The Ki48-II-Otsu lacks some issues

As for the nose gunner, it seems difficult. What about bombsights? In the game, players rely on the naked eye to observe missiles and target ships, but according to Mitsubishi, accuracy was improved by using optical instruments for observation.


Optical sight for I-go missile

  • Use Type 94 air reconnaissance optical sight for ranging.
  • Add a tracking telescope to control the I-go missile.

Mitsubishi Heavy Industries Aircraft History. p.600. (Provided by @Lineins)


The Type 94 air reconnaissance optical sight was developed by the Japanese Navy for aerial reconnaissance and was able to measure drift angle, ground speed, distance and speed of target ships. The principle was the same as the prism mechanism of the Type 88 bombsight.

Spoiler

https://i.imgur.com/3kmwVsq.jpg
https://i.imgur.com/COgfaO5.jpg

Japan Optical Industries Corporation History, 1960, p.486

Drawings of Type 93 and Type 94 air reconnaissance optical sight

Spoiler

https://i.imgur.com/oWKnY0G.jpg
https://i.imgur.com/Q7oTabf.jpg

Optical Industry History Editorial Group, History of Japan’s Optical Industry with a Focus on Weapons, 1955, p.320

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Interesting. This sight could definitely be used as a bomb sight, but it could also be implemented to zoom into and track the guided missile, making it easier to aim. I still hope to suggest that the standard Type 88 bomb sight be reinstalled upon equipping conventional bombs, but we’ll see…

Concerning the nose gun, upon closer examination of the Ki-48’s in game model, I found a different structure in the nose:


Whatever it is, It is definitely in the way of the nose gun, and I cannot find it in any photos of standard Ki-48s. Thus, I assumed it was the guidance system, or at least something representing it. Does this look familiar to you?

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more reference added
USNTMJ-200D-0550-0575 Report 0-02.zip (1.8 MB)

@tester188 & @ibaraki_Kasen

The remaining issues have been closed. Of the “missing nose gunner/bombardier” report, only the part concerning the missing nose-seated crewperson (who should be there to guide the Ki-148 missile) was passed. The “missing bomb bay doors” report was rejected.

Per the moderator’s recommendation, I have a suggestion I am working on, which I will post to the forum, outlining how these missing features can be implemented without any unhistorical overlap between the Ki-48 for missile testing and a standard Ki-48, allowing both to be accurately represented in game simply by switching loadouts. I will let you know when I get it posted.

In addition, I also have an idea of a suggestion for implementing the Type 94 reconnaissance sight, which could be used to more accurately aim the missile at larger ranges. @tester188, was the Type 94 sight used not only for ranging, but also for tracking the missile, or was a separate telescope used for tracking the missile? Your source seems to suggest the latter, but I’m not sure. If indeed it was a separate telescope, do you have any information on it?

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being able to track the missile would help a lot if that’s true.

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I was researching books and other information about Ki-148. Specific details regarding the telescope used for maneuvering are not known at this time. BTW, I found information that the Ki-148 had a radio altimeter to maintain its altitude at 30 m.

According to Mitsubishi’s information, the I-go A’s radio altimeter for maintaining altitude did not work well and was removed early on, but according to Kawasaki’s information, the I-go B was equipped with a radio altimeter and successfully maintained its altitude. It was able to detect radio wave reflections from the sea surface at an altitude of 20-30 m and maintain an altitude of 30 m. Some Japanese books explain that the I-go missile was equipped with a radio altimeter.


https://dl.ndl.go.jp/en/pid/4009745/1/84

This primitive sea skimming ability could make it easier to hit enemy players’ ships in games. When I use the Ki-148, it is difficult to judge the altitude when the missile is far from the Ki-48.

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This is interesting, and could be an excellent addition. As you say, this would make hitting enemy vessels with the missile much easier. Combined with a telescopic sight for tracking the missile, a Ki-48 could cause havoc among enemy coastal vessels at a range far exceeding their AA capabilities.

  1. Spawn in and aim the missile slightly downward
  2. Launch the missile and let it get close to the water so that the altimeter can take over
  3. Use the telescope to guide the missile to a target using the horizontal guidance controls
  4. Upon reaching a target, nose the missile down into it to kill it (hopefully)
  5. Repeat

I would assume that the altimeter would only work when the player wasn’t using the vertical guidance controls, so that it wouldn’t interfere when attempting to hit land-based units or low-to-the-water vessels such as PT boats.

On a different note, the moderator that assessed my bug reports made available to me a photograph of the missile guidance system in the nose of the Ki-48, confirming it is the structure I found in the asset viewer images above:
Ki-148 operator

Image provided by user skultew1234.

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I found testimony from a pilot who tested a Ki-148 missile on a Ki-102 Otsu assault plane.

The pilot testified that the Ki-148 is equipped with a radio altimeter and that a missile operator’s seat was added to the Ki-102 Otsu. Based on the testimony, it can be inferred that if the I-Go guided missile is mounted on the Ki-102 Otsu, the crew would increase to three as a missile operator is added. Additionally, the 57mm Ho-401 cannon occupying the nose space would likely be removed.

Should we consider this as a special variant of the Ki-102 Otsu in War Thunder? Gaijin can earn a large amount of revenue by adding a special Ki-102 Otsu model equipped with missiles to the game as an event vehicle.

I was a member of the Army Aviation Review Division, Flight Test Squadron, and participated in the testing of the I-Go guided missile.

The test was conducted from May to July 1945, based at Yokaichi Airfield and targeting an islet called Oki no Shiraishi on Lake Biwa. The yellow painted I-Go guided missile flew over the azure lake with great momentum powered by the rocket engine, and the radio altimeter equipped on the missile made it fly very low over the lake, so impressive that I will never forget the memory. I tested both I-Go A and B. At first I found it difficult to control, but I gradually got used to it and reached 80% hit rate with I-Go B.

Although the number of times was small, the I-Go B missile was tested by Ki-102. In this case, the nose of the Ki-102 was modified to create a seat for the missile operator. The missile operator sits with his legs thrown out in front of him. The entrance to that seat is on the right side of the nose, but it is very small, so he had to lean his body sideways to get in and out. The pilot’s seat and operator’s seat were separated by a wall, which made the missile operator feel very cramped and alone. My superior test pilot was too large to sit in the cramped missile operator’s seat in the Ki-102, but I was relatively small enough to sit in the operator’s seat and test radio command guidance.
(Translator’s note: Abridged translation)

Kiyoshi Iguchi

Source

Spoiler

https://i.imgur.com/yiOGEQI.jpg
https://i.imgur.com/aBlnzXV.jpg
https://i.imgur.com/IMfMVn6.jpg

Source: Kaikō, February 1988, pp.53-54.
(Veterans Association Bulletin)

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It unquestionably requires a more realistic and user-friendly guidance system than the existing external camera on the aircraft. In my opinion, a potential solution could be a system similar to the bomber camera, but with the capability to automatically track the missile’s trajectory from the aircraft, enabling substantial zoom functionality. Indeed, this capability underscores the significance of having a dedicated nose crew, which unquestionably serves this intended purpose.

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Or add an option to ignore the gyro? That way you can use it like any other MCLOS missile in game.

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Fritz X has such. (I know its a controllable bomb and not rocket, but the sight is locked on the bomb.) I thought that this plane would recive the same, cince by the comments above it had a dedicated guidance “scope”.

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Amazing work finding the info about the Type 94 Surveillance Glass and Ki-102 w/ Ki-148 testimony. Very valuable information, thank you!

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I agree. Also, concerning the nose-seated crewperson, a bug report was made and passed to the developers, so we should hopefully see him added in so that he can man the guidance system and any telescopic sight for tracking the missile.

My idea was that there would be a new view that would take the place of bombsight view when the missile is equipped, and which is only available after the missile has been launched. If the telescopic sight used was like the one used in lower-tier Japanese fighters like the Ki-44-I Ko, the zoom available would be very beneficial.

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This is interesting. I had known that the Ki-102 was intended to carry the Ki-148, but I was not aware that such a configuration was actually tested. The testimony says that the nose was hollowed out to make room for a missile guidance crewperson. Does this mean that the nose was replaced with a sort of glass one so that the operator could see and guide the missile? Or was there a scope used by the operator that stuck through the nose?

This is an idea, but given that the radio altimeter was built into the missile, I believe it would have to be toggled before spawning in; it could not be toggled remotely. Nevertheless, such a pre-spawn toggle would be useful for ground battles, where the altimeter would likely get in the way.

It would be a debate, however, whether it would be historically accurate to have the altimeter even be toggleable, but it could probably work in-game anyway.

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In reality, Ki-148 was tested with radio altimeter that automatically lowered and maintained the altitude to just above the surface of the sea. In-game, it isn’t present, probably as an intentional balancing factor, so it can be used against tanks. In reality, Ki-148 will also level automatically at the horizon, but in game it levels at the launch incidence.

According to US documents, radio altimeter was not reliable and was ‘removed’. But Japanese documents or books do not usually mention this. The testimony found by @tester188 also implies that the altimeter was present in tests near the end of the war. So it seems unclear, but I think it’s fine that GJ opted to not include the radio altimeter.

@tester188 said that the altimeter was found to be unreliable and removed from the Ki-147, but that it was successfully used in the Ki-148. Thus, I think it would be proper to add it to the game.

Its primary purpose would be in naval battles for long-range shots, and it could probably be overridden in combat by using the vertical guidance controls. However, if it did indeed auto-level at the horizon, then the usefulness of this implementation would be questionable…

That makes sense. However, if they add it to the game, the use in ground battles will be very difficult. In real life this is of course only an anti-ship missile, but GJ has marketed it more as an anti-tank weapon, probably because naval is not popular.

I have no objection to making the missile more realistic, but this is a reason it may be unlikely for GJ to implement it in terms of gameplay.

Aside from this, although I don’t have contrary evidence, I am somewhat skeptical of the explosive mass of Ki-148 in the game. Out of the 300kg shaped charge, in-game only 130kg, or 43%, is explosive mass. Does anyone know if this is reasonable for a shaped charge? For example, the massive shaped charge developed for Ki-167 (Sakura-dan) had an explosive mass of about 70% the warhead weight, although this is radically different in scale.

I am not able to find a source which can detail the explosive vs. inert mass of Ki-148’s warhead, so I’m assuming that GJ simply guessed an amount.

The filling rate of 43% is close to the value of the Army Type 92 250kg bomb.

The hollow charge warhead for torpedoes developed by the Japanese Navy has a charge rate of 58%.

The explosive type may not have been Shimose explosives (picric acid), but rather RDX 50%+TNT 50%, typically used in Japanese Army hollow charge shells and bombs.

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