WITP Book' A little spare time.. the next Hibiki?

[Commander Stormwolf]

Hello WITP community,

I have the idea to write a historical-fiction book
called "Koku Hombu' .. if the air forces had co-operated

tentative title [;)]

basically it is putting me as the air minister of the combined japanese air force
and, it is (using the least possible hindsight) what i would have done, including the mistakes
i made, if i was put in charge of japanese AC research and production starting from Dec 1941

just a first draft of the first chapter sort of.. it's kind of a technical history book similar to "Zero Fighter",
without the warped political views

[Commander Stormwolf]

page 1

If the air forces had co-operated..

Koku Hombu, the story of the imperial japanese air force in 1941-1945


The combination of the army and navy air forces in September 1941 was heralded as a great achievement.
Catching up to the europeans was a challenge, japan was a great deal behind even the weakest
of the powers having fought and lost the air battles above khalkin gol two years prior.

Having made the decision to go to war, the challange now remained how best the forces could
be employed to achieve victory, or an acceptable settlement.

Japanese aviation was both quantitatevly and qualtitatevely behind the western powers,
however both pilot training and experience gained during the sino-japanese war were expected
to make up for the diference in materiel.

In October of 1940, the war in europe had been waging for some time. France had been overrun
and was under the dominion of nazi germany. The battle of britain had resulted in a stalemate
above the skies.

Japanese observers were sent to witness these events, and several conclusions were made.

1) Twin-engined fightes such as the Bf-110 were ineffective in the offensive and escort role,
suffering heavy losses to the highly maneouverable and less expensive single-engined fighters.

2) A long-range escort was required for offensive missions, the Bf-109E was ineffective.

3) The 20mm cannon was the most effective form of armament, and is even more devastating when
combined with a fast-climbing interceptor, to which the Bf-109E is well suited.

4) Speed first and maneouverabilty second are essential to the modern dogfighter, of which the Spitfire
is the best in the world

5) armor was desirable for protection against the defensive fire of enemy bombers

[Commander Stormwolf]

page 2

These conclusions were in some contravention to the accepted principles of japanese aviation
until that point. The japanese had been fighting largely obsolete designs in china, and
the development of larger engines and faster fighters had stagnated somewhat.

In January 1941, the annual air contest was held between the japanese air force and the japanese navy.
This was done to promote the spirit of competition, so aviation designs could be evaluated.


The army had submitted three different planes, the Type 97 fighter with a fixed undercarriage
and high maneouverability; the Shoki interceptor with a large radial engine and high rate of climb;
and the Hayabusa long-range fighter.

The navy had submitted only one type of fighter, the Reisen IIb carrier fighter that had proven
itself in the skies above china.

A number of foreign designs were also present, but were not included in the dogfight competition.
The most prominent of these was the Heinkel He-100D-0, a highly advanced design from germany
with top speed of 420mph.

It was concluded that the Type 97 and Hayabusa were inferior to the Reisen IIb, the Shoki being
slightly faster and with a better rate of climb. The He-100 was not included in the assesment.
It was understood by some that the japanese designs would have been totally outclasses by the He-100
if it were allowed to participate. It was another example of the anxiety present in the japanese aviation circle.


With the oil embargo in place, japan was on the road to war. It was concluded that four main types of fighters
were required.

1) An air-superiority fighter with high speed
2) An interceptor with heavy firepower and armor
3) A long-range escort
4) A carrier fighter

[Commander Stormwolf]

page 3

These categories had to be satisfied, with performance figures as good or better than their impending adversaries,
the RAF and USAAF. The first category was difficult to satisfy. It required the use of an inline liquid-cooled engine
with which japan had little experience. Japan had obtained the license to build the DB-601 engine from germany,
an 1175hp engine that was adequate for the task, however difficulties were present with establishing a reliable
unit for mass production and therefore delays were encoutered.

The Kawasaki team had some experience with liquid cooled designs, having made the Ki-10 and Ki-28 fighters
however their modern examples such as the Ki-60 had proven a dissapointment. Lessons had been learned from
the He-100 and the knowledge of past failiures was included into the design of the Hien.

For the category of air-superiority fighter, the following priorites were made:
1) speed of 425mph or more 2) low wing loading 3) firepower of 2x20mm cannons 4) medium range


The Kawasaki team had been tasked with making the Hien ready, and all its other projects had been cancelled.

Takeo Doi was tasked with meeting the requirements. How was the Hien supposed to meet the speed specification?
The first prototype was expected to have a speed of only 373 mph, that while being armed with 2x12.7mm machine guns
in the nose and 2x7.7mm machine guns in the wings. Doi was also convinced that armor was necessary for the modern fighter,
and it had been included as part of the original design.

[Commander Stormwolf]

page 4

Doi was given access to one of the three He-100 prototypes acquired by japan and he spent a great deal of time studying it.
The Hien was encumbered by the aerodynamic flaw of a ventral radiator that caused much drag and it was decided to
adopt the wing cooling evaporative system of the He-100. Although this would make the fighter more vulnerable to battle
damage, it was necessary to meet the specification. The prototype was now expected to achieve 395 mph.

The firepower specifcation had now been increased. It was decided by the minister for fighters that the best arrangement
for an inline-engined fighter was 3x20mm cannons, two on top of the cowling and one firing through the engine V.

Doi was upset by this idea. It was difficult to install the cannon in the center, and he spent more time studying the He-100
to see how this was achieved. Little known to him, this arrangement was the standard on the new fighters such as the Bf-109F
and Yak-1. Japan had only two types of 20mm cannon available. The first was the Ho-3, a long barreled high-velocity gun
and the second was the Type-99-1, a short-barrel, low-velocity gun. The Ho-3 could not fit on the cowling of his fighter,
so the lighter Type-99-1 was selected. Space was made for large magazines each housing 200 rounds.

His fighter was not going to make the specification unless serious weight reductions could be made.
Despite being designed with armor protection in mind, he was forced to abandon the bulletproof glass, armored seat,
and self-sealing fuel tanks.

When his new fighter took to the air, it achieved 420mph at 12,430 feet. His meat-trimming had lowered the
loaded weight to 2600kg giving a wing loading of 130kg/m2. Sleek, streamlined and deadly, the 3x20mm cannon armament
was waiting to tear into the fat and flesh of curtiss, bell, grumman, and hawker.

Pilots were enthusiastic, no-one complained about the lack of armor until the shooting started.


Engine delays meant the Hien did not enter production until July 1942

[Commander Stormwolf]

page 5

As a safetey measure against the failiure of the Hien, the Hitachi team had been instructed to
begin the measures for production of the He-100. The jigs and tools had not arrived from germany,
however the japanese designers had great experience with reverse-engineering foreign designs.
The He-100 prototypes had been in japan for more than a year, and it was decided to make use of them.

It entered production in July 1942

[Commander Stormwolf]

page 6

The second category of fighters was the role of interceptor.
The main hope for this category was the Shoki airframe designed by the Nakajima fighter team
under Yasushi Koyama. He was ordered to stop all development of the Hayabusa airframe and make
the Shoki into a good interceptor for protecting the assets that would be captured by japan

Priorities for the interceptor were as follows:

1) Rate of Climb of 4,000 fpm 2) Firepower of 4x20mm cannons 3) Speed of 400 mph 4) Armor 5) short range

The main difficulty was selecting a good engine. The Nakajima company had been humiliated by a
series of poor engine designs, beginning with the Mamoru 1870hp radial, an engine that caught fire after
only minutes of operation and caused the delay of the Tenzan torpedo plane and Shinzan heavy bomber.

The engine used by the Shoki prototypes was also poor. The Ha-34-11 was only capable of 1250 hp and would be
inadequate for this purpose.

The only answer was to use the Mitsubishi Ha-32-12 engine, a 1530hp radial.
It was not uncommon for japanese planes to use engines of competing companies. The Reisen carrier fighter
had used the Sakae engine made by nakajima, and now the favour had been returned.

Koyama was occupied with his pursuit of the next-generation fighter and spent much of his time designing
the Hayate. The Shoki with its new engine would not be ready when the war broke out. Koyama was being threatened
by an inquiry and was hastily forced to slap together his mock-up. The prototype flew and no-one knew how the
Shoki IIc interceptor would perform. The results were a testament to the excellence of the Ha-32-12 engine.

Top speed was 397mph and climb rate was an excellent 4225 fpm. Two Ho-3 cannons sat on the cowling and two more
stuck out of the wings, each with 200 rounds. Loaded weight was 2480 kg, giving a wing loading of 165 kg/m2,
still acceptable to the pilots. For the first time, a japanese fighter pilot was protected with glass, armored seat,
and self-sealing tanks. All of this was achieved by reducing the fuel capacity, and the pilot was restricted to
a flight time of just 30 minutes. External fuel tanks were required, even for standard patrols.

It entered production in March 1942

[Commander Stormwolf]

page 7

The third type of fighter was the long-range escort.
The Reisen IIb already had a long range capability, however the torpedo planes such as the
Rikko and Hamaki could operate even further so it was decided to increase the range of the Reisen.

To achieve this, both the internal and external fuel capacity would be increased.
A new engine was selected, the more powerful Ha-35-21 with 1130hp verus the old 980hp.
It used a 2-speed supercharger so it could operate well with the bombers at high altitude, however
it also meant a slightly higher specific fuel consumption and higher weight.

The only way to further increase the internal fuel capacity of the Reisen was to adopt the integral wing tanks
of the Hamaki, making it even more vulnerable to battle damage. The 20mm weapon bays were replaced with fuel tanks
and the short Type 99-1 20mm cannons were put on the engine cowling, replacing the smaller 7.7mm machine guns.
The external fuel capacity was increased as well. The maximum external load of the Reisen IIb was 1x330L external drop tank
under the fuselage and two 60kg bombs in the wings. The escort was not required to perform any bombing missions,
so the wing hardpoints were replaced with two small 100L drop tanks.


Out of these requirements, the Reisen IIIe escort fighter had emerged.
It had a top speed of 338 mph, with a low 113 kg/m2 wing loading.
It carried 700L of internal and 530L of external fuel, giving it a range 35% more than the Reisen IIb.

It entered production in June 1942

[Commander Stormwolf]

page 8

The category of carrier fighter was also left to the Mitsubishi team, designers of the Reisen IIb.


The Reisen IIb was flown by the expert pilots of the japanese fleet air arm, mainly aboard their carriers.

There were many arguments during the design process of the Reisen IIb. Jiro Horikoshi had once been invited to a
large banquet meeting with the aeronautial staff and he had said it was not possible to make a fighter to satisfy all
the demands of the specification given to him, that speed, range, and dogfighting ability were not mutually exclusive.

The replies came one by one, some officials saying that range was essential to protect the long-range bombers
and others that short range was acceptable if it meant that the dogfighting ability was superior.

What resulted was the Reisen IIb, a plane that fit neither category very well. It did not have the range to escort
the land-based bombers to their full combat radius, while it was less maneouverable than the fighters it was replacing,
and at a slow 328 mph, certainly would be inferior in combat with the 400mph fighters of the allies.

The decision was made therefore to split the development of the Reisen into two categories, one for long-range escort
such as the Reisen IIIe and one for the short-range carrier fighter role.

By reducing the fuel load, an excellent dog-fighter could be made.

The Reisen IId was a simple conversion.

Loaded weight was a small 2115kg, giving a wing loading of 94.3 kg/m2, down from the 107.4 kg/m2 of the Reisen IIb.

Top speed was increased to 349 mph, up from 328mph.

Range was shorter, but sufficient to escort the carrier planes to their full combat range so long as
a drop tank was used.

[Kubel]

Count me in...best of luck.

[Terminus]

Good luck with it, but maybe classify it as Fantasy Fiction instead.

[tocaff]

A lofty goal and maybe a bit presumptuous to target Cuttlefish's work. 

Good luck.

[Commander Stormwolf]

parge 10

The evolution of fighters


The first fighters were built during the first world war.
Engines were typically of about 100 hp, and they each mounted
a single 7.7mm machine gun. The first designs were monoplane such as the Fokker Eindecker,
and then progressed into biplane and even triplane configuration.

The main reason for adding layers of wings was to increase the rate of turn of the aircraft,
as the basic dogfighting tactic is circling onto the opponent's tail and shooting him down
from behind. This is achieved by reducing the wing loading, meaning the amount of weight
of the fighter divided by its wing area.

A fighter will lose speed as it begins to turn,until it begins to stall.
The low wing loading allows the fighter to balance in the air.
Allied fighters such as the Nieuport 17 biplane had a very low wing loading,
the fighter weighed 560 kilograms and its wings covered an area of 14.75 m2. So its weight
per area was 38 kg per m2. The Nieuport 17 was a favourite of pilots who used the Lufberry circle,
until the enemy would stall and become an easy target.

[Commander Stormwolf]

page 11

As engines became more powerful, the fighters became heavier and new solutions between the wars
were being sought to solve the problem of wing loading. A heavy fighter will have a poor rate of
turn so one must either increase the size of the wings (thereby increasing weight and drag),
reduce the fuel and weapons load (making the fighter less useful), or attempt to use new materials.

The biggest innovation between the wars was the widespread introduction of duralumin.
The new material was much lighter than steel and wood, but was more difficult to produce in large quantity.

An air force with an emphasis on size had to made some choices, either produce fewer planes of superior
performance or a large number of planes with worse performance. To japan, there was no choice.
Duralumin was available in sufficient quantity, and there was no spare industrial capacity
to produce enormous amounts of planes. Furtheremore the fuel quality in japan was poor.
In the USAAF, 100 octane was the standard. It meants that using wood and steel was out of the question.

[Commander Stormwolf]

page 12

The RAF had entered the war with two main fighter designs,the Supermarine Spitfire
and the Hawker Hurricane.

The Spitfire I was regarded as the most advanced fighter in 1939. Built of pure duralumin,
the airframe was light and streamlined. For the first time, both speed (362 mph) and agility
(120 kg/m2) were combined into a single fighter.

Using the same engine, and 1100hp merlin, was the Hawker Hurricane. It was an intermediate
design using some components of the old biplanes, and was constructed of steel tubing and wood.
It was less advanced aerodynamically. The Hurricane also had the same weapon load as the Spitfire
(8 x 7.7mm) but its performance was about 10% worse than the Spitfire.


In combat the Hurricane was matched by the Bf-109E, but the Spitfire was superior in all respects.
Therefore the anatomy of a fighter is a difficult one. Even with the same powerplant and
general configuration, a completely different plane can result based on the aerodynamics and materials.

[Commander Stormwolf]

page 13

It was generally accepted that a 10% increase in performance would result in a 2-1 advantage in exchange
so every small advantage was sought.

In germany, the emphasis was on a large quantity of production, so the Bf-109E was selected above the
superior Heinkel 100. The Bf-109E could be assembled in 5,000 hours.
The Hawker Hurricane could be assembled in 10,000 hours, whereas 15,000 hours were required by the spitfire.

Even so, Luftwaffe production had been eclipsed by the RAF during the battle of britain, due to superior factory
organization and the long hours put in by their workers.

[Commander Stormwolf]

page 14

The largest air force in the world, the Soviet VVS was intent to achieve quantitative supremacy and the only way this
was possible was to sacrifice the quality of materials. Designers were forced to use wood, but were expected to
create superior performance. After studying the Heinkel He-100 prototypes, three main types of fighters were put into
production. The first was the Mig-1, of which about 100 were made. This fighter, created by men in prison and
build of wood and steel achieved a top speed of 408mph. Range and weapons load were small, but this did not matter, it
was a world-class design. Even once self-sealing fuel tanks and armor were included, it still could achieve 398mph.

The Yakovlev design burean had decided to create a different type of fighter. Sharing its design concepts with the
Spitfire, a larger wing and lighter engine were selected to make a maneouverable fighter. The Yak-1 was also fast
at 368mph.

Finally the Lagg group had made a monster. Designed to use the minimum of strategic materials, it was built completely out
of laminated wood and was intended to fill the ground support and anti-bomber roles. It was slow and heavy, but it could be made
in large numbers so it was kept in production.

All three designs were fitted with liquid cooled inline engines, with a large caliber weapon firing through the propeller
and two machine guns on top of the nose. The same principle was applied in the Bf-109F.

[Commander Stormwolf]

Chapter 2: The state of readiness for war

On June 21, 1941 when Germany attacked the Soviet Union, the Luftwaffe had more than 2,000 BF-109 fighters
in its inventory. On the eve of December 7, 1941 japan had 436 fighters in service.

Of these were 328 Reisen IIb fighters, of which half were stationed aboard the carriers.

There were 89 Hayabusa Ic, a design that was put in production to the dismay of its pilots.
There were also a flight of 9 Shoki I prototypes and another flight of 10 Toryu IIa prototypes.
.
The remainder of the inventory was obsolete models and trainers, such as the Type 96 (217 examples)
and Type 97 (982 examples), fighters with fixed undercarriages.

It was a precarious situation, either accepting numerical inferiority on the battlefield or pressing
experienced aircrews into obsolete planes.

Japanese fighter production was appaling. During November 1941, only 53 Reisen and 29 Hayabusa fighters
were delivered.

[Commander Stormwolf]

What was required was to make the best use of the assets available. Under the new unified organization,
the navy carriers and surface ships were part of the fleet air arm, commonly known as the mobile command.

Fortunately, japanese bombers were available in larger quantity. The fleet air arm was able to put together
182 x Kankoh II and 106 x Kankoh I (alled codenamed Kate), 79 x Type 96 Kankoh (Jean)
and 31 x Type 97 Kankoh (Mabel), together 398 torpedo planes.

Carrier dive bombers were also available, including 191x Kanbaku I (Val) and 68 x Type 96 Kanbaku (Susie),
altogether 259 dive bombers.

The assets were limited, however the tasks of the mobile command was significant. It was expected to
neutralize enemy sea and air power during the amphibious landings. Also it was expected to fight a
preliminary naval engagement that would weaken the allied counter-attack and allow japan to hold onto
its new territory.

[Commander Stormwolf]

The air groups were divided into four categories. Shield, Shepherd, Reduction, and Battle

Shield was composed of the A1 and A2 fighter divisions, a total of 162 Reisen IIb fighters
and the best pilots, who were tasked with protecting the carrier force.

Shepherd was composed of A3 and A4 fighter divisions, flying the obsolete Type 96 fighters
and with less experienced pilots, were to provide an escort for the strike units.

Reduction was composed of the inexperienced strike units, mainly flying the Type 96 torpedo plane
and type 96 dive bomber, who were tasked with attacking airfields and other targets in support
of amphibious landings.

The Battle corps was the elite strike units B1 and B2, and D1 and D2, expected to fight the naval battle and would be kept
in reserve until then. They were flying 162 x Kankoh II and 162 x Kanbaku I torpedo and dive bombers.

There were also 98 x Type 0 Reconnassance floatplanes (Jake) and 118xType 95 floatplanes (Alf) available
for naval spotting.