306 replies to this topic

[Lostwingman]

J311yfish, on 05 March 2014 - 02:17 PM, said:

Update:    (old ----> new)

-- added jets at Tier VIII, IX, X according to engine lineage and J7W2 precedent

-- rearranged the tree more strictly across Navy/Army lines for these reasons:

• to make jet relationship more apparent
• to resolve the muddy overlap of heavy fighter / ground-attack roles
• to indicate the Nakajima IJA line as the major parallel track from which smaller specializations can be made.
• The new structure also makes it easier to incorporate other aircraft (if more are needed) based on their armament lineage, particularly at lower tiers.

 

 

Where did you get a Ki-201 Kai from? They only got as far as making an enlarged Me 262 for production to start around December '45.

The Kitsuka was started earlier and saw much more work around around it including variations.

 

[J311yfish]

lostwingman, on 06 March 2014 - 06:21 PM, said:

Where did you get a Ki-201 Kai from? They only got as far as making an enlarged Me 262 for production to start around December '45.

The Kitsuka was started earlier and saw much more work around around it including variations.

 

"Ki-201 Kai" is a placeholder name for the logical extension of the Ki-201, with "kai" simply meaning improved.  I took a similar liberty with "R2Y3," following the J7W3 precedent established by developers, in order to fill Tier X in a reasonable manner.  See quote below (or post above) for how that makes sense with respect to the engines.

 

J311yfish, on 05 March 2014 - 12:56 AM, said:

If this article is accurate, then there are 5 avenues for Japanese jet engine design:

 

1) turbojets inspired by German design -- leading to the Ne-10, Ne-12, Ne-120, Ne-130, Ne-230, Ne-330 engines (Kyushu J7W, Nakajima Kitsuka, Yokosuka R2Y2, Kawanishi K-200)

2) Campini-type jet engines inspired by Italian design -- leading to the Ishikawajima Tsu-11 engine (Yokosuka MXY9)

3) Bi-fuel rocket engines inspired by German design (Me-163) -- (Mitsubishi J8M)

4) pulse jet engines inspired by German (V1 flying bomb, He-162 Volksjager) -- leading to Maru KA 10 engine (Kawanishi Baika)

5) Pescara-type free piston compressor design -- no information

 

The most promising avenue with respect to Tier IX and Tier X for this game appears to be the turbojets, obviously.  So considering what is in game now:

 

Tier IX:  J7W2 -- Ne-130, Ne-230, Ne-330

Tier X:  J7W3 -- Ne-440

 

And looking at where engines in that line of development were used (or planned):

 

Nakajima Kitsuka -- Ne-10, Ne-12, Ne-120 (x2)

Nakajima Ki-201 -- Ne-130, Ne-230 (x2)

Yokosuka R2Y2 -- Ne-330 (x2)

 

A reasonable proposal would be:

 

Tier VIII: J7W1 // Nakajima Kitsuka

Tier XI:   J7W2 // Nakajima Ki-201 // Yokosuka R2Y2

Tier X:    J7W3 // Nakajima Ki-201 KAI // Yokosuka R2Y3

 

That would give fighter, fighter-bomber, and attack aircraft at Tier IX and X, and basically complete the upper end of the Japanese tech tree.

[Lostwingman]

I have Edwin Dyer's book on my kindle right here. All those engines were considered for the Kitsuka which was much different from the Me 262 and especially the Ki-201. Additionally, the Ne-10 and Ne-12 were developed in 1943, how could they possibly be influenced by German information that did not reach Japan until Summer 1944? The Ne-20, Ne-130, Ne-230, and Ne-330 were the designs immediately inspired by the axial compressor drawing (each one designed by a different group). Ne-120 as far as I can find does not exist. The Ki-201 was the lesser modified design between the Kitsuka and 201, the Kitsuka had several variants. For our purposes is the original shimpu craft with dual 20mm cannons, an interceptor from that using a single 30mm cannon, and a FIghter-Bomber variant that would be slightly heavier and use either the 130 or 330 and two 30mm. Additionally, I have no idea where WG got the Ne-440, I think it is an invention on their part.

 

On the R2Y, it seems capable of receiving J7W treatment:

Block Quote

Even before the destruction of the first R2Y1, a second was being constructed and design work for the R2Y2 was underway. Contemporary sources show no less than four versions for how the R2Y2 may ultimately have appeared. The first had the Ne 330 engines in underwing nacelles. The second version showed the two engines buried within the fuselage with wing root air intakes and narrow jet nozzles. The third removed the wing intakes and replaced them with a nose intake, but it retained the narrow nozzles. Finally, the fourth was similar to the third save that the engine nozzles were larger. The first design is considered by most to be the initial R2Y2 concept while the other three are subject to debate. In part, this is due to the fact that the Japanese had very little time to explore various installations of turbojets in airframes.

Dyer, Edwin  M (2009-11-05). Japanese Secret Projects: Experimental Aircraft of the IJA and IJN 1939-1945 (Kindle Locations 3725-3731). Midland Pub Ltd. Kindle Edition.

 

Only questionable issue is that there is little info on armament.

 

I would contend this starting at tier 8, have the Ne-20 powered Kitsuka, have it lead to the Ki-201 and the more definitive Kitsuka design using the 330s. Definitive Kitsuka can lead to the tier X R2Y concept with other R2Y concepts directly bellow it, making the two Kitsuka's at tier 8 & 9 form a short parallel branch like you have with the IL-8 and IL-10 on the Soviet tree.

Tajikawa Ki-94-I is pretty interesting, 781km/h and as many guns as necessary to confuse it with a Sturmovich. It's only problem is it is a push-pull propeller craft. Still, seems Tajikawa had a bunch of wacky designs we could funnel the Ki-201 over into.

 

Edited by lostwingman, 06 March 2014 - 08:40 PM.

[J311yfish]

I appreciate your detail.  The "inspired by German design" phrase was mine and you are absolutely right to call me out on that hasty generalization.  

 

I do regret relying on Wikipedia for most of my information (the Ne-120 reference is from here).  I have checked out the Francillon (1970, 1979, 1987) and Dyer (2009) books from the library and will review them closely tonight.  I think I see what you are saying about the Ne-330 arrangement and the parallel treatment similar to Soviet tree.

 

I will be using the Francillon/Dyer books to confirm all information, and put it into a spreadsheet so that it is easier to keep track of; then I'll upload it so all have access.

 

I have not found any evidence to support the existence of Ne-440 either (or J7W3 for that matter); that is the only reason I felt comfortable moving forward in a logical manner to Tier X.  I'm not completely comfortable doing that but if there is a historical premise and if WG has decided it is reasonable to do it, then I'd be glad to investigate.

 

 

 

 

[Lostwingman]

Past the J7W they appear to be based on design inclinations Dyer mentions:

Block Quote

The end of the war also spelled the end of the J7W2 Shinden-Kai. This was to be the turbojet- equipped version of the Shinden. The use of the radial engine had been a stop gap until a suitable turbojet was available. The Ne 12B was rejected as its power was considered too low to effectively propel the aircraft. In any case, work was by this time under way on the K ūgishō Ne 20 turbojet that was based on the German BMW 003A engine, the only turbojet built and flown in a Japanese aircraft: the Nakajima Kitsuka ( page 114 ). The J7W2 was to use the Ne 130 turbojet, also based on the BMW 003A, which was being developed by Ishikawajima-Shibaura. The Ne 130 was to have produced nearly double the thrust of the Ne 20; however, the Ne 130 would not be ready by the close of the war and as such the J7W2 remained a design board aircraft . There is speculation concerning what the J7W2 would have looked like. One suggestion is that the J7W2 would have been the J7W1 with the Mitsubishi radial replaced with the Ne 130 turbojet . A second suggestion concerns the fact that without the need for propeller clearance the Shinden could dispense with the tall landing gear, thus lowering the height of the aircraft. Aside from modifying the landing gear, the vertical stabilisers, fuselage and canopy shape may also have required adjustment. It is likely that had development of the J7W2 commenced with the availability of the Ne 130, a J7W1 airframe would have been adapted to accept the engine and testing conducted on this, with other modifications coming into play as a production J7W2 was standardised.

Dyer, Edwin  M (2009-11-05). Japanese Secret Projects: Experimental Aircraft of the IJA and IJN 1939-1945 (Kindle Locations 4126-4138). Midland Pub Ltd. Kindle Edition.

 He also has some art in that book predating WoWP that match the J7W2. The J7W3 is probably just a "what if bubble canopy for better visibility?" and "assume biggah engine!".

[J311yfish]

Regarding Yokosuka R2Y2 armament:

 

Francillon writes as early as 1970:

"In late 1944 the design staff of Dai-Ichi Kaigun Koku Gijitsusho suggested that the R2Y2 be redesigned as a jet attack bomber.  For this purpose it was intended to replace the fuselage-mounted Aichi [Ha-70] 10 (twin-coupled Atsuta 30 engines) with a large-capacity fuel tank, and to attach a 1,320 kg (2,910 lb) thrust Ne-330 turbojet under each wing outboard of the main undercarriage units.  Armament was to consist of a single 800 kg (1,764 lb) bomb slung beneath the fuselage and a battery of cannon installed in the nose.  Maximum anticipated speed at sea level was 430 kt (495 mph) compared with 388 kt at 10,000m (447 mph at 32,810 ft) for the piston-engined version.  This proposal was enthusiastically received by the Navy who, while detailed engineering design of the jet-powered R2Y2 was actively pursued, gave their authorization to complete the piston-engined R2Y1 as an aerodynamic prototype for the jet attack aircraft."

 

"Completed in April 1945, the R2Y1 prototype was transferred to Kisarazu where taxi-ing tests were marred by nosewheel shimmy and difficulties with an overheating engine.  Finally on 8 May the aircraft made its first flight with Lieut-Cdr Kitajima at the controls.  Unfortunately this flight had to be cut short because there was an abnormal rise in oil temperature, while a few days later an engine fire on the ground necessitated a complete engine change.  Before this could be done, the R2Y1 was destroyed by American bombs."

 

"At the end of the war a second R2Y1 prototype was under construction, and design of the R2Y2 had almost been completed." (p.473-474)

 

Dyer has more to say in 2009 about the R2Y1 and R2Y2 development, but his conclusion about armament is the same:

 

Dyer writes in 2009:

"For weapons, the aircraft would carry one 800 kg (1,764 lb) bomb and have a cannon armament in the nose."

 

"Unfortunately for Kugisho and the IJN, the R2Y2 would never be brought to full production.  With the end of the war, the second R2Y1 prototype remained incomplete and the R2Y2 would forever remain a design board aircraft. (p.79)

 

 

[Commander_Rasseru]

So the Yokosuka R2Y going to be the end tree of Heavies or Attack/Bombers?
So if I understand this right? It going to be R2Y VIII, R2Y1 IX, and R2Y2 X for a end tree? Or two version would be in one tree and the other version be another tree because it designed for a different role?

[Lostwingman]

It actually has a pretty good shot of being a light fighter given it's only got one engine and is supposed to be pretty light.

 

Whelp I'm a moron, forgot it was two engines staggered in the fuselage...

Edited by lostwingman, 07 March 2014 - 05:34 PM.

[J311yfish]

I have looked closely at the timelines for each of the above aircraft (as noted by Dyer below), and these are the facts that become apparent:

 

• J7W1 was designed first, Kitsuka second, R2Y2 third, Ki-201 fourth, even though they were all parallel projects.
• J7W1/2 production was to be the most ambitious (150/month), then Kitsuka (530 to be built in about 10 months), then Ki-201 (18 by March 1946), and R2Y2 production does not appear to have been established (2 prototypes).
• Data for the Ne-230 and Ne-330 were anticipated, but not confirmed, at the time of surrender 15 August 1945 (Ne-230 three under construction but zero completed; Ne-330 zero completed)

 

As the airframes were under development they had these engines in mind:

 

• J7W2:  Ne-130 (x1)
• Kitsuka: Ne-12, Ne-20, Ne-130, Ne-330 (x2) -- though it should be noted that the Ne-12 and Ne-20 were in competition with each other for use due to time constraints
• Ki-201: Ne-230, Ne-130 (x2) -- it should be noted here that the Ne-130 was considered an upgrade to Ne-230 because it produced higher thrust (though it also weighed more)
• R2Y2:  Ne-330 (x2)

 

Engine comparison:

 

• Ne-20       490 kg (1080 lb) of thrust
• Ne-130     900 kg (1984 lb) of thrust
• Ne-230     885 kg (1951 lb) of thrust -- anticipated, but not known at the time of surrender
• Ne-330    1300 kg (2866 lb) of thrust -- anticipated, but not known at the time of surrender

 

So given the details above it was a good decision to bring J7W2 into the game as the first Japanese jet.  It is important to establish that if the J7W is going to be used as a precedent for the others.  It is also apparent that Kitsuka would be a good second choice.

 

 

Now, based on the best information available (Dyer and his extensive bibliography), following historical precedent, and using current J7W engines as guideline for tier placement:

 

VIII: Kitsuka (Ne-20 x2)

IX:   Kitsuka (Ne-130, Ne-230, Ne-330 x2) ----- Ki-201 (Ne-130, Ne-230 x2) ----- R2Y2 (Ne-330 x2)

X:   To be determined

 

Tier X is a logical leap that involves using the fictional Ne-440's.  It could mean a faster Kitsuka, "Ki-201 Kai"or "R2Y3" but I don't want to diminish the integrity of the rest of the tree by embracing fiction here at the end, so I will fix the tree to indicate that.

 

Timelines extracted from Dyer text:

 

J7W timeline

__ ___ 1943    need identified for a new interceptor
__ ___ 194_    glider testing to prove canard concept
__ May 1944    J7W1 ordered into production
__ June 1944    1st prototype production begins
__ Sep 1944    wind tunnel testing
__ Sep 1944    production plans formulated; Kyushu planned 30/month, Nakajima planned 120/month
__ May 1945    nearly complete
__ Jun 1945    1st prototype complete without armament; weighted in nose to simulate armament
03 July 1945    1st prototype flight attempt; swerved off runway; damage to prop and stabilizer = 1 month delay.
03 Aug 1945    prepared for 2nd flight
06 Aug 1945    2nd flight
08 Aug 1945    3rd and final flight
15 Aug 1945    Surrender.  J7W2 Shinden-Kai remained in design status; was to use the Ne-130.

 

 

Kitsuka Timeline:

16 April 1944    I-29 submarine leaves Lorient, France with Me262 plans, BMW 003 turbojet, Junkers Jumo 004 turbojet.
14 July 1944    Technical Commander Eiichi Iwaya disembarks from submarine in Singapore
26 July 1944    I-29 submarine sunk near Balintang Channel in Luzon Strait
_____ 1944    Technical Commander Eiichi Iwaya arrives in Japan with single copy of BMW 003A cross-Section.
__ Aug 1944    Conference to discuss changes in air strategy; 3 classes of aircraft proposed (origin of Kitsuka).
14 Sep 1944    IJN representatives meet with Nakajima; Kitsuka design confirmed
08 Oct 1944    Nakajima plant director orders wooden mock-up to be completed by the end of the month; not completed until end of January.
09 Dec 1944    IJN calls meeting to check status of Kitsuka project
03 Jan 1945    Debate about using Ne-20 or Ne-12; consensus says Ne-12 likely ready sooner.
05 Jan 1945    Japanese troops pushed out of Burma
06 Jan 1945    B-29’s bombing Tokyo
28 Jan 1945    Kitsuka wooden mock-up ready for inspection; Nakajima instructed to end J5N1 and G8N1 projects to focus on Kitsuka.
31 Jan 1945    Ne-20 final design completed
__ Feb 1945    Japanese docks in Singapore destroyed by American B-29’s; continued fighting in Philippines .
10 Feb 1945    2nd inspection of Kitsuka; final approval and production ordered despite no test flights
__ Feb 1945    Ne-12B tested for the first time
17 Feb 1945    Kitsuka engineering staff moved to another facility to avoid expected bombing raids; sizable portion of component construction remained behind.
__ Mar 1945    U.S. incendiary bomb campaign ramped up
26 Mar 1945    Ne-20 successful test in a cliff-side cave in Yokosuka; outperformed Ne-12B; decision made to delay Kitsuka to refit it for Ne-20.
31 Ma 1945    Kitsuka revisions complete
25 Apr 1945    1st Kitsuka fuselage complete
20 May 1945    stress/load testing
13 Jun 1945    Vice Admiral Wada holds meeting to discuss Kitsuka; aluminum stock expected to be exhausted by the end of 1945; only steel and wood, which would necessitate another revision to Kitsuka design.  High grade fuels to be used for Homare radial engines; Ne-20 would have to use fuel of poorer quality.
25 Jun 1945    1st Kitsuka completed without engines.
27 Jun 1945    Kitsuka reassembled at new location to meet Ne-20 engines.
29 Jun 1945    weight/balance checks completed; ready for flight testing; disassembled again and relocated to airfield for testing at Kisarazu Air Base adjacent to Tokyo Bay.
14 July 1945    engine damage during testing, replacement the only option
15 July 1945    Kitsuka pilots assemble at Misawa Air Base for training.
27 July 1945    successful taxi test
06 Aug 1945    ground testing completed – same day Hiroshima devastated by atomic bomb
07 Aug 1945    Kitsuka 1st flight; total flight time 11 minutes; post-flight inspection passed.
11 Aug 1945    Kitsuka 2nd flight; RATO units complicated takeoff; ran off runway and 100m of grass into drainage ditch; extensive damage to Ne-20’s; recorded with motion picture camera.
15 Aug 1945    film studied, but inconclusive.  Imperial Rescript on the Termination of the War.

 

 

Ki-201 timeline

__ Oct 1944    Japanese embassy informs Germans that IJA would produce Me262; requested reports and projections for production of 100-500/month.
12 Jan 1945    Nakajima design team formed; goal to build jet fighter resembling Me 262 as close as possible.
__ Jun 1945    wind tunnel testing completed
15 Aug 1945    1st fuselage almost complete.  Imperial Rescript on the Termination of the War.

 

 

R2Y timeline

__ ___ 1942    need identified for a reconnaissance aircraft fast enough to avoid interception Y-30 and Y-40 projects intiated; Y-40 inspired by He119; Y-40 became the R2Y1
__ Fall 1944    long range reconnaissance role no longer needed; need for fighters/bombers instead
__ late 1944    proposed adaptation of R2Y1 airframe to accommodate Ne-330 engines for fast attack bomber role; Ne-330’s to be slung under the wings in nacelles; designated R2Y2.  R2Y1             airframe to be used to demonstrate handling characteristics.
__ Apr 1945    1st R2Y1 prototype completed.
08 May 1945    1st R2Y1 flight; cooling issues; engine damage; repairs necessary
__ May 1945    1st R2Y1 prototype destroyed by U.S. bombing raid; 2nd R2Y1 prototype still under construction; R2Y2 still in design phase.
15 Aug 1945    2nd R2Y1 still incomplete; R2Y2 never built.  Surrender.

 

 

Engine timeline

16 April 1944    I-29 submarine leaves Lorient, France with Me262 plans, BMW 003 turbojet, Junkers Jumo 004 turbojet.
14 July 1944    Technical Commander Eiichi Iwaya disembarks from submarine in Singapore
26 July 1944    I-29 submarine sunk near Balintang Channel in Luzon Strait
_____ 1944    Technical Commander Eiichi Iwaya arrives in Japan with single copy of BMW 003A cross-section.
__ late 1944    proposed adaptation of R2Y1 airframe to accommodate Ne-330 engines for fast attack bomber role; Ne-330’s to be slung under the wings in nacelles; designated R2Y2.  
03 Jan 1945    Debate about using Ne-20 or Ne-12 for Kitsuka; consensus says Ne-12 likely ready sooner.
31 Jan 1945    Ne-20 final design completed
__ Feb 1945    Ne-12B tested for the first time
26 Mar 1945    Ne-20 successful test in a cliff-side cave in Yokosuka; outperformed Ne-12B; decision made to delay Kitsuka to refit it for Ne-20.
__ May 1945    Nakajima Ne-230 development started
__ Jun 1945    Ishikawajima Ne-130 completed, but untested
__ Aug 1945    Nakajima Ne-230 – three under construction
15 Aug 1945    Mitsubishi Ne-330 – zero constructed; remained on design board.  Surrender.

 

 

[Lostwingman]

Unless there is information out there Dyer is not aware of the design of the J7W3 appears to be a WG creation.

 

And this is my 666th post. I feel accomplished and truly frightening.

May my days of failing at vidya gaems continue ever more.

Edited by lostwingman, 07 March 2014 - 04:35 PM.

[Commander_Rasseru]

What if the A6Ms and the J7Ws are merged together in the future? If it is partly and fully..... What aircraft would be the best to fill in for the missing tiers? 
Like the A6M1 and A6M2 merged to be Tier V. What would be the new tier IV? This is just a example.

[Lostwingman]

Unless you have something between the A5M and the A6M they won't do it.

[J311yfish]

Still working on the tech tree after reviewing Francillon and Dyer closely, and I have learned a few things.

 

The current tech tree is a reasonable "rough draft" but the problems with it that I see are:

 

1.  Emphasis is on what is possible rather than on what is probable.  

The goal here should be to identify what is likely to be the clearest (most obvious) path forward without getting mired in possibilities (there are many).  Upon closer review it is clear that I made some hasty judgments with respect to available prototypes or projects in order to fill-in certain tiers.  Rather than make the smaller judgments myself, I will instead account for them as variables; that way whoever follows this work can make their own decisions without doing extensive research or wondering about my thought process.  

 

The main IJA fighter line still remains fairly obvious based on production values, sequential development, speeds, armaments:

 

 

2. Ground Attack / Heavy Fighter issues.

The "ground attack" role is not concentrated in an obvious aircraft lineage as it is with the Russian IL's; the role is instead dispersed among bombers, dive bombers, torpedo bombers, fighter-bombers, etc.  However, there are cases where an existing aircraft is adapted to the role (Ki-45, Ki-46, Ki-102) or designed for it (Ki-93, Ki-98 before changing to high-altitude concept).  I have identified what I consider to be the "ground attack" line based on speeds, armaments, and extensive comparison to attack aircraft and heavy fighters currently in the game.  If employed it would provide a ground attack experience that is characterized by slightly greater speed and maneuverability at the expense of armor.  I will edit this post later with images/comparisons to show how that would work (done, see below).

 

The problem is with the "heavy fighter" concept, which remains muddy despite my best efforts due to the abundance of choices and the challenge of IJA/IJN overlap. I have therefore accounted for them as variables and I will probably not venture further into that entanglement unless someone more knowledgeable than myself can shed light on the issue.  There are some great/interesting planes there and I don't want to be exclusive.  Also, there is still the question of schrage musik and other variations (whether they have relevance in game without bombers or night time, how it could be aimed or would it function automatically like a rear turret, etc.) and I don't want to speculate about that.

 

So with these things in mind, here is a more polished revision.  Still a work in progress but getting closer I think:

 

I have removed Ki-100, Ki-116, and Ki-96 from the big picture only because they are airframe progressions for Ki-61, Ki-84, Ki-102.  A detailed tech tree (one that shows all airframe, engine, armament progression) should include them.

 

I have a few more notes about this but I'll have to add them later.

 

Ground Attack / Heavy Fighter roles in depth:

All of this information has been taken from the World of Warplanes Encyclopedia (after the 1.2 update).  It has been arranged in a horizontal manner in order to make comparisons easy.  Ground attack aircraft in game have a brown background, IJN aircraft are in blue, IJA are in green.  Sources for Japanese aircraft are Francillon, Dyer, and Wikipedia if necessary.

 

Tier II:

 

Tier III:

 

 

Tier IV:

 

Tier V:

 

Tier VI:

 

Tier VII:

 

Tier VIII:

 

Here is a close-up evaluation of IL-20 vs. Ki-93 -- both heavily armored with comparable weaponry:

 

If this pairing is valid, it would suggest that the Ki-93 would be faster and more maneuverable than the IL-20 at the expense of armor and bomb/rocket payload.

 

 

[J311yfish]

Double-boom fighters have a high fun factor.  I was curious to discover if the J4M in earlier versions of the game might be reincarnated as the Ki-98 or Ki-94-I to fill potential holes in the tech tree.  If so, it would not occur without alterations to the J4M model:

 

Double-boom fighter comparison:

 

 

The information in gray is dubious given that all were in prototype status and expected to use the same engine.

 

 

Tachikawa Ki-94-I

• three-view drawing here
• pictures of the original mock-up here
• story about the designer here
• video of RC model here

[Lostwingman]

All that Dakka...

 

I'm not sure that's such a stretch for tier X.

 

I'm serious though, trade a little bit of hit points/survivability for the speed and a 57mm/2x20mm @ tier 9 and a 75mm anti-shipping plane @ tier X seems downright reasonable for an Attack Aircraft line.

 

Especially when you consider the A2D Skyshark is going to be pretty high on an eventual American line (legit end game potential).

Edited by lostwingman, 10 March 2014 - 04:29 PM.

[J311yfish]

Fuzzybrainlizard, on 24 February 2014 - 08:25 PM, said:

Another interesting Japanese experimental fighter was the Kayaba "Katsuodori" Ku-4 Ram Jet fighter.  Premium? 

https://hangar47.com/uploads/Katsuodori-6.jpg

 

I have been reading more about the Kayaba Katsuodori Ku-4 ram jet fighter.  There is not much information to be found (Wikipedia or otherwise), but Dyer has good details:

 

 

Kayaba Katsuodori Ku-4

Type:  Point Interceptor

Crew: 1

Speed:  900 km/h estimated* (see Speed-Thrust table below)

Climb rate:  3min to 10,000m

Ceiling:  15,000m

Range: 400km

Endurance: 30min

Armament:  2x30mm caseless ammo

Span:  8.99m

Length: 4.48m

Height:  1.85m

Wing area: 12.57m²

Wing sweep: 25.5 degrees

Empty:  850kg

Loaded: 3000kg (caseless ammo helps) (1500kg of fuel consumed 50 kg/min)

 

The ram jet was to be brought to speed initially through the use of 4 rocket boosters (7200 kg thrust combined, then released to minimize drag, shown in picture above) and a wheeled apparatus (no landing gear).  After passing 367 km/h approx the ram jet would begin to function efficiently.  Dropping below that speed (approx) would mean that the ram jet would be unable to provide enough thrust to sustain forward movement, making you essentially a  vulnerable glider.

 

Maneuverability:

-- no tail + vertical wingtip rudders = very high roll rate?

-- variable speed/thrust relationship as mentioned below

-- Ku-4 was to have a rear-mounted 120hp de Havilland Gipsy 4-cylinder air-cooled inline engine w/ two-bladed propeller (130kg?); enough to maneuver as a glider, not enough to maintain speed.

 

Three-view:

 

Artist:  Peter Allen.  Source:  Edwin Dyer's "Japanese Secret Projects" Book 1.

 

The 4 rocket boosters are thought to be released after they are expended during takeoff.

 

 

Speed-Thrust relationship:

 

367 km/h -- 300 kgf

490 km/h -- 420 kgf

612 km/h -- 550 kgf

734 km/h -- 750 kgf

1103 km/h -- 750 kgf

 

(i.e. no increase in thrust generated beyond 734 km/h)

 

 

Timeline:

 

1908 ramjet patented by French engineer Rene Lorin

1933 ramjet built and tested by Russian engineer I. A. Merkulov (GIRD-04)

1937 Kayaba Ramjet Study Group begin to investigate ram jets

1937 Kumazo Hino inspired to create tailless glider

1938 February -- HK-1 tailless glider completed

1938 December -- ground towing tests

1939 September -- air-release tests; IJA is interested

1940 April -- HK-1 prototype crashes after 182 flights; IJA still interested

1941 May -- Ku-2 prototype crashes after 270 flights

1941 -- Ku-3 prototype crashes after 65 flights

1943 -- Ku-4 design nearly complete; IJA withdraws funding to focus on the rocket-powered Ki-200; Ku-4 remains unfinished.

 

Also of note is that the designer, Kayaba, offered to adapt the idea to use the Ne-20 turbojet (490 kg thrust, planned for Nakajima Kitsuka) or KR10 rocket motor (planned for Ki-200).

 

 

Would the ram jet mechanics make it difficult to implement?  If yes, would the use of Ne-20 (as Kayaba later proposed) circumvent that?  I don't know; but it does look fun.

 

Advantages:

-- small target

-- high roll rate?

-- unusual mechanics

 

Disadvantages:

-- must keep speed high to keep engine going

-- no mention of armor or self-sealing fuel tank (1500 kg of fuel)

-- unusual mechanics

 

[Raindrops]

lostwingman, on 10 March 2014 - 04:30 PM, said:

I'm serious though, trade a little bit of hit points/survivability for the speed and a 57mm/2x20mm @ tier 9 and a 75mm anti-shipping plane @ tier X seems downright reasonable for an Attack Aircraft line.

 

Especially when you consider the A2D Skyshark is going to be pretty high on an eventual American line (legit end game potential).

I personally placed the A2D as a tier nine, but it's a bit hard to compare a plane relying on 7000lbs of bombs with one that mounts a 57mm derp. (I don't think the Ki-93 mounted bombs with that gondola either.)

[Lostwingman]

Raindrops, on 10 March 2014 - 10:47 PM, said:

I personally placed the A2D as a tier nine, but it's a bit hard to compare a plane relying on 7000lbs of bombs with one that mounts a 57mm derp. (I don't think the Ki-93 mounted bombs with that gondola either.)

Rear part of the gondola behind the 57mm/75mm.

[_Down_Range]

J311yfish, on 24 February 2014 - 11:39 AM, said:

 

The goal was to identify a chronological progression for both the Army and the Navy, as well as to acknowledge German influence (heavy fighters, jets) in order to provide avenues for advancement that are comparable to other countries.  The tech tree above represents an approach that is reasonable and modest.  Placement at each tier has been determined by careful consideration of chronological development, speed, and armament, according to the sources identified below.

 

Please keep in mind that this is just one possible (though very reasonable) interpretation -- I am not a developer or historian.

 

I am very thankful to the experts in this thread for their targeted advice and enthusiasm.

 

 

GUIDELINES -- these are the rules I followed to derive the tree:

 

There are many excellent aircraft to choose from, so these are the guidelines that I tried to adhere to:

• Priority given to chronological development with traceable lineage
• Priority given to high-production models over prototypes when possible
• Close attention given first to engine lineage, then to various armaments.
• Dive bombers omitted due to their otherwise light armament
• Rocket-powered fighters, suicide aircraft, etc. omitted because they go against precedent
• Aircraft that feature armament in specialized configurations (such as schrage musik) omitted because they go against precedent (unless there is evidence for a viable variant)
• Existing tech tree considered to be the strongest referent for tier placement (see note about speeds below)

 

 

SPEEDS -- these are the speeds used to validate tier placement:

 

The fraction in parenthesis represents the level of engine upgrade at which the speed was recorded.  For example, 1/3 indicates that the speed was measured with the first engine in a series of three made available to that aircraft (engine #1 of 3).  This is important because it provides a finer metric for tier placement.  To be fair, these values do not account for changes in weight due to armament, nor do they account for variations in optimal altitude, so there is some room for judgement.

 

Note:  This is an older version of the tree before incorporating native jet development, and before arranging more strictly along Navy/Army lines.  I will probably update it to match the current tree but for now it serves to show speeds across tiers.

 

 

ARMAMENTS -- to validate tier placement:

 

(S) = Synchronized to fire through the spinning propeller; can be mounted in the nose of the fuselage or roots of the wings

(W) = Wing-mounted

 

*** = more options not accounted for, see source.

 

Note:  The 75mm Type 88 cannon on the Ki-93 is an anti-aircraft gun but was also used effectively in an anti-tank role (source).

 

 

 

 

SOURCES -- specifications, modeling reference images, paint schemes, stories:

 

         IJA Fighters

• Kawasaki Ki-10
• Nakajima Ki-27 -- images -- specs -- many images
• Nakajima Ki-43 -- specs -- paint -- paint -- many images -- NASM
• Kawasaki Ki-61 / Kawasaki Ki-100 -- specs / specs -- paint -- many images
• Nakajima Ki-44 -- images -- specs -- paint -- paint -- many images
• Nakajima Ki-84 / Ki-106 (Ti-84 airframe variant) / Ki-116 (Ti-84 upgrade) -- specs -- paint -- many images
• Nakajima Ki-87 -- paint -- images -- 3-view
• Nakajima Ki-201

 

         IJA Heavy Fighters

• Kawasaki Ki-45 -- specs -- notes/specs -- paint -- many images -- NASM
• Kawasaki Ki-96 / Kawasaki Ki-102 -- specs -- paint -- images / images
• Rikugun Ki-93 -- images -- images
• Manshu Ki-98 -- images -- images

 

         IJN Heavy Fighters

• Nakajima J1N -- specs -- paint -- images -- NASM
• Aichi S1A 
• Nakajima Kitsuka -- images -- images -- NASM
• Yokosuka R2Y2 -- 797 km/h -- jet-powered fighter-bomber -- Ne-330 jet engines x2 -- images -- images -- another story here -- details

 

         IJN Fighters

• Kawanishi N1K -- specs -- images -- details -- paint -- images -- NASM -- NMAF
• Mitsubishi J2M -- specs -- paint -- images
• Mitsubishi J4M -- paint -- images

 

 

ALTERNATES -- may be viable but making them fit might be a challenge (see note about premiums below):

 

         High production

• Mitsubishi Ki-46 -- 604 km/h -- Ki-46-III / Ki-46-IIIb ground attack variants / Ki-46-III KAI interceptor -- specs -- images -- details
• Yokosuka P1Y -- ~547 kh/h -- heavy fighter/bomber -- one variant of this tested the Ne-30 jet engine, and that could provide a historical basis for transition to jets at higher tiers; see also P1Y2-S variant for possible Tier V ground-attack -- specs -- images -- jet project also known as Kugisho-Yokosuka Tenga -- NASM
• Mitsubishi Ki-51 -- 424 km/h -- ground-attack -- 2x12.7mm Ho-103, 1x7.7mm rear, 200kg of bombs -- specs -- images
• Mitsubishi G3M -- 375 km/h -- ground attack -- 4x7.7mm Type 92, 1x20mm rear, 800kg of bombs -- specs -- images

 

         Low production

• Mitsubishi Ki-83 -- 686-762 km/h -- heavy fighter -- notes --  2x20mm, 2x30mm, 2x50kg bombs -- also Ki-95, Ki-103 variants -- paint -- images
• Tachikawa Ki-94 -- 712 km/h -- name given to 2 airframes -- interceptor -- 2x30mm Ho-155, 2x20mm Ho-105 (W), 2x250kg bombs -- images -- story
• Kawasaki Ki-64 -- 690 km/h -- heavy fighter with 2 inline engines, contra-rotating propellers -- 4x20mm -- paint -- images -- details
• Kawasaki Ki-88 -- 600 km/h -- fighter -- 1x37mm, 2x20mm -- paint
• Nakajima J5N1-- 597 km/h -- heavy fighter, derived from J1N1 -- 2x30mm / 2x20mm -- paint -- images -- NASM -- 3-view
• Kawasaki Ki-60 -- 560 km/h -- fighter -- 2x12.7mm (S), 2x20mm (W) 
• Mitsubishi Ki-109 -- 537 km/h -- Ki-67 derivative used as heavy fighter -- 1x75mm Type 88 nose, 1x12.7mm Ho-103 Type 1 tail *** -- images
• Kawasaki Ki-28 -- 480 km/h -- fighter -- 2x7.7mm 
• Nakajima Ki-11 -- 420 km/h -- fighter -- 2x7.7mm Type 89 

 

 

OMITTED -- for one reason or another these do not fit into the current style of the game:

 

         IJN 

• Nakajima A6M2-N -- floatplane variant of the Zero -- specs
• Mitsubishi B2M -- torpedo bomber
• Yokosuka B3Y -- torpedo bomber
• Nakajima B3N-- torpedo bomber
• Yokosuka B4Y -- Navy's last biplane -- specs
• Nakajima B5N -- torpedo bomber -- specs
• Mitsubishi B5M -- torpedo bomber -- specs
• Nakajima B6N -- torpedo bomber -- specs -- NASM
• Aichi B7A -- dive bomber -- specs -- NASM
• Nakajima C3N -- recon
• Mitsubishi C5M (Ki-15) -- recon plane / light bomber -- specs
• Nakajima C6N -- recon -- NASM
• ​Aichi D1A -- dive bomber -- specs
• Aichi D3A -- dive bomber -- specs -- details
• Yokosuka D4Y -- dive bomber -- specs
• Kawanishi E7K -- floatplane -- specs
• Nakajima E8N -- floatplane -- specs
• Aichi E10A -- floatplane
• Aichi E11A -- floatplane
• Aichi E13A -- floatplane -- specs
• Yokosuka E14Y -- floatplane -- specs
• Kawanishi E15K -- floatplane
• Aichi E16A -- floatplane -- 2x20mm, 1x13mm rear, 1x250kg -- 439 km/h -- specs
• Mitsubishi F1M -- floatplane/biplane recon
• Mitsubishi G4M -- ground-attack, many variants, leads to the Yokosuka P1Y -- specs -- NASM
• Nakajima G5N -- heavy bomber
• Nakajima G8N -- four-engine strategic bomber
• Nakajima G10N -- ultra-long-range heavy bomber -- details
• Kawanishi H3K -- flying boat
• Yokosuka H5Y -- flying recon boat
• Kawanishi H6K -- flying boat -- specs
• Yokosuka H7Y -- flying boat
• Kawanishi H8K -- flying boat -- specs
• Aichi H9A -- flying boat
• Kawanishi H11K -- flying boat
• Kawanishi J3K
• Kawanishi J6K
• Mitsubishi J8M (Ki-200) -- rocket-powered interceptor -- details
• Kawanishi K-200 -- jet-powered flying boat
• Aichi M6A -- floatplane -- NASM
• Yokosuka MXY7 -- suicide rocket -- specs -- NASM -- NASM -- NASM
• Kawanishi Baika -- suicide pulsejet
• Mizuno Shinryu -- rocket-powered interceptor / suicide

 

         IJA 

• Mitsubishi Ki-2 -- light bomber
• Mitsubishi Ki-20 -- bomber -- details
• Mitsubishi Ki-21 -- bomber -- specs
• Mitsubishi Ki-30 -- light bomber -- specs
• Kawasaki Ki-32 -- light bomber -- specs
• Mitsubishi Ki-33 -- fighter -- premium code in "Computer BILD Spiele" magazine -- or buy a shirt -- spec comparison
• Tachikawa Ki-36-- observation / light ground attack -- specs -- details
• Kawasaki Ki-48 -- light bomber -- specs
• Nakajima Ki-49 -- medium bomber -- specs
• Mitsubishi Ki-57 -- transport -- specs
• Kawasaki Ki-66 -- heavy dive bomber
• Mitsubishi Ki-67 -- heavy bomber -- specs
• Tachikawa Ki-70 -- recon -- details
• Mansyu Ki-71 -- canceled ground-attack based on Ki-51
• Mitsubishi Ki-73
• Tachikawa Ki-74 -- long-range recon
• Nakajima Ki-82 -- bomber, Ki-49 derivative
• Kawasaki Ki-91 -- bomber
• Mitsubishi Ki-112 -- bomber, Ki-67 derivative
• Kawasaki Ki-119 -- bomber
• Rikugun Ki-202 -- rocket-powered interceptor -- details
• Kayaba Katsuodori -- story -- images

 

         Imports

• Heinkel A7He -- imported
• Hienkel He111 -- canceled import, bomber
• Fiat BR.20 -- imported, medium bomber
• Bücker Bü 131 -- imported = Kokusai Ki-86 / Kyushu K9W
• notes about German influence here and here

 

 

DIVE BOMBERS -- ​If dive bombers were included as a new category and offered as a parallel track, they might look like this:

 

          

 

According to one author (book at library, I will find the author later), the the Aichi D3A "Val" was the most effective dive bomber, though its role was replaced by A6M fighter-bomber and to a lesser degree by D4Y Suisei.

 

 

PREMIUMS -- speculation about what the premiums might be:

 

Below is a very ambitious (highly theoretical) version that tries to incorporate every viable plane regardless of progression, prototype or project (indicated by orange outline).  The goal here is not to outline a reasonable progression as above, but rather to derive some upper limits about what might be expected should the Japanese tech tree ever be expanded.  Conclusions:

 

• The main Nakajima IJA fighters are not likely to be offered as premiums because they would be needed instead to form the core of a new line of progression (see Navy precedent).
• The Japanese tech tree is very likely to include prototypes as part of progression if heavy fighters or ground attack roles are to be materialized.
• The Japanese tech tree is unlikely to have more than 30 aircraft (and their variants).

 

Note:  This is an older version of the proposed tech tree but it is still valid for the purpose of establishing upper limits.  It may be updated but it is low priority.

 

 

OTHER CLUES -- based on current content in game:

 

         MEDALS

• Akamatsu -- flew the A6M but also flew the J2M.

 

         EMBLEMS

• Black and white symbol -- appears on the tail of a Nakajima Ki-27, Nakajima Ki-43, Nakajima Ki-44, Nakajima Ki-61
• Green clover -- appears on a Kawasaki Ki-61-I Hien flow by Captain Akihiko Kobayashi, 244th Sentai
• Red arrow -- appears on the fuselage of a Kawasaki Ki-45
• Yellow arrow -- appears on the tail of a Kawasaki Ki-45
• Yellow sun -- appears on the tail of a Nakajima Ki-84
• Weave pattern -- appears on the tail of a Nakajima Ki-61
• Bomb pattern -- appears on the tail of a Nakajima Ki-61
• White angular pattern -- appears on the tail of a Nakajima Ki-61
• Lightning-Bridge pattern -- appears on the tail of a Nakjima Ki-44

 

 

 

 

Not bad but you seem to have forgotten a few others:

Kogiken Plan 1 Type A

Kogiken Plan 1 Type B1

Kogiken Plan 1 Type C   --- also identified as the Ki-124-1... the Japanese version of the German Do 335

Mitsubishi-Payen PA 400

The A7M3 version needs to be made available.. the one with the Ha-43 supercharged engine.

 

... I have included a list I wrote and submitted in suggestions some time ago:

Mitsubishi-Payen PA.400
J1N1 Gekko
Ki-94-I
Ki-94-II
Ki-88
Ki-98 (Ground Attack)
Ki-102 (Ground Attack)
Ki-46-IIIB (Ground Attack)
Ki-45 (Heavy Fighter)
Ki-46-III Kai (Heavy Fighter)
Ki-73 (Heavy Fighter)

Ki-78 (High Speed Fighter)
Ki-64 (Heavy Fighter)
Ki-93 (Heavy Fighter)
Ki-96 (Heavy Fighter)
Kogiken Plan 1 Type A (Heavy Fighter)
Kogiken Plan 1 Type B1 (Heavy Fighter)

Kogiken Plan 1 Type C (Heavy Fighter)( Ki-124-1)  <---- Japan's version of the Do 335
Ki-102 (Heavy Fighter)
Ki-108 (Heavy Fighter)
R2Y Keiun
Ki-61-I
Ki-61-II ( high altitude fighter )
Ki-84-IC (high altitude fighter)
Ki-87-I (high altitude fighter)
Ki-87-II (high altitude fighter)
J2M4 Model 32 Raiden (high altitude fighter)
J2M4 Model 33 Raiden (high altitude fighter)
J2M4 Model 34 Raiden (high altitude fighter)
Ki-100-I
Ki-100-II (high altitude fighter)

Ki-117

Ki-119
N1K1, 2, 3, 4, 5 -J
J3K1 Type 17 (Interceptor)
J6K1 (Interceptor)
Ki-201 (Jet)
J8N-1 Kikka (Jet)
Kayaba Katsuodori (Jet)
Ki-162 (Jet)

Edited by Olde_Crow, 11 March 2014 - 10:37 PM.

[J311yfish]

Olde_Crow, on 11 March 2014 - 11:26 PM, said:

Not bad but you seem to have forgotten a few others:

Kogiken Plan 1 Type A

Kogiken Plan 1 Type B1

Kogiken Plan 1 Type C   --- also identified as the Ki-124-1... the Japanese version of the German Do 335

Mitsubishi-Payen PA 400

The A7M3 version needs to be made available.. the one with the Ha-43 supercharged engine.

 

Kogiken series:

 

-- group of engineers assembled in summer 1941

-- designs were nearly complete by September 1941

-- led by Lieutenant Commander Ando Sheigo

-- the task was to study all known aviation technology (Japanese as well as other countries) in order to determine what might be possible in the present and near future

-- from the results of these studies the group was to draft proposals for aircraft that might take advantage of their forward-thinking  (like a skunk works)

-- they identified 4 roles or "plans" (heavy fighter, light bomber, heavy bomber, reconnaissance) and a fifth plan (high speed) to be incorporated into the previous 4.

-- none of the Kogiken aircraft were constructed; it produced instead ideas that went into the development of other aircraft

-- Dyer gives these examples:  Ki-64 using Ha-201 coupled engine with a surface evaporation cooling system; Kawasaki Ki-88 using fuselage-buried Ha-140 to drive propeller via extension shaft; Mitsubishi Ki-46-III may have benefited from aerodynamic streamlining studies.

-- there are 9 pages devoted to discussion of the plans (concepts, proposed engines, armament, variations), but no mention of a Plan 1 Type C.  However ...

 

Here is what Dyer says about the Dornier Do 335 Pfeil fighter bomber:

-- "it was believed that the Japanese were provided with a description of the Do 335 in March 1945 but no substantive information was released to them."

 

If all of that information is accurate then it suggests that the Type C might be a fiction because it doesn't fit chronologically.

 

Source: Edwin Dyer

 

Mitsubishi-Payen Pa.400:

 

-- French aircraft designer Nicholas Roland Payen

-- designed several unusual aircraft (trapezoidal fore-wing with ailerons + rear delta wing with horizontal control surfaces)

-- French military showed no interest

-- 1938 Mitsubishi expresses interest in Payen's designs; Payen meets with IJN representatives

-- Payen adapted his Pa.112 concept to be a carrier-borned light bomber, to be called Pa.400

-- September 23 1938, French government authorizes sharing technical information

-- project abandoned either due to Payen not sharing the information on the brink of war, or IJN losing interest

-- Dyer explains several technical limitations of the design that may explain possible loss of interest by IJN

-- no prototypes produced

 

Source: Edwin Dyer

 

A7M3:

 

-- A7M3-J concept was to be powered by turbosupercharged version of the MK9A; max speed 649 km/h at 10,000m expected

-- design complete November 1944

-- mock-up inspected February 1945

-- prototype planned for October 1945, interrupted by surrender

-- a further development of the A7M3-J (using a different engine, and carrier-based) was left on the drawing board at surrender

-- A7M3 Model 23 was to be designed around MK9C with a mechanically-driven three-speed supercharger; 642 km/h max speed expected at 8700m

-- Model 23 favored over the J because it could use the A7M2 airframe without major redesign

-- armament to be 6x20mm Type 99 Model 2's in the wings

-- scheduled to be completed by December 1945, interrupted by surrender

-- no prototypes produced

 

Source: Rene Francillon

 

 

I will look closer at the other aircraft in your list.  If you can recommend sources other than Francillon or Dyer I would be glad to check them out.

 

When I began this project I had to set several rules for myself in order to have a clear direction.  One of the rules was that I was going to give preference to high-production aircraft (those that were actually in the war); yet I have discovered that the tech trees of other countries do not necessarily adhere to that rule.  The Russian attack line for example has several IL's that never had more than 10 produced, yet they are there presumably to complete the line and offer an alternate path of progression.  Another example is the Bf 109 Z (only one built, but never flown).  I could certainly use the that precedent (or the J7W3) to devise any tree I want in the name of fun, but then it becomes deeply subjective and not very useful for making predictions.  

 

I don't know how to account for the "fun factor" but I imagine it would involve identifying different themes and trying to work them into the tree, such as:

-- a fighter line that focuses on speed and rate of climb rather than maneuverability

-- a discernible ground attack line

-- a discernible heavy-fighter line or "night fighter" concept if maps are made to be dark ***

-- a dive bomber line if it becomes relevant

 

Anyway, I'll leave the "fun factor" to developers because it is their business and I think they've done a great job so far.  I'm kind of hooked if you haven't noticed.  If nothing else comes of this tech tree adventure then it has certainly been fun just learning about all of the different aircraft.