

Sorry, my last wording was a bit aggressive.

Regarding "photos of Suzuka 24 on airfields": as mentioned in the reports these are merely aerial recon photos, which will be unclear. Assuming scale was correctly measured, it can be said there was "something vaguely Oka-shaped, a bit larger than the US thought an Oka is supposed to be", but that is all.

I have a feeling these objects might have been Akigusa gliders, despite the large difference, but that's my own speculation.


As I previously said, having seen each US report regarding 'Suzuka 24', my opinion is that it's only the result of the perfect storm of cursory data. There is no compelling hard evidence among this, and I think there is little reason to consider it real.

To be clear, I assume it was caused by the conflation of:

- early intel data about the Ōka Mod.11 & Shūsui
- data from a POW who was aware of Shūsui & Ōka Mod.22
- aerial photos of Akigusa or mismeasured Ōka
- ball of fire phenomenon

You fool, it was aliens.

 

[Foo Fighter]

They came all the way across the channel just for that?

 

[iverson]

You fool, it was aliens.

I wish you people would stop blaming us for everything.

 

[T. A. Gardner]

You fool, it was aliens.

I wish you people would stop blaming us for everything.

 

[dan_inbox]

Would it be a better idea to keep all such OT and unprofessional "witty" remarks for the Bar section?
They do nothing to improve the signal/noise ratio of the serious sections.

 

[World B4]

army found anti-ship ohkas with 20mm guns,

But for what purpose anti-ship Ohka may be equipped with 20-mm guns? Especially considering that there is no space to put them without removing (or at least significantly reducing in size) the warhead?

In the book Japanese Special Attack Aircraft & Flying Bombs, it is explained that the Myojo-Kai special attack aircraft was intended to mount 2 20mm guns for rangefinding, due to poor judgement of distance being a significant factor in failed sucide attacks.

 

[Airborne2001]

There's a lot of stories from the US side of the war regarding the Ōka being used against B-29s, or nondescript "rocket planes". Both in documented combat reports and from the recollection of crews.

From the records of the Japanese side it's known that there was not an interceptor model of the Ōka actually developed, although it seems like there were preliminary plans at points. There's no known record of the standard Ōka model being used against the B-29 either.
If we consider the possibility anyway, wouldn't it be quite difficult for a laden G4M2 to get to an interception position against the B-29 to launch?

Most or all cases are probably explained by overactive imagination, and/or air-launched rocket bombs, or perhaps even RATO units equipped to piston fighters to aid the interception ability. Similar things were tried. The data the US side used to speculate an Ōka interceptor seems to have been mainly based on unclear information about the Shūsui mixing with the Ōka.

---

But, I don't think it's necessarily out of the question that a rudimentary weapon of sorts could have been attempted and simply forgotten, so I'd like to entertain the possibility. There were a few of this kind of weapon developed in Japan, most can be confidently ruled-out as unready by the end of the war, but a couple have almost no surviving information even in Japanese sources.

In terms of the engine, it would most likely need to be a powder rocket, meaning a very short power-time and needing a mother aircraft to bring it to launch. I'm certain no turbojet could have been used in such a weapon, and would not give a bright 'fire' anyway. The liquid rocket 'KR10'/'Toku-Ro Mk.2' was barely useable at the end of the war, and absolutely prioritized for the 'Shūsui' fighter.
The Army had developed the liquid rocket 'Toku-Ro Mk.1' in later 1944, this is the only alternative that could have a somewhat lengthy time of propulsion, but not long enough to make it an independent vehicle.

A few candidates and those which can be ruled out. Mainly, I am listing these to clear up some confusion:

A type of 'Ōka' with liquid-rocket or turbojet:
Simply put, it's very unlikely that such a development went unrecorded in Japan, and there was not really a suitable power unit at the time. The Ōka had originally been proposed with a liquid rocket engine, but the type that was actually completed would need a significant redesign to store enough fuel for useful interception time.

Funryū
This is a SAM developed by the IJN, there were models with either a powder rocket or liquid-rocket, but it was not ready by the end of the war, and never used in combat.

'Winged Rocket'/Shūsui-type Rocket
An unmanned power-rocket propelled ramming body that was similar in form to the J8M Shūsui, but it was not built by the end of the war.

Special Small Bomber
This was evidently a Navy unmanned missile/flying bomb of sorts with a 530 kg warhead and rocket with about 9 seconds of burn time. It was to be used against bomber formations. There is nothing else known about the machine other than that there was a small and large model. It's not clear if it was manufactured.

Sa-Gō
This was an Army air-to-air unmanned guided missile with a liquid rocket giving propulsion, almost certainly Toku-Ro Mk.1. It was developed in 1944, the first unit was supposed to be completed by Mitsubishi in August (putting it on a similar timeframe to the I-Gō anti-ship guided missile, which was considered practical by the end of the war), but it's unclear what actually resulted.

---

I've seen some interesting things in allied intelligence papers regarding their own curiosity on the phenomena. Apart from the 'Suzuka 24' theory, there was apparently a report captured in the Philippines about a sonic-guided missile with bamboo construction. I'm fairly confident I remember reading about a Ki-67 supposedly being shot down while carrying a "robot bomb" as well.

In the future I'm going to try to compile all the related info on this subject and make a comprehensive writeup.

Absolutely fascinating. Thank you for sharing. If you have completed this write-up I would love to see it because this is the first time I am hearing about quite a few of these projects (like the Funryu) and rumors (like that "robot bomb").

While it is sad to see that the Suzuka 24 may be fiction, I do agree with some posters that it would not be surprising if Japan considered something of the suit at some point. It would be the ultimate "desperate" fighter, even more so than other rocket fighters simply due to it being built from a kamikaze aircraft.