Koku Hombu Episode 1 ~ Let's Make a Fighter

[Commander Stormwolf]

Greetings Witp Community,

So i am writing some type of historical book about fighter design

wondering what ideas exist for the important features of a fighter

let's say you are expected to configure a fighter to save japan and
win the air war against the allies

here are the choices:


Engine: Small Radial, Large Radial, Inline

Armament: 7.7mm, 12.7mm, 20mm, 37mm

Mounting: Wings, Centerline

Materials: Strategic (Duralumin), Non-Strategic (Wood-Steel)

Fuel Load: Large, Small

Externals: Ordnance, Drop Tank


limited to historical airframes and engines

my field of knowledge is aeronautics so give me a config and
i can use some formulas to make a cool pic

[Commander Stormwolf]

like this one

*someone asked what does A6M2 look like with 4x12.7mm instead of the 2x7.7mm + 2x20mm

[btbw]

Dont know why you downgrade Zero, but his ceiling was 30k feet.

[Commander Stormwolf]

ah yes, this is an old photo from an experimental mod

but the bit of extra weight does reduce top speed by 3 mph and wing loading by about 2.5kg/m2

[Commander Stormwolf]

hehe would be pretty cool if the editor had a schematic tool
that tells you the performance results when you change the parts [;)]

[mdiehl]

Well, no Japanese design was going to WIN the war, even when you ignore the fact that they ran out of trained pilots. So you have to wonder what such a plane is supposed to do.

I'd say, a late war design would have to force the Allies to invade and bring about that massive battle of attrition that the Japanese thought (incorrectly or not) would bring about a "negotiated peace."

I figure the only way to do that is stymy the US strategic bomber effort. That means knocking down lots of B-29s and forcing them to fly at high altitudes. At this point in the war, you're dealing with USAAF bombers that have vastly better gun targeting systems than the Japanese fighters thrown against them. So you need something that is very fast, very tough, can sustain plenty of battle damage, and deliver a lethal dose in a single firing pass.

Then you hope that MacArthur's ego wins out over the US Navy's recommendation of blockade-and-wait.

That means, IMO, something like a P-47 or F4U armed with four 30mm cannon knock-offs from the late war Luftwaffe cannons rather than the clunky 20mm meatball-tosser that the Japanese used in the Zeke.

Problems abound though. They tried designing 3rd generation fighters but none of the late war Ki's or Nakajimas were reliable enough to achieve their demand specs in actual field use.

[Commander Stormwolf]

Shinden probably could have been available by 1/45 (six months sooner)
if watanabe didn't waste any time on the Q1W Lorna

Putting the J2M's 1850hp Kasei into the Ki-44 would have been a good idea

also take out the fuel to increase speed....

.. europeans learned that more fuel = less speed (FW-190 long range variants, Yak-9DD, etc)

[tocaff]

So now we're talking about a point defense fighter that is very fast, very durable with a big punch.  A small plane with 2 X 30mm, lots of armor and an inline engine?

Given the production problems and lack of skilled pilots I don't think they would've been able to achieve the desired results.  The fighters that did fly in the later stages of the war didn't press home attacks on the B-29s except for rare cases.  Those bomber formations bristling with weapons that were accurate was hell on the targets.  Of course there was also the problem of American fighters to be dealt with also.

[Commander Stormwolf]

To deal with B-29s the Shinden was a good idea - canard wing gives excellent aerodynamics
Large 2100hp Radial engine, 4x30mm, armor

Where japanese aviation failed was the failiure to keep their midwar designs modern


Imagine how weak the USAAF would have been if they kept 1200hp Allison engines on the Mustang..
A6M8 was available since January 1943, with the Kinsei 62 engine

Best midwar fighters:
Reisen with Kinsei 62, no armor, 2x20mm on the cowling, medium fuel (just enough to escort the Jills and Judys)
...those massive weight reduction would give a pretty good speed in the range lof 380-390 mph and high Mvr

Ki-44 Shoki with Ha-32-21, 4x20mm, the absolute minimum of fuel, use drop tanks for CAP.

As an airframe, the Ki-44 was the most advanced radial fighter design until maybe the bearcat.
The smallest airframe (15m2 wings [X(]) with the largest engine, remarkable climb rate is obvious.
If the heavy wooden La-5-fn uses an 1850hp engine to make 400mph, the Ha-32-21 shoki would make about 415-420mph,
giving it a comparable top speed with the corsair.

Japanese fighters fell behind in speed and firepower, this was critical during the 1943 defense of New Guinea and Rabaul.

[mike scholl 1]

The problem with all this "Imagineering" is that Japanese industrial standards simply weren't up to most of it. Even with German blueprints, they were short on machine tools, quality control, high tolerance engineering, metalurgy, etc.. The industrial base simply wasn't there to deal with advanced designs.

[Commander Stormwolf]

japanese aviation factories were on average less mechanized than other,
it meant a large number of man hours per plane (usually about 25,000 versus about 10,000 for allied)

that being said, allied quality standards are overstated as well
soviet fighters were hit-or-miss, some factories pumping out fighters below spec.

Even the US fighter production was inconsistent. Brewster made about 1000 corsairs that were
completely out of spec, disintegrated in the air, were rejected and led to the bankruptcy of brewster.

the low reliability of the Homare and Mamoru engines were due to design flaws (Ha-45 was trying to cheat, running at high RPM
to get more horsepower, so of course it won't be reliable) and low quality fuel (less HP for same engine mass as US engines)

The Ha-32 (Kasei) series of mechanically supercharged engines had high reliability, as did the Ha-33 series.

It seems that japanese design did everything possible to reduce weight of armament, engines, armor,
however they still pumped their planes full of fuel (fuel is heavy)

full cockpit armor weighs only 100kg, a pair of 20mm with 200 rounds each
only weighs about 150kg

what was always amazing to me how soviets built this thing (with an 1850hp engine) out of heavy wood
and it still had world class performance ... *drum roll* La-5-FN

[mdiehl]

Even the US fighter production was inconsistent. Brewster made about 1000 corsairs that were
completely out of spec, disintegrated in the air, were rejected and led to the bankruptcy of brewster.

Brewster was notorious. I don't think anyone expected them to meet spec and it is well that they were closely monitored. Most of the other a.c. producers not only met but actually exceeded spec. Quality control in US a.c. production was as good as it gets and better than anything the Axis could produce.

Mike Scholl has it about right, IMO. Japan could field a.c. with moderate output engines, but when they attempted to build high performance 3rd gen radials the machines' field performance made Boeing's problems with the early B-29 engines seem minor.

[Commander Stormwolf]

Inline engines were troublesome (lack of experience, trying to copy DB-601 design, etc)

Some radials were bad, some were good.

As a general rule, all Mitsubishi engines were excellent (Ha-32, Ha-43) except the turbocharged ones (Ha-32 Ru)
but Mitsubishi made 3-stage mechanical superchargers since 7/44 like they put into the J2M5

Nakajima could make small Sakaes just fine, but the rest were bad

In a world without politics, all japanese planes would be engined with Ha-32 and Ha-33 mitsubishi radials
(and the air ministry knew it, but nakajima insisted to put their junk into planes like the G5N and B6N
which lead to the failiure and delay of those designs)

Japanese strengths lay in the airframes themselves (especially the Shoki)

they used a high% of duralumin, and a variety of 20mm cannons they could fit on their cowlings

(but they did this too late, soviets and germans learned you need 20mm on the nose since 1941)

[mike scholl 1]

ORIGINAL: mdiehl
Most of the other a.c. producers not only met but actually exceeded spec. Quality control in US a.c. production was as good as it gets and better than anything the Axis could produce.

Mike Scholl has it about right, IMO. Japan could field a.c. with moderate output engines, but when they attempted to build high performance 3rd gen radials the machines' field performance made Boeing's problems with the early B-29 engines seem minor.

Another major problem the Japanese experianced was that to try and match Allied numbers, they had to try and implement Allied "mass production" methods---without America's 30 years of experiance. They didn't have the engineering background to "break down" complicated production into sometimes thousands of individual steps performed with specialized tools developed specifically for that purpose. Japan could never have imagined "Willow Run", let alone built it before 1965.

So when the Japanese tried to make it work what they got was an incredable percentage of "not accepted" parts and engines and weapons. It takes a specialized and well-developed machine tools industry to support "assembly line" production..., and Japan had no time to develope one.

[Commander Stormwolf]

It takes a specialized and well-developed machine tools industry to support "assembly line" production..., and Japan had no time to develope one.

but they could afford to spend a lot more time per aircraft because

a) had far less materials than US, so they will make fewer AC anyway
b) were not producing (millions) of other vehicles like US

http://ww2total.com/WW2/History/Product ... uction.htm

only hope was optimize the airframes that were available to obtain a tactical advantage

(remember US fighters had the inefficient wing mounted arrangement, their 20mm guns didn't work,
and they had to carry lots of fuel since they had the burden of attack)

[mike scholl 1]

ORIGINAL: Commander Stormwolf

It takes a specialized and well-developed machine tools industry to support "assembly line" production..., and Japan had no time to develope one.

but they could afford to spend a lot more time per aircraft because

a) had far less materials than US, so they will make fewer AC anyway
b) were not producing (millions) of other vehicles like US

http://ww2total.com/WW2/History/Product ... uction.htm

only hope was optimize the airframes that were available to obtain a tactical advantage

(remember US fighters had the inefficient wing mounted arrangement, their 20mm guns didn't work,
and they had to carry lots of fuel since they had the burden of attack)

This is a really silly arguement. Japan HAD to spend many more manhours per aicraft because their facilities, tools, and designs were much less efficient. A perfect example is the decision to issue a new rifle to the IJA. The process began in 1936, and was still going on when the war ended...., for a simple bolt-action rifle! Japan's industrial base was very backward compared to all the other combatants except Italy. In reality, General Motors outproduced Japan in war material.

[oldman45]

If your design can't compete with the P51 and have armor, I can't see it working. The 6 50cal's would utterly destroy what ever the Japanese put up there.

[Commander Stormwolf]

just explaining that japan is producing AC and ships, and nothing else in any large quantity

they only made some 2,000 tanks and SPG in the entire war

japan had a large population, granted a big chunk was enlisted but the workforce was still formidable
however their productivity was much lower

since they are not making tanks, trucks, jeeps,or anything else they can spend those 25,000 hours per plane
and even if they had the mechanization to reduce that number of manhours, they lack the duralumin tonnage to
produce such numbers as the US did (however they did have a lot more than the soviets (soviet did not really expand
the aluminum industry prewar, and even their new designs (Yak-1 and Lagg-3 were made of wood)

so then even if japanese mechanization was on par,
if japan had been producing larger numbers, it would mean poor performance planes
such as the Lagg-3 or some wooden oscars that flew 280mph [X(]

[Commander Stormwolf]

If your design can't compete with the P51 and have armor, I can't see it working. The 6 50cal's would utterly destroy what ever the Japanese put up there.

Yep. It's a tall order, but let's explain exactly what I did with this one [;)]

Okay the basic Ki-61-Ia had a top speed of 373 mph, that includes 2x12.7mm and 2x7.7mm,self sealing tanks, and pilot armor.
The basic Tony as is known to all.

Takeo Doi made a version of the Tony with the wing cooling evaporative system of the Heinkel 100, with the same specs
(Tony was a good design, but its ventral radiator was huge and cause a lot of drag, making the tony slow)

The top speed was 395 mph. Pretty good for an 1175hp engine. It wasn't produced since WCES makes the plane
more vulnerable to battle damage (IJAAF started demanding survivability by 1943)

now for this hypothetical design..

I did a big weight reduction of the fuel load. This 4 hexes range includes the drop tanks. Reduced the fuel load to
increase speed and Mvr just like the P-39N did to the P-39D. The 1175hp version makes about 420mph.

This is the Hien-Kai version with the 1400hp DB-605, armament is the 2xHo-5 on the cowling plus a Ho-5 in the propeller hub
just like all european fighters

It's more vulnerable than the Mustang, but the firepower would be devastating and 160kg/m2 wing loading makes it turn tighter than a mustang

Of course, it's only good for CAP missions [:)]

[Commander Stormwolf]

of course there is this little (big) fighter that you could make.. with a service rating 5