CHAPTER 4 - WWII JAPANESE AIR SERVICE - SECTION 4
TABLE OF CONTENTS
SECTION IV - EQUIPMENT
- GENERAL
a. The aircraft industry in Japan is not new. Until 1937 private firms experimented in design, as did like companies
in other countries. Following the outbreak of war with China, aircraft companies were licensed as direct government
contractors. As of 1944 there were at least 6,000 contractors and sub-contractors producing aircraft and their component
parts. Early methods have been replaced by modern assembly lines in newly built factories.
b. Western nations have been to inclined to discredit the aircraft built by the Japanese on the assumption that their
planes are merely copies and poor substitutes. It is true that present designs are based on ideas gathered from other
countries, but the adaptations are such that the designs of all the major comnponents are virtually new.
c. From the beginning there has been an effort to keep weight at a minimum. By this means Japanese planes gained
maneuverability, long range, and greater cruising efficiency with a high rate of climb. Safety and fire power were sacrificed
in keeping with the belief that military attributes of high speed and long range were more valuable. The theory has proved
effective in the case of fighters, but recent attempts to increase armore and fire power in bombers indicate that considerations
of larger bomb capacity and more protection have gained importance.
d. As of 1944 Japan was turning out not only modifications to previous aircraft, but entirely new designs in both
aircraft and engines; these recent developments have great potentialities. Emphasis is being placed on fighters,
interceptors, and comparatively light bombers of the torpedo and dive bomber class. The design and production rates are
good. Present experimentation indicates radical developments in future operational aircraft. Jet propulsion types may
be expected.
- ARMAMENT
a. General. The Japanese show very little originality on their aircraft armament, except in modifying foreign designs,
such as those of Great Brittain, United States, Switzerland and Germany. The only weapon might be called truly Japanese is
the model 89, Nambu type, magazine fed, aircraft machine gun which was converted from the Nambu ground machine gun. However,
even this is a modified Hotchkiss design. It appears that a great variety of noninterchangable types of ammunition exist
for aircraft guns of the same caliber.
b. Guns. The Japanese employ aircraft guns with calibers ranging from 7.7-mm to 37-mm. Details of each type are
shown in fig. 67.
- OTHER EQUIPMENT
a. Radio See Chapter 10
b. Oxygen Apparatus
- The design of the Japanese oxygen system and their parts are good. The high pressure system has been generally
disregarded in favor of a low pressure one, in view of the vulnerability of the former. The Japanese system
usually consists of the following parts: High pressure oxygen bottle, pressure reducing regulator, pressure
gauges, automatic regulator, and masks or tubes.
- There are two types of bottles. The first is a forged cylinder, the second one a drawn and welded bottle.
Neither of these containers have been found with protective measures such as armor or wire wrapping to prevent
shattering.
- There is an automatic regulator of good design. The flow of oxygen is shut off until 10,000 feet is reached, at
which altitude an aneroid lifts the metering needle allowing oxygen to pass through the outlet.
- Japanese fighter aircraft are equipped with an oxygen generator apparatus which delivers a "continuous" flow of
oxygen. the oxygen-air mixture is automatically regulated by a diaphragn control. Bombers have an oxygen bottle
that has a "Demand" flow that opeates only when the userinhales. An automatic pilot that was examined was found to
be so similar to a type manyfactured in the United States that parts in some instances were interchangable.
The case and some of the internal parts were heavier than that used by Unites States manufacturers, but the workmanship
was good.
c. Navigation equipment
- The Japanese have good navigation equipment, for the few navigational instruments that have been captured in good condition have been
of simple but effective design, indicating much copying from other countries. An octant taken from a Japanese reconnaissance airplane
was found fairly accurate, easy to use, and painstakingly manufactured. A navigation calculator, consisting of a simple and plainly
made, celluloid disc is used.
- A Japanese drift sight, operating on a bubble gimbal system, was found easy to use, for it reduces the effect of roll and pitch.
The optical system is arranged so that the apparent motion of the image of the bubble is in the same direction as the motion of the
sight. The treatment of various parts of the sight to prevent corrotion is of good quality. The compasses that have been examined
are of conventional design, and their workmanship is good as a general rule.
d. Instruments. Japanese instruments on the whole are more or less copies of instruments used in this country several years ago.
Mass production methods were used on some of them, while on others, much hand finishing was in evidence. A more or less conventional design
was followed in the case of engine instruments, abou the only deviation being in the manifold pressure gauge which had new type of markings
on its face. Boost pressure was shown in red on the right-hand side of the dial, and negative pressure in black on the left-hand side;
zero mark, or atmospheric pressure, was the dividing line between the two colors.
e. Night fighting equipment. Night-flying equipment on the aircraft examined to date shows very little improvement over that
used in the Unitred States Air Force several years ago. no individually lighted instruments except for the pilot's compass, have been
found. Cockpits are lighted by small dashboard type lamps; some of the lamps are controlled by rheostats, while others have no
controls at all, but simply are turned on by a toggle type switch. Recent night fighter activities of the Japanese on the South Pacific
area have shown an improvement in effectiveness which may indicate an advancement in technical aspects of their equipment as well as
improved tactics.
f. Parachutes
- The Japanese use a quickly attachable seat parachute for their bomber and transport crews. Another seat type parachute is used by pilots
of fighters and other small aircraft. There have been reports that the Japanese use a chest type chute, but to date no information is
available in regard to the type of aircraft with which it is used. The construction is of circular type. Four red colored lines attached to
four of the risers extending inside the canopy to the apex (top vent), are used for "spilling" the chute.
- The material on the canopy and the shrouds is a good quality silk, and harness and pack are made of an equally quality cotton. Although
the harness is finely woven it is not as strong as those manufactured in the United States. In general, except for the advantegeous four
red shrouds mentioned above, this parachute is inferior to those made in the United States. As for the chest type parachute there is not
enough data available to date, except that the Japanese silk webbing of the harness is much less bulky than American cotton but not as
strong.
g. Photographic equipment To date very little is known about the advanced design of the Japanese photographic equipment. All of it in
good enough condition to test has been copied from equipment manufactured in the United States several years ago. Only a few minor changes
had been made, namely, the handle grip sight and in teh film magazine. Workmanship on the camera is excellent and indicated adherence to
conventional practice. On later model camera that was recovered, the cone and part of the body were made of heavy cardboard. This
specimen may have been an experimental camera, for no other similar models have been found. The film used had a nitrate base, and the
emulsion was a little slower than that used by the United Stated forces.
h. Floating gear. Flotation gear has been found in some of teh Zekes and Hamps; in both types of planes it was placed in the rear
of the fusekage. This equipment consists of a rubberized cloth bag which is held in place by eight pieces of woven cotton reinforcing tape
attached to each corner. The gear is inflatable by CO2 cylinder which is located behind the pilots seat. Evidence of flotation gear in
dive and torpedo bombers shows that it is installed in the top of the wings near the fuselage. This type air equipment is used mostly
in training and in routine flights.
i. Fuel tank protection There are three main types of Japanese fuel tank protection. The first and least effective
is called "leak absorbing". It consists of four layers of natural rubber joined together and totaling 3.1-mm (1/8 inch)
in thickness. This is covered by a kapok matting which in turn is covered by a silver fabric resembling a balloon silk The
Second type, named "leak proofing" is 12 -mm (0.47 inch) thick. It is composed mainly of heavy crude rubber in two
layers. The Third typre referred to as "self sealing", is, is 28.6-mm (1 1/8 inch) thick; It is made up of up to six
layers reinforced by an inner silken mesh and an outer galvanized iron mesh. The self sealing properties of this type
appear to be good, at least on the outer surface. A jettisonable gas tank made of wood has been examined, the length of which
is 5 fett 2 inches. The diameter 15 1/4 inches, and the capacity approximately 35 United States gallons. The construction
is of plywood panels 7/64 inch thick.
j. Fuels and lubricants. From the samples of fuel and lubricants that have been obtained, it has been found that the Japanese
fuels are good, although some contain a rather high amount of aromatics. The lubricants tested, although similar to those in the
United States , do not have some of the cold resistant properties of the latter. Samples of greases in wheels and propellors also
were found to be similar to American products.
k. Bombsights. Examination of the damaged bombsights revealed it operates on the same principle as the French bomb sights
manufactured at the begining of WWII. Stabilization of the sight is obtained via the use of a level bubble in the optical field
which is maintained in a stabilized position by hand. This sight works on a timing system and does not have electric bomb release.
Another bombsight used by the Japanese is essentially a 3 1/2 foot telescope with no stabilizing or levelling aids. The eyepiece
has no adjustment, but the sight incorporates range rate correction, and focusing.
l. bombs and torpedoes
(1) Japanese bombs in general are made of steel and usually are not streamlined. Except for the armor piercing and semiarmor
piercing bombs, they are of three piece construction, consisting of nose, body and tail. The nose and tail units are screwed in,
welded, spot welded (the point of welding is the weakest part of the bomb), or riveted to the body of the bomb.
The tail cones of some general purpose bombs are filled with explosives; in these bombs, the body and tail units are filled in
separate operations and subsequently attached. Either nose and/or tail fuses are used which are all mechanially operated. Long
delay fuses, operated by solvent disolving a celluloid screw, also has been employed, while others are operated by a slight
pyrotechnic delay.
(2) Some of the most common type bombs are antipersonnel bombs ranging from 1 to 15 kilograms (2.2 to 33 pounds); incendiaries from
1 to 250 kilograms (2.2 to 550 pounds0; and high explosives from 50 to 800 kilograms (11o to 1760 pounds). A gas bomb of 50
kilograms (110 pounds) also have been employed/ For night tactics there is a 33-kilogram (72.6 pounds) illuminating flare.
(3) The Japanese male use of 5 types of torpedoes which differ in weight, length, diameter, speed and explosive charge. Most standard
models measure 17 feet long with diameter of 17.7 inches. These torpedoes weigh 1,800 pounds and have an approximate speed of
42 knots. There exists one model which weighs 3,245 pounds, and is 22 feet long, with a diameter of 21 inches and a speed of 45 knots.
m. Sea rescue equipment A limited amount of Japanese sea rescue equiupment has been made available for examination. A 5-man
pneumatic, rubber life raft, measuring 12 feet long and 3 feet 19 inches wide, was found to be below current standards. The principal
fault was the fact that the floor is made of meshed tarred cord which does not protect the occupants against the effects of salt water.
As to sea rescue equipment for one man, a kapok life belt was examined and found to be identical with the navy kapok jacket.
A horseshoe shaped pneumatically inflated life preserver also is known to be used by the Japanese. This preserver, of single ply
construction, is weaker, but considerable lighter , than any equivalent preserver amnufactured in the United Stated. It has a good
rubber coating, but it is not designed to fit the individual. The ropes attached to the side indicate that the user hangs on to the
preserver instead of wearing it.
n. Clothing
- The Japanese Air Force received a good grade for clothing. Their flkying suits, made of good silk and cotton, are well
tailored and similar in design to the flying suits employed by the United States Army Air Forces. All items of flight
clothing recovered were sewed by skilled operators on standard machines and materials had received water and flame
proofing treatment.
- The Japanese also had an efficient, electrically heated flying suit, which, when worn as an outer garment, compares
favorably with United States electric suits. This suit, when tested, showed no hot spot when worn as an outer suit, but
it did heat up too much around the shoulders when worn under other clothes. It also had cold spots on the back of the legs
and on the inside of the arms. The fabric used is chocolate colored, and is of good quality.
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CHARACTERISTICS OF TYPICAL OPERATIONAL JAPANESE AIRCRAFT
a. General
- Markings.
Japanese aircraft markings usually consist of a large red disc on the top and bottom of the outer section of each wing
and on each side of teh fuselage. The side marking is omitted on army aircraft, but it is retained on Navy aircraft.
Occasionally the red disc is surrounded by a narrow white line.
On biplane wing markings appear only on the top of the upper wing and the bottom of the lower wing. Individual squadron
markings may be found on the fin and rudder.
- Designation types.
Tables on this website present the main characteristics of Japanese aircraft believed to be operational as of September
1944 (See figure 76.) Types now in the experimental stage meay become operational soon, marking some current types
obsolecent. Under the Japanese system of airplane designation, the type number indicates the year in which the aircraft
was adopted. Type 97 corresponds to the Japanese year2597 (our year 1937). For this reason, various categorioes of
aircraft-fighters, bombers, reconnaissance and others - all may be designated, for example, as type 0. Modifications and
variations are given different model numbers such as Model 11, Model 21, Model 22. The Japanese airplanes, developed
since their new coding system went into effect, have Model 11 as the designation of the first model. This indicates that
it is the first airframe and the first engine. A change in the airframe, including the addition of armament or armor, is
shown by a change in the first digit, for example, Model 21; and an engine change by a new second digit, for ezample,
Model 12. If both airframe and engine are replaced, the model would be 22.
Each additional change is shown in this manner;
For exmaple, Zeke Type 0 carrier borne fighter with models 11,21,22,32 and 52. New Navy airplanes are being given symbolic
names such as winds, stars, mountain, etc. In place of the Type numbers; that is, Judy 11 is
"Suisei" (Comet) Model 11. Army planes have a single model number which is changed with
each modification.
- Allied identification or code names. in order to eliminate the confusion regarding the designations
of Japanese aircraft a code name is assigned to each plane by the Akllied air agencies. Army and Navy fighters
and Navy reconnaissance planes, and flying boats have feminine names such as Betty, Dinah, and Emily. Transports
are assigned names begining with the letter T as Topsy, Tess, Thelma.
existance of a new type is confrmed a new code name is assigned. The code name is established on the basis
of the primary function of the plane in cases where dual purposes may exist. The model number follows the
code name for more specific identification; for example, Zeke 11 , Zeke 22.
b. Fighters
- General. As of 1944, there are approximately ten operational first-line fighters
of the Army and Navy, with several types now obsolescent which may be encountered in some areas and several new
types not yet operational but believed ready to go into production.
- Representative operational Navy fighters.
(a) Zeke 52. This is a single engine, low wing monoplane very much like the Douglas Dauntless
(A-24 or SBD) with impered wings, round nose, cockpit set high on the fuselage. The Zeke 52 and its
predecessors, the Zeke 21 and 32 (Hamp), are the most familiar carrier borne fighters. It may be
be replaced soon by Sam 11, not yet met operationally,
(b) Irving 11. Primarily a night fighter. This is a twin engine, low wing monoplane with the
engine necelles projecting far forward of the wings. It carries a crew of two, and in addition to five
20-mm guns is capable of carrying two 550-pound bombs. It is radar equipped.
- Representative Army fighters.
(a) Oscar 2. This airplane has a distinctive straight leading edge on the wings with a tapered
trailing edge. It is a single engine, low wing monoplane, highly maneuverable and with a high rate of
climb. Every theater patrolled by the Japanese Army Air Force has had operational Oscars.
(b) Nick 1. This is a heavy twin engine fighter, two place, with low wing, long tapered fuselage,
and tall fin and rudder. A 37-mm cannon mounted on the underside indicates use for ground strafing and
anti-tank operation.
c. Torpedo Dive and Light bombers
- General. With approach from the sea the greatest threat to the homeland,
Japanese aircraft designed to combat shipping has been given more attention recently. Japanese so
called light bombers are dive-break equipped for wider use.
- Representative Navy types.
(a) Grace 11. Designated as a torpedo bomber, Grace is equipped also to carry bombs, making this
an all purpose bomber. It is a single engine airplane with an inverted gull mid wing.
(b) Frances 11. One of the newer all purpose bombers for both torpedo and dive bombing, frances
is a twin engine, mid-wing monoplane, with pointed spinners far forward, and a narrow fuselage. The span
is 65' 6", the greates in this class.
- Representative Army types. Lily 2. Equipped with dive brakes, this new model of Lily becomes
an all purpose bomber, the only operational army airctaft in this classification. It is a twin engine,
mid-wing monoplane with engine nacelles extending to the trailing edge of the wing. Lily is
reportedly fast and hard to catch in level flight.
d. Bombers
- General. Japanese bombers are the equivalent of U.S. medium bombers. Twin engine
types are the largest in operation. Newer models have greater protection for crews and fuel tanks in
addition to increased bomb loadcapacity.
- Representative Navy bombers.
Betty 22. This is a twin engine, mid-wing monoplane with a cigar shaped fuselage. Nose and tail
are transparent and equipped with guns. There have been several models of Betty. The latest reportedly
"completly bullet proofed". Betty is used for reconnaissance and torpedo bombing as well as level bombing.
- Representative Army bombers.
(a) Helen 2. Rated exceptionmally efficient by the Japanese , Helen has been operational in all
theaters. It is a twin engine, mid-wing monoplane, with a long canopy which has a transparent pilot's
cockpit in the front and transparent gunner's seat in the rear. There is a tail turret under the single
fin and rudder.
(b) Peggy 1. Little was known about this airplane in 1944. It was the newest Japanese Army
Air Force bomber. Reportedly it is well armored, with high fire power, high cruising speed, and a bomb
load capacity of at least two tons.
e. Reconnaissance
- General. The Japanese have developed a variety of reconnaissance planes. Some
originally designated for reconnaissance have been used for light bombing or as torpedo bombers. Most
reconnaissance planes are capable of carrying bombs or torpedoes to supplement their rocon duties.
- Representative Navy types.
(a) Pete 11. This biplane, with its single main float, is familiar in all Pacific thaters. It has
been the principal short range observation plane.
(b) Myrt 11. Myrt is an exceptionally high speed, lomg range, carrier based reconnaissance plane
capable of carrying one 1765 pound torpedoin addition to cameras. It is a single engine, low wing monoplane
with a long cockpit enclosure.
- Representative Army types.
(a) Sonia 1 "A". The reconnaissance version of Sonia is used for ground cooperation and has
cameras mounted . The assault version is similar. Sonia is a single engine, low wing monoplane with
the wing flat under the fuselage and teh dihadral starting at the stubs of the wings. The long raised
cockpit is open at the rear and the landing gear is not retractable.
(b) Dinah 3. As a rule this airplane has had no armamant and the armor is ineffective. It has large
fuel tanks for its size and should burn very easily. Dinah is twin engine with low-wing, fore and aft
cockpit.
f. Flying boats
- General.
There are three operational flying boats, Mavis and Emily, with four engines and Cherry with two. Mavis and Emily have proved
themselves to the extent that several models have been operational.
- Navy types.
(a) Mavis II. This is a four-engine flying boat with a high parasol wing, twin fins and rudders, and a single hull. It is
armed for protection forward, rear, top, and side and is capable of carrying nombs or topedoes. Mavis has been operational
in all Pacific theaters.
(b) Emily 12. Emily has the best fuel tank protection of any Japanese aircraft yet examined and the armor for the
protection of the pilot is good. This is a four-engine , high wing, single hull aircraft with single high fin and rudder.
It is comparatively welll armed and has a small bomb or torpedoe capacity. Its long range and high performance make Emily
useful in both reconnaissance and bombing roles.
(c) Cerry 11. The pronounce swee-up to the tail and the twin engines distinguish Cherry from other flying boats. It has a
high wing and twin fin rudders. Cherry is obsolecent but may still be encountered operationally.
g. Transports
- General.
Japanese transports have been given Allied code names which are feminine and begin with the letter T. The exception is
four engine Liz which originally was designed as a heavy bomber but proved unsatisfactory and now is used as a transport.
The regular transports are adaptations of commercial aircrtaft, all of which are twin-engine. Navy Tess and Tabby are
Japanese versions of the Douglas DC-2 and DC=3. Army Thelma was orifinally the Lockheed 14 (Loadstar).
- Other Navy types.
Liz II. This is the four-engine airplane converted from its original design as a long range bomber. It is a low mid-wing
monoplane with a high tail, twin fins and rudders, long nose and tricicle landing gear.
- Other Army types.
(a) Topsy 2. This is the military version of a Japanese transport MC-20 which was extensively used before
the war. It is a twin-engine, low-wing monoplane. The wings are sharply tapered and the cockpit is forward of the
leading edge of the wing. The freight capacity is 2 1/4 tons.
(b) Thora 2.
Thora was evolved from Japanese commercial aircraft. It is a twin engine, low wing
monoplane. The leading edge of the wing is sharply tapered and the trailing edge only slightly tapered.
JAPANESE AIRCRAFT SILHOUTTES
JAPANESE AIRCRAFT PICTURES