- Yes
- No
Development
In 2000, the Kawasaki OH-1 (nicknamed the Ninja) entered service. It is Japan’s first indigenously designed and produced helicopter, having replaced the Hughes OH-6 Cayuse. It is a remarkable culmination of several advanced technologies, such as the all-composite bearingless and hingeless main rotor system. Kawasaki pioneered a new manufacturing process called Matched-die Isostatic Pressing to make this possible. In addition, Fuji Heavy Industries (now Subaru Corporation) and Mitsubishi Heavy Industries cooperated in its development, the latter of which contributed the Mitsubishi TS1-M-10 turboshaft engine. Remarkably, its development was on schedule, concluding without a single accident. But even before the Ninja entered service, the JGSDF had been studying the possibility of upgrading the helicopter into an attack variant. As such, the OH-1 was intentionally designed with the additional capacity required to fulfill this requirement, allowing for relative ease of modification. Thus, it can be said that the plans to up-arm the OH-1 have always been concrete.
The possibility of seeing this attack variant, the AH-2, arose with the process to replace the AH-1S Cobra, as part of the AH-X program. In 2005, the Japanese MoD ordered 60 AH-64D Apache Longbows, to be built under license by Fuji Heavy Industries, under the designation “AH-64DJP”, with the first helicopter delivered to the JGSDF in 2006. However, delivery would soon come to a standstill with only 13 helicopters being procured, with rising costs an issue, further complicated by Boeing ceasing Block II production in 2007. Thus, the JGSDF revamped the AH-X program to introduce a new design that would allow the helicopter gap to be filled. While the Ministry of Defense (MoD) itself did not officially reveal candidates, what is known is that Boeing proposed the AH-64E Apache Guardian and that Kawasaki proposed a heavily armed version of the OH-1, the AH-2. The AH-2 was seemingly the most favored design. In the end, however, the MoD ended up choosing neither of the proposals, with the AH-1S still providing the bulk of the attack helicopter fleet today.
So, is the AH-2 a mere paper design? For a while, it was thought so, especially given the lack of details and veritable information. The AH-2 project remains closely guarded. However, it has recently come to light that the proposal was farther along than previously thought.
Capabilities
While the OH-1 had originally been designed to accommodate any future modifications, including those regarding combat, its original purpose as a reconnaissance helicopter led to the prioritization of weight reduction. Thus, it would be necessary to give the OH-1 a stronger engine and transmission to handle any increase in weight due to armament. As part of a research program to upgrade the OH-1’s TS1 engine, Mitsubishi would accordingly develop the XTS-2 starting in 2006, finishing in early 2011. This would be the powerplant around which the AH-2 would be made possible.
XTS-2 Development
These are translated. The original Japanese specifications are included in the “Additional Media” and “Sources” section below
The XTS2 powerplant is the culmination of research that began with the OH-1’s TS1-M-10, capping off years of follow-up studies that examined its shortcomings. Mitsubishi sought not only to increase the engine’s power but also to improve its environmental resistance (such as guarding against foreign objects), fuel consumption, responsiveness, reliability, and maintainability. You can see below how it includes features such as the Inlet Particle Separator (IPS) and even an Infrared Reduction System (IRS). Interestingly, while the XTS2’s output turbine shares the same basic structure as the TS1 to reduce cost and weight, it also manages to cool the turbine heat shield assembly by utilizing secondary air from the compressor and expells the hot gas from the main stream of the gas turbine without using any special components. The XTS2 was subjected to the Preliminary Flight Rating Test (PFRT) at the Technical Research Headquarters of the Ministry of Defense, as seen in the bottommost row of images. Truly, it can be said that the XTS2 is a captivating marvel of engineering. For those interested, I have attached the development history in the “Sources” section.
The transmission would be upgraded as well, for a rating of 1600 hp. Furthermore, Kawasaki planned to alter the body of the OH-1, extending its rotor blades, tail section, stub wings, and further improving the armor and strength of the forward fuselage. However, other features of the OH-1, such as the integrated cockpit, would remain the same, nodding to the fact that it truly was designed to be easily modifiable.
As for the armament, the AH-2 would be fitted with the three-barreled 20 mm M197 electric cannon, the same one fitted to the AH-1S. It would also have the provision to fire Hydra 70 unguided air-to-ground rockets and the phenomenal Type 96 multi-purpose missile system (MPMS).
About the MPMS
Many of the capabilities of the MPMS are shrouded in secrecy, due to it still being in service. What is known is that it is uses an infrared seeker coupled with an optical fiber connection to ensure high accuracy. After it’s fired, the missile detects targets, of which the operator designates one to be struck, utilizing man-in-the-loop guidance. Thus, the operator is capable of issuing updates from outside the line of sight, due to the TV image sent through optical cable, much like the Spike LR. A tank’s roof can be precisely targeted, as the missile follows the course instructions. As the MPMS was also designed to take out landing craft, it has a warhead that Japanese officers consider to be overkill for a tank and is also said to be able to penetrate composite armor.
In the video below, you can see how the missile hits the target from a steep angle after climbing. Such an attack would not only bypass the most protected areas of a tank but potentially APS as well.
These details emerged in the January 2022 issue of the Journal of Defense Technology, covering the development of the AH-2. While I sadly do not have access to the journal, some pages have emerged online. Below is a translated section.
The blue text boxes, as the key suggests, are components directly sourced from the OH-1 with little to no changes. The green text boxes, confusing translated as “gross up”, are components sourced from the OH-1 that have been upgraded, such as the transmission, engine, recoil compensation to the fuselage nose, etc. The yellow text boxes detail brand-new equipment added to the base OH-1 to yield the AH-2, such as the aforementioned MPMS, in addition to the HMD, datalink, etc. Considering that the vast majority of the AH-2 are components sourced directly from the OH-1, or are upgraded components, it underlines the flexibility of the original design and the anticipation that it could one day become an attack helicopter.
Additional Development Details
Below is the proposed schedule put forth by Kawasaki in developing the AH-2. Sections H9-H11 show that Kawasaki conducted internal research on the AH-2, while sections X+1-X+7 are the proposed timeline for mass production. Unfortunately, due to the tight-lipped nature of the MoD, we do not know where exactly the AH-2 stands in its development. I have included the original Japanese page in “Additional Media” below.
Some of the research conducted confirmed that there would be no problems with adding the 20 mm gun.
In War Thunder
It should be reiterated that the AH-2 is not a paper vehicle, and as an unfinished prototype, it has a place in War Thunder in Japan’s very sparse helicopter tree. As the AH-2 is a derivative of the OH-1, several components remain the same, as seen in the diagram above: the ducted tail rotor, integrated cockpit, and hingeless rotor system-pointing to a more grounded, rather than fantasy, design. However, arguably the most important part of the helicopter, the XTS-2 powerplant, was prototyped and tested. It is a unique powerplant tied to the OH-1, as the shortcomings of the TS1-M-10 directly informed its development. It cannot be thought of as a separate, parallel development. It is not an off-the-shelf design, as it never reached mass production for use in other helicopters like the AH-64. The AH-2 is not some “what-if” assembly of preexisting parts. Lastly, for those more concerned about weaponry, the proposed armament of the AH-2 are all currently in service with the Japan Ground Self-Defense Force, meaning that they have real-world data that can be used.
Currently, the Japanese helicopter tree is in a sad state, having only four TT vehicles and one premium. While this of course reflects the reality of the JGSDF, it leaves much to desire for gameplay. A possible addition like the UH-2 can only bring unguided rockets, while the Mitsubishi SH-60 brings at best 4x Hellfires to ground battles. Unique Thai possibilities, such as the Boeing AH-6 and Eurocopter Fennec, have very small loadouts, although they are interesting airframes. Additionally, with news revealing that ASEAN vehicles may go to China, the future of the Japanese helicopter tree isn’t looking too bright. Thus, it is necessary for Gaijin to be more flexible in adopting this unfinished prototype (as it should for all trees, to avoid copypaste). The AH-2 is the perfect solution as it boasts a competitive loadout that would allow it to fight at top tier, thanks to its MPMS missiles and Type 91 Kai AAMs. It would add much-needed variety to the tree, serving alongside the AH-64DJP, which has some weaknesses. For example, the lack of a missile approach warning system (MAW) on the DJP leaves it vulnerable to the plethora of SAMs and AAMs at its BR. While it is unknown if the AH-2 has MAW, its MPMS missiles would allow it to safely attack enemy armor via man-in-the-loop guidance. Additionally, the ATAS (AIM-92) missiles can be lacklustre, compared to the more promising Type 91 Kai which has smokeless propellant and improved tracking. In the end, the AH-2 is a much-needed ray of hope for the Japanese helicopter tree, managing to be a competitive airframe that avoids the copy-paste cliche.
Thank you for reading!
- 11.3
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- I don’t want it :(
- TT
- Squadron
- I don’t want it :(
Kawasaki AH-2 Specifications
- Guns: 20 mm M197 electric cannon
- Rockets: Hydra 70
- Missiles: Type 91 Kai air-to-air missiles (SAM-2B), Type 96 multi-purpose missile system (MPMS, ATM-4)
- Hardpoints: 4× hardpoints under stub wings
- Dimensions: ~13.2 m length, ~3.8 m height, 12.4 m main rotor diameter
- Crew: : 2 (pilot and co-pilot/gunner)
- Maximum Speed: Unknown
- Powerplant: 2x Mitsubishi XTS-2 (940 kW, 1260 hp each)
Sources
Thanks to @skultew1234 and @あの賢い男_赤城 for sourcing and translating
Kawasaki OH-1 - Wikipedia
OH-1 - Wikipedia
AH-X - Wikipedia
XOH-1 (OH-X)
(1) わいえす on X: “防技ジャーナル 2022年1月号24Pより 20mm機関砲（M197？）、MPMS8発、ハイドラ70ロケット、91PSAMと言う武装構成 https://t.co/OJZYgPSmeB” / X
XTS2 Development
Wayback Machine
Type 91 portable surface-to-air guided munition - Wikipedia, the free encyclopedia
Type 96 Multipurpose Guided Munition System - Wikipedia, the free encyclopedia
Why Japan's Type 96 Multi-Purpose Missile System Failed | Random Japan Academy