A6M Zero
Encyclopedia
The Mitsubishi A6M Zero was a long-range fighter aircraft
operated by the Imperial Japanese Navy Air Service
(IJNAS) from 1940 to 1945. The A6M was designated as the , and also designated as the Mitsubishi A6M Rei-sen and Mitsubishi Navy 12-shi Carrier Fighter. The A6M was usually referred to by the Allies
as the
"Zero", from the 'Navy Type 0 Carrier Fighter' designation. The official Allied reporting name
was Zeke.
When it was introduced early in World War II
, the Zero was considered the most capable carrier-based fighter in the world, combining excellent maneuverability and very long range. In early combat operations, the Zero gained a legendary reputation as a "dogfighter", achieving the outstanding kill ratio of 12 to 1, but by mid-1942 a combination of new tactics and the introduction of better equipment enabled the Allied pilots to engage the Zero on more equal terms. The IJNAS also frequently used the type as a land-based fighter. By 1943, inherent design weaknesses and the increasing lack of more powerful aircraft engine
s meant that the Zero became less effective against newer enemy fighters that possessed greater firepower, armor, and speed, and approached the Zero's maneuverability. Although the Mitsubishi A6M was outdated by 1944, it was never totally supplanted by the newer Japanese aircraft types. During the final years of the War in the Pacific
, the Zero was used in kamikaze
operations. In the course of the war, more Zeros were built than any other Japanese aircraft.
The Mitsubishi A5M
fighter was just entering service in early 1937, when the Imperial Japanese Navy
started looking for its eventual replacement. In May they issued specification 12-Shi for a new carrier-based fighter, sending it to Nakajima
and Mitsubishi
. Both firms started preliminary design work while they awaited more definitive requirements to be handed over in a few months.
Based on the experiences of the A5M in China, the Navy sent out updated requirements in October calling for a speed of 500 km/h (310 mph) at 4,000 m (13,120 ft) and a climb to 3,000 m (9,840 ft) in 3.5 min. With drop tanks, they wanted an endurance of two hours at normal power, or six to eight hours at economical cruising speed. Armament was to consist of two 20 mm cannon
, two 7.7 mm (.303 in) machine gun
s and two 30 kg (70 lb) or 60 kg (130 lb) bomb
s. A complete radio set was to be mounted in all aircraft, along with a radio direction finder
for long-range navigation. The maneuverability was to be at least equal to that of the A5M, while the wing span had to be less than 12 m (39 ft) to allow for use on aircraft carriers. All this was to be achieved with available engines, a significant design limitation. (The Zero's power plant seldom reached 1000 hp in any of its variants).
Nakajima's team considered the new requirements unachievable and pulled out of the competition in January. Mitsubishi's chief designer, Jiro Horikoshi
, felt that the requirements could be met, but only if the aircraft could be made as light as possible. Every possible weight-saving measure was incorporated into the design. Most of the aircraft was built of a new top-secret 7075 aluminium alloy developed by Sumitomo Metal Industries
in 1936. Called Extra Super Duralumin
(ESD), it was lighter and stronger than other alloys (e.g. 24S alloy) used at the time, but was more brittle and prone to corrosion (it was painted with an anti-corrosion lacquer as a countermeasure). No armor was provided for the pilot, engine or other critical points of the aircraft, and self-sealing fuel tank
s, which were becoming common at the time, were not used. This made the Zero lighter and more agile than most other aircraft at the start of the war, but also made it prone to catching fire and exploding when struck by enemy rounds.
With its low-wing cantilever
monoplane
layout, retractable, wide-set landing gear
and enclosed cockpit, the Zero was one of the most modern aircraft in the world at the time of its introduction. It had a fairly high-lift, low-speed wing with a very low wing loading
. This, combined with its light weight, resulted it a very low stalling speed
of well below 60 kn (117.6 km/h; 73.1 mph). This was the main reason for its phenomenal maneuverability, allowing it to out-turn any Allied fighter of the time. Early models were fitted with servo tab
s on the aileron
s after pilots complained control forces became too heavy at speeds above 300 km/hr. They were discontinued on later models after it was found that the lightened control forces were causing pilots to overstress the wings during vigorous maneuvers. At 160 mph (260 km/h) the A6M2 had a roll rate of 56° per second. Because of wing flexibility, roll effectiveness dropped to near zero at about 483 km/h (300.1 mph) indicated airspeed.
It has been claimed that the Zero's design showed clear influence from American fighter planes and components exported to Japan in the 1930s, and in particular the Vought V-143
fighter. Chance Vought
had sold the prototype for this aircraft and its plans to Japan in 1937. Eugene Wilson, President of Vought, claimed that when shown a captured Zero in 1943, he found that "There on the floor was the Vought V 142 [sic] or just the spitting image of it, Japanese-made," while the "power-plant installation was distinctly Chance Vought, the wheel stowage into the wing roots came from Northrop, and the Japanese designers had even copied the Navy inspection stamp from Pratt & Whitney type parts." While the sale of the V-143 was fully legal, Wilson later acknowledged the conflicts of interest that can arise whenever military technology is exported. In fact, there was no significant relationship between the V-143 (which was an unsuccessful design that had been rejected by the US Army Air Corps and several export customers) and the Zero, with only a superficial similarity in layout. Allegations about the Zero being a copy have been mostly discredited.
, Type 0 Carrier Fighter (Rei shiki Kanjō sentōki, 零式艦上戦闘機), taken from the last digit of the Imperial year 2600 (1940), when it entered service. In Japan it was unofficially referred to as both Rei-sen and Zero-sen; Japanese pilots most commonly called it, Zero-sen.
In the official designation "A6M" the "A" signified a carrier-based
fighter, "6" meant it was sixth such model built for the Imperial Navy, and "M" indicated the manufacturer, Mitsubishi
.
The official Allied code name was "Zeke", in keeping with the practice of giving male names to Japanese fighters, female names to bomber
s, bird names to glider
s, and tree names to trainer
s. "Zeke" was part of the first batch of "hillbilly" code names assigned by Captain Frank T. McCoy of Tennessee, who wanted quick, distinctive, easy to remember names. When in 1942 the Allied code for Japanese aircraft was introduced, he logically chose "Zeke" for the "Zero." Later, two variants of the fighter received their own code names: the A6M2-N (floatplane
version of the Zero) was called Rufe and the A6M3-32 variant was initially called Hap. After objections from General "Hap" Arnold
, commander of the USAAF, the name was changed to Hamp.
The first Zeros (pre-series A6M2) went into operation in July 1940. On 13 September 1940, the Zeros scored their first air-to-air victories when 13 A6M2s led by Lieutenant Saburo Shindo attacked 27 Soviet-built Polikarpov I-15
s and I-16s of the Chinese Nationalist Air Force, shooting down all the fighters without loss to themselves. By the time they were redeployed a year later, the Zeros had shot down 99 Chinese aircraft (266 according to other sources).
At the time of the [attack on Pearl Harbor]] 420 Zeros were active in the Pacific. The carrier-borne Model 21 was the type encountered by the Americans. Its tremendous range of over 2,600 km (1,600 mi) allowed it to range further from its carrier than expected, appearing over distant battlefronts and giving Allied commanders the impression that there were several times as many Zeros as actually existed.
The Zero quickly gained a fearsome reputation. Thanks to a combination of excellent maneuverability and firepower, it easily disposed of the motley collection of Allied aircraft sent against it in the Pacific in 1941. It proved a difficult opponent even for the Supermarine Spitfire
. Although not as fast as the British fighter, the Mitsubishi fighter could out-turn the Spitfire with ease, could sustain a climb at a very steep angle, and could stay in the air for three times as long.
Soon, however, Allied pilots developed tactics to cope with the Zero. Due to its extreme agility, engaging in a traditional, turning dogfight with a Zero was likely to be fatal. It was better to roar down from above in a high-speed pass, fire a quick burst, then zoom back up to altitude. (A short burst of fire from heavy machine guns or cannon was often enough to bring down the fragile Zero.) Such "boom-and-zoom" tactics were used successfully in the China Burma India Theater
(CBI) by the "Flying Tigers
" of the American Volunteer Group (AVG) against similarly maneuverable Japanese Army aircraft such as the Nakajima Ki-27
and Ki-43
. AVG pilots were trained to exploit the advantages of their P-40s
, which were very sturdy, heavily armed, generally faster in a dive and level flight at low altitude, with a good rate of roll.
Another important maneuver was Lieutenant Commander John S. "Jimmy" Thach's "Thach Weave
", in which two fighters would fly about 60 m (200 ft) apart. If a Zero latched onto the tail of one of the fighters, the two aircraft would turn toward each other. If the Zero followed his original target through the turn, he would come into a position to be fired on by the target's wingman. This tactic was first used to good effect during the Battle of Midway, and later over the Solomon Islands
. Many highly experienced Japanese aviators were lost in combat, resulting in a progressive decline in the quality of the opponents faced by Allied pilots, which became a significant factor in Allied successes. Unexpected heavy losses of these irreplaceable pilots at the battles of the Coral Sea and Midway
dealt the Japanese carrier air force a blow from which it never fully recovered.
In contrast, Allied fighters were designed with ruggedness and pilot protection in mind. The Japanese ace Saburo Sakai described how the resilience of early Grumman aircraft was a factor in preventing the Zero from attaining total domination:
When the powerful Lockheed P-38 Lightning, Grumman F6F Hellcat, and Vought F4U Corsair appeared in the Pacific theater, the A6M, with its low-powered engine, was hard-pressed to remain competitive. In combat with an F6F or F4U, the only positive thing that could be said of the Zero at this stage of the war was that in the hands of a skillful pilot it could maneuver as well as most of its opponents. Nonetheless, in competent hands the Zero could still be deadly.
Due to shortages of high-powered aviation engines and problems with planned successor models, the Zero remained in production until 1945, with over 11,000 of all variants produced. It is said that Zeros destroyed at least 1,550 American aircraft during the course of the war.
in the Aleutians (which was called the Akutan Zero
). During an air raid over Dutch Harbor on 4 June 1942, one A6M fighter was hit by ground fire. Losing oil, Flight Petty Officer Tadayoshi Koga attempted an emergency landing on Akutan Island about 20 miles northeast of Dutch Harbor, but his Zero flipped over in soft ground in a sudden crash landing. Koga died instantly of head injuries, but the relatively undamaged fighter was found over a month later by an American salvage team and shipped to Naval Air Station North Island
where testing flights of the repaired A6M revealed not only its strengths, but also its deficiencies in design and performance.
The experts who evaluated the captured Zero found that the plane weighed 5,200 pounds fully loaded, half the weight of the standard United States Navy fighter. It was "built like a fine watch"; the Zero was constructed with flush rivets, and even the guns were flush with the wings. The instrument panel was a "marvel of simplicity ... with no superfluities to distract [the pilot]." What most impressed the experts was that the Zero's fuselage and wings were constructed in one piece, unlike the American method that built them separately and joined the two parts together. The Japanese method was much slower, but resulted in a very strong structure and improved close manuverability.
Captain Eric Brown, the Chief Naval Test Pilot of the Royal Navy, recalled being impressed by the Zero during tests of captured aircraft. "I don’t think I have ever flown a fighter that could match the rate of turn of the Zero. The Zero had ruled the roost totally and was the finest fighter in the world until mid-1943." American test pilots found that the Zero's controls were "very light" at 200 miles per hour, but stiffened at faster speeds. While stable on the ground despite its light weight, the aircraft was designed purely for the attack role, emphasizing long range, maneuverability, and firepower at the expense of protection of its pilot. Most had neither self-sealing tanks nor armor plating.
A6M1, Type 0 Prototypes
The first A6M1 prototype was completed in March 1939, powered by the 580 kW (780 hp) Mitsubishi Zuisei
13 engine with a two-blade propeller. It first flew on 1 April, and passed testing in a remarkably short period of time. By September, it had already been accepted for Navy testing as the A6M1 Type 0 Carrier Fighter, with the only notable change being a switch to a three-bladed propeller to cure a vibration problem.
12 engine instead. Mitsubishi had its own engine of this class in the form of the Kinsei
, so they were somewhat reluctant to use the Sakae. Nevertheless, when the first A6M2 was completed in January 1940, the Sakae's extra power pushed the performance of the Zero well past the original specifications.
The new version was so promising that the Navy had 15 built and shipped to China before they had completed testing. They arrived in Manchuria
in July 1940, and first saw combat over Chungking in August. There they proved to be completely untouchable by the Polikarpov I-16
s and I-153
s that had been such a problem for the A5Ms currently in service. In one encounter, 13 Zeros shot down 27 I-15s and I-16s in under three minutes without loss. After hearing of these reports the Navy immediately ordered the A6M2 into production as the Type 0 Carrier Fighter, Model 11.
Reports of the Zero's performance filtered back to the US slowly. There they were dismissed by most military officials, who felt it was impossible for the Japanese to build such an aircraft.
After the delivery of only 65 aircraft by November 1940, a further change was worked into the production lines, which introduced folding wingtips to allow them to fit on aircraft carrier
s. The resulting Model 21 would become one of the most produced versions early in the war. When the lines switched to updated models, 740 Model 21s had been completed by Mitsubishi, and another 800 by Nakajima. Two other versions of the Model 21 were built in small numbers, the Nakajima-built A6M2-N "Rufe" floatplane
(based on the Model 11 with a slightly modified tail), and the A6M2-K two-seat trainer of which a total of 508 were built by Hitachi and the Sasebo Naval Air Arsenal.
In late 1941, Nakajima introduced the Sakae 21, which used a two-speed supercharger
for better altitude performance, and increased power to 840 kW (1,130 hp). Plans were made to introduce the new engine into the Zero as soon as possible.
The new Sakae was slightly heavier and somewhat longer due to the larger supercharger, which moved the center of gravity
too far forward on the existing airframe. To correct for this the engine mountings were cut down by 20 cm (8 in), moving the engine back towards the cockpit. This had the side effect of reducing the size of the main fuel tank (located to the rear of the engine) from 518 L (137 US gal) to 470 L (120 US gal).
The only other major changes were to the wings, which were simplified by removing the Model 21's folding tips. This changed the appearance enough to prompt the US to designate it with a new code name, Hap. This name was short-lived, as a protest from USAAF commander General Henry "Hap" Arnold
forced a change to "Hamp". Soon after, it was realized that it was simply a new model of the "Zeke". The wings also included larger ammunition boxes, allowing for 100 rounds for each of the 20 mm cannon.
The wing changes had much greater effects on performance than expected. The smaller size led to better roll, and their lower drag allowed the diving speed to be increased to 670 km/h (420 mph). On the downside, maneuverability was reduced, and range suffered due to both decreased lift and the smaller fuel tank. Pilots complained about both. The shorter range proved a significant limitation during the Solomons campaign of 1942.
The first Model 32 deliveries began in April 1942, but it remained on the lines only for a short time, with a run of 343 being built.
As the airframe was reverted from the Model 32 and the engine remained the same, this version received the navy designation Model 22, while Mitsubishi called it the A6M3a. The new model started production in December, and 560 were eventually produced. This company constructed some examples for evaluation, armed with 30 mm Type 5 Cannon, under denomination of A6M3b (model 22b).
A few late-production A6M3 Model 22s had a wing similar to the later shortened, rounded tip wing fitted to the A6M5 Model 52. These were probably a transition model, at least one was photographed at Rabaul-East in Mid-1943.
Considered the most effective variant, the Model 52 was developed to face the powerful American F6F Hellcat
and F4U Corsair
, superior mostly for engine power and armament. The variant was a modest update of the A6M3 Model 22, with non-folding wing tips and thicker wing skinning to permit faster diving speeds, plus an improved exhaust system. The latter used four ejector exhaust stacks, providing an increment of thrust, projecting along each side of the forward fuselage. The new exhaust system required modified "notched" cowl flaps and small rectangular plates which were riveted to the fuselage, just aft of the exhausts. Two smaller exhaust stacks exited via small cowling
flaps immediately forward of and just below each of the wing leading edges. The improved roll-rate of the clipped-wing A6M3 was now built in.
Sub-variants included:
The A6M5 had a maximum speed of 540 km/h (340 mph) and reached a height of 8,000 m (26,250 ft) in nine minutes, 57 seconds. Other variants were the night fighter
A6M5d-S (modified for night combat, armed with one 20 mm Type 99 cannon, inclined back to the pilot's cockpit) and A6M5-K "Zero-Reisen"(model l22) tandem trainer
version, also manufactured by Mitsubishi.
62 engine with 1,560 hp (1,164 kW), 60% more powerful than the engine of the A6M2. This resulted in an extensively modified cowling and nose for the aircraft. The carburetor intake was much larger, a long duct like that on the Nakajima B6N Tenzan was added, and a large spinner—like that on the Yokosuka D4Y Suisei with the Kinsei 62—was mounted. The larger cowling meant deletion of the fuselage mounted machine gun, but armament was otherwise unchanged from the Model 52 Hei (20 mm cannon x 2; 13 mm/.51 in MG x 2). In addition, the Model 64 was modified to carry two 150 L (40 US gal) drop tanks on either wing in order to permit the mounting of a 250 kg (550 lb) bomb on the underside of the fuselage. Two prototypes were completed in April 1945 but the chaotic situation of Japanese industry and the end of the war obstructed the start of the ambitious program of production for 6,300 machines, none being completed.
Thailand
Several Zero fighters survived the war and are on display in Japan (in Aichi, Tokyo's Yasukuni War Museum, Hiroshima, Hamamatsu, MCAS Iwakuni, and Shizuoka), China (in Beijing), United States (at the National Air and Space Museum
, National Museum of the United States Air Force
, the National Museum of Naval Aviation
, the Pacific Aviation Museum
, the San Diego Air and Space Museum), and the UK (Duxford) as well as the Auckland War Memorial Museum in New Zealand. A restored A6M2-21 (V-173 retrieved as a wreck after the war, and later found to have been flown by Saburō Sakai
at Lae
) is on display at the Australian War Memorial
in Canberra.
Another aircraft recovered by the Australian War Memorial Museum in the early 1970s now belongs to Fantasy of Flight
in Polk City, Florida. Along with several other Zeros it was found near Rabaul in the South Pacific. The markings suggest that it was in service after June 1943 and further investigation suggests that it has cockpit features conducive to the Nakashima built model 52b. If this is correct, it is most likely one of the 123 aircraft lost by the Japanese during the assault of Rabaul. The aircraft was shipped in pieces to the attraction and it was eventually made up for display as a crashed aircraft. Much of the aircraft is usable for patterns and some of its parts can be restored to one day make this a basis for a flyable aircraft.
A number of flyable Zero airframes exist; most have had their engines replaced with similar American units; only one, the Planes of Fame Museum's A6M5 example, bearing tail number "61-120" has the original Sakae engine, as seen in a flight demonstration video of this aircraft.
Although not truly a survivor, the "Blayd" Zero is a reconstruction based on templating original Zero components recovered from the South Pacific. In order to be considered a "restoration," the builders used a small fraction of parts from original Zero landing gear in the reconstruction. The aircraft is now on display at the Fargo Air Museum
in Fargo, North Dakota.
The rarity of flyable Zeros accounts for the use of single-seat North American T-6 Texan
s, modified externally and painted in Japanese markings, to stand in for the fighter in the films Tora! Tora! Tora!
, The Final Countdown, and many other television and film depictions of the aircraft, such as Baa Baa Black Sheep
(renamed Black Sheep Squadron). One Model 52 was used during the production of Pearl Harbor
.
Video links
Fighter aircraft
A fighter aircraft is a military aircraft designed primarily for air-to-air combat with other aircraft, as opposed to a bomber, which is designed primarily to attack ground targets...
operated by the Imperial Japanese Navy Air Service
Imperial Japanese Navy Air Service
The Imperial Japanese Navy Air Service was the air arm of the Imperial Japanese Navy during World War II, the organization was responsible for the operation of naval aircraft and the conduct of aerial warfare in the Pacific War.It was controlled by the Navy Staff of the Imperial Japanese Navy and...
(IJNAS) from 1940 to 1945. The A6M was designated as the , and also designated as the Mitsubishi A6M Rei-sen and Mitsubishi Navy 12-shi Carrier Fighter. The A6M was usually referred to by the Allies
Allies of World War II
The Allies of World War II were the countries that opposed the Axis powers during the Second World War . Former Axis states contributing to the Allied victory are not considered Allied states...
as the
"Zero", from the 'Navy Type 0 Carrier Fighter' designation. The official Allied reporting name
World War II Allied names for Japanese aircraft
The World War II Allied names for Japanese aircraft were reporting names, often described as codenames, given by Allied personnel to Imperial Japanese aircraft during the Pacific campaign of World War II. The names were used by Allied personnel to identify Japanese aircraft for reporting and...
was Zeke.
When it was introduced early in World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, the Zero was considered the most capable carrier-based fighter in the world, combining excellent maneuverability and very long range. In early combat operations, the Zero gained a legendary reputation as a "dogfighter", achieving the outstanding kill ratio of 12 to 1, but by mid-1942 a combination of new tactics and the introduction of better equipment enabled the Allied pilots to engage the Zero on more equal terms. The IJNAS also frequently used the type as a land-based fighter. By 1943, inherent design weaknesses and the increasing lack of more powerful aircraft engine
Aircraft engine
An aircraft engine is the component of the propulsion system for an aircraft that generates mechanical power. Aircraft engines are almost always either lightweight piston engines or gas turbines...
s meant that the Zero became less effective against newer enemy fighters that possessed greater firepower, armor, and speed, and approached the Zero's maneuverability. Although the Mitsubishi A6M was outdated by 1944, it was never totally supplanted by the newer Japanese aircraft types. During the final years of the War in the Pacific
Pacific Ocean theater of World War II
The Pacific Ocean theatre was one of four major naval theatres of war of World War II, which pitted the forces of Japan against those of the United States, the British Commonwealth, the Netherlands and France....
, the Zero was used in kamikaze
Kamikaze
The were suicide attacks by military aviators from the Empire of Japan against Allied naval vessels in the closing stages of the Pacific campaign of World War II, designed to destroy as many warships as possible....
operations. In the course of the war, more Zeros were built than any other Japanese aircraft.
Design and development
Mitsubishi A5M
The Mitsubishi A5M, Japanese Navy designation was "Type 96 carrier-based fighter" was a Japanese carrier-based fighter aircraft. It was the world's first monoplane shipboard fighter and the direct ancestor of the famous Mitsubishi A6M 'Zero'...
fighter was just entering service in early 1937, when the Imperial Japanese Navy
Imperial Japanese Navy
The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...
started looking for its eventual replacement. In May they issued specification 12-Shi for a new carrier-based fighter, sending it to Nakajima
Nakajima Aircraft Company
The Nakajima Aircraft Company was a prominent Japanese aircraft manufacturer throughout World War II.-History:...
and Mitsubishi
Mitsubishi
The Mitsubishi Group , Mitsubishi Group of Companies, or Mitsubishi Companies is a Japanese multinational conglomerate company that consists of a range of autonomous businesses which share the Mitsubishi brand, trademark and legacy...
. Both firms started preliminary design work while they awaited more definitive requirements to be handed over in a few months.
Based on the experiences of the A5M in China, the Navy sent out updated requirements in October calling for a speed of 500 km/h (310 mph) at 4,000 m (13,120 ft) and a climb to 3,000 m (9,840 ft) in 3.5 min. With drop tanks, they wanted an endurance of two hours at normal power, or six to eight hours at economical cruising speed. Armament was to consist of two 20 mm cannon
Cannon
A cannon is any piece of artillery that uses gunpowder or other usually explosive-based propellents to launch a projectile. Cannon vary in caliber, range, mobility, rate of fire, angle of fire, and firepower; different forms of cannon combine and balance these attributes in varying degrees,...
, two 7.7 mm (.303 in) machine gun
Machine gun
A machine gun is a fully automatic mounted or portable firearm, usually designed to fire rounds in quick succession from an ammunition belt or large-capacity magazine, typically at a rate of several hundred rounds per minute....
s and two 30 kg (70 lb) or 60 kg (130 lb) bomb
Bomb
A bomb is any of a range of explosive weapons that only rely on the exothermic reaction of an explosive material to provide an extremely sudden and violent release of energy...
s. A complete radio set was to be mounted in all aircraft, along with a radio direction finder
Radio direction finder
A radio direction finder is a device for finding the direction to a radio source. Due to low frequency propagation characteristic to travel very long distances and "over the horizon", it makes a particularly good navigation system for ships, small boats, and aircraft that might be some distance...
for long-range navigation. The maneuverability was to be at least equal to that of the A5M, while the wing span had to be less than 12 m (39 ft) to allow for use on aircraft carriers. All this was to be achieved with available engines, a significant design limitation. (The Zero's power plant seldom reached 1000 hp in any of its variants).
Nakajima's team considered the new requirements unachievable and pulled out of the competition in January. Mitsubishi's chief designer, Jiro Horikoshi
Jiro Horikoshi
was the chief engineer behind many Japanese fighters of WWII. Most notable of such was the Mitsubishi A6M Zero fighter.He was born near the city of Fujioka, Gunma Prefecture, Japan....
, felt that the requirements could be met, but only if the aircraft could be made as light as possible. Every possible weight-saving measure was incorporated into the design. Most of the aircraft was built of a new top-secret 7075 aluminium alloy developed by Sumitomo Metal Industries
Sumitomo Metal Industries
is a company with seat in Osaka, Japan. )It is the third largest integrated steel manufacturer in Japan withthree integrated steelworks and several other manufacturing plants.It is one of the largest manufacturers of Seamless Pipes and Tubes,...
in 1936. Called Extra Super Duralumin
Duralumin
Duralumin is the trade name of one of the earliest types of age-hardenable aluminium alloys. The main alloying constituents are copper, manganese, and magnesium. A commonly used modern equivalent of this alloy type is AA2024, which contains 4.4% copper, 1.5% magnesium, 0.6% manganese and 93.5%...
(ESD), it was lighter and stronger than other alloys (e.g. 24S alloy) used at the time, but was more brittle and prone to corrosion (it was painted with an anti-corrosion lacquer as a countermeasure). No armor was provided for the pilot, engine or other critical points of the aircraft, and self-sealing fuel tank
Self-sealing fuel tank
In aviation, self-sealing fuel tank is a fuel tank technology in wide use since World War II that prevents fuel tanks primarily on aircraft from leaking fuel and igniting after being damaged by enemy fire....
s, which were becoming common at the time, were not used. This made the Zero lighter and more agile than most other aircraft at the start of the war, but also made it prone to catching fire and exploding when struck by enemy rounds.
With its low-wing cantilever
Cantilever
A cantilever is a beam anchored at only one end. The beam carries the load to the support where it is resisted by moment and shear stress. Cantilever construction allows for overhanging structures without external bracing. Cantilevers can also be constructed with trusses or slabs.This is in...
monoplane
Monoplane
A monoplane is a fixed-wing aircraft with one main set of wing surfaces, in contrast to a biplane or triplane. Since the late 1930s it has been the most common form for a fixed wing aircraft.-Types of monoplane:...
layout, retractable, wide-set landing gear
Undercarriage
The undercarriage or landing gear in aviation, is the structure that supports an aircraft on the ground and allows it to taxi, takeoff and land...
and enclosed cockpit, the Zero was one of the most modern aircraft in the world at the time of its introduction. It had a fairly high-lift, low-speed wing with a very low wing loading
Wing loading
In aerodynamics, wing loading is the loaded weight of the aircraft divided by the area of the wing. The faster an aircraft flies, the more lift is produced by each unit area of wing, so a smaller wing can carry the same weight in level flight, operating at a higher wing loading. Correspondingly,...
. This, combined with its light weight, resulted it a very low stalling speed
Stall (flight)
In fluid dynamics, a stall is a reduction in the lift coefficient generated by a foil as angle of attack increases. This occurs when the critical angle of attack of the foil is exceeded...
of well below 60 kn (117.6 km/h; 73.1 mph). This was the main reason for its phenomenal maneuverability, allowing it to out-turn any Allied fighter of the time. Early models were fitted with servo tab
Servo tab
A servo tab is a small hinged device installed on an aircraft control surface to assist the movement of the control surface.-Servo tabs:...
s on the aileron
Aileron
Ailerons are hinged flight control surfaces attached to the trailing edge of the wing of a fixed-wing aircraft. The ailerons are used to control the aircraft in roll, which results in a change in heading due to the tilting of the lift vector...
s after pilots complained control forces became too heavy at speeds above 300 km/hr. They were discontinued on later models after it was found that the lightened control forces were causing pilots to overstress the wings during vigorous maneuvers. At 160 mph (260 km/h) the A6M2 had a roll rate of 56° per second. Because of wing flexibility, roll effectiveness dropped to near zero at about 483 km/h (300.1 mph) indicated airspeed.
It has been claimed that the Zero's design showed clear influence from American fighter planes and components exported to Japan in the 1930s, and in particular the Vought V-143
Vought V-141
-References:* Angelucci, Enzo and Peter M. Bowers. The American Fighter. Sparkford, UK: Haynes Publishing, 1987. ISBN 0-85429-635-2.*Francillon, R.J. Japanese Aircraft of the Pacific War . London: Putnam, 1970. ISBN 0 370 00033 1....
fighter. Chance Vought
Vought
Vought is the name of several related aerospace firms. These have included, in the past, Lewis and Vought Corporation, Chance Vought, Vought Sikorsky, LTV Aerospace , Vought Aircraft Companies, and the current Vought Aircraft Industries. The first incarnation of Vought was established by Chance M...
had sold the prototype for this aircraft and its plans to Japan in 1937. Eugene Wilson, President of Vought, claimed that when shown a captured Zero in 1943, he found that "There on the floor was the Vought V 142 [sic] or just the spitting image of it, Japanese-made," while the "power-plant installation was distinctly Chance Vought, the wheel stowage into the wing roots came from Northrop, and the Japanese designers had even copied the Navy inspection stamp from Pratt & Whitney type parts." While the sale of the V-143 was fully legal, Wilson later acknowledged the conflicts of interest that can arise whenever military technology is exported. In fact, there was no significant relationship between the V-143 (which was an unsuccessful design that had been rejected by the US Army Air Corps and several export customers) and the Zero, with only a superficial similarity in layout. Allegations about the Zero being a copy have been mostly discredited.
Name
The A6M is universally known as the Zero from its Japanese Navy type designationType (designation)
The word Type followed by a number is a common way to name a weapon or product in a production series, similar in meaning to "Mark". "Type" was used extensively by the Japanese military beginning in the 1920s, and is currently in use by the Chinese military. The United Kingdom uses a type number...
, Type 0 Carrier Fighter (Rei shiki Kanjō sentōki, 零式艦上戦闘機), taken from the last digit of the Imperial year 2600 (1940), when it entered service. In Japan it was unofficially referred to as both Rei-sen and Zero-sen; Japanese pilots most commonly called it, Zero-sen.
In the official designation "A6M" the "A" signified a carrier-based
Aircraft carrier
An aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations...
fighter, "6" meant it was sixth such model built for the Imperial Navy, and "M" indicated the manufacturer, Mitsubishi
Mitsubishi
The Mitsubishi Group , Mitsubishi Group of Companies, or Mitsubishi Companies is a Japanese multinational conglomerate company that consists of a range of autonomous businesses which share the Mitsubishi brand, trademark and legacy...
.
The official Allied code name was "Zeke", in keeping with the practice of giving male names to Japanese fighters, female names to bomber
Bomber
A bomber is a military aircraft designed to attack ground and sea targets, by dropping bombs on them, or – in recent years – by launching cruise missiles at them.-Classifications of bombers:...
s, bird names to glider
Military glider
Military gliders have been used by the military of various countries for carrying troops and heavy equipment to a combat zone, mainly during the Second World War. These engineless aircraft were towed into the air and most of the way to their target by military transport planes, e.g...
s, and tree names to trainer
Trainer (aircraft)
A trainer is a class of aircraft designed specifically to facilitate in-flight training of pilots and aircrews. The use of a dedicated trainer aircraft with additional safety features—such as tandem flight controls, forgiving flight characteristics and a simplified cockpit arrangement—allows...
s. "Zeke" was part of the first batch of "hillbilly" code names assigned by Captain Frank T. McCoy of Tennessee, who wanted quick, distinctive, easy to remember names. When in 1942 the Allied code for Japanese aircraft was introduced, he logically chose "Zeke" for the "Zero." Later, two variants of the fighter received their own code names: the A6M2-N (floatplane
Floatplane
A floatplane is a type of seaplane, with slender pontoons mounted under the fuselage; only the floats of a floatplane normally come into contact with water, with the fuselage remaining above water...
version of the Zero) was called Rufe and the A6M3-32 variant was initially called Hap. After objections from General "Hap" Arnold
Henry H. Arnold
Henry Harley "Hap" Arnold was an American general officer holding the grades of General of the Army and later General of the Air Force. Arnold was an aviation pioneer, Chief of the Air Corps , Commanding General of the U.S...
, commander of the USAAF, the name was changed to Hamp.
Operational history
Polikarpov I-15
The Polikarpov I-15 was a Soviet biplane fighter aircraft of the 1930s. Nicknamed Chaika because of its gulled upper wings, it was operated in large numbers by the Soviet Air Force, and together with the Polikarpov I-16 monoplane, was one of the standard fighters of the Spanish Republicans during...
s and I-16s of the Chinese Nationalist Air Force, shooting down all the fighters without loss to themselves. By the time they were redeployed a year later, the Zeros had shot down 99 Chinese aircraft (266 according to other sources).
At the time of the [attack on Pearl Harbor]] 420 Zeros were active in the Pacific. The carrier-borne Model 21 was the type encountered by the Americans. Its tremendous range of over 2,600 km (1,600 mi) allowed it to range further from its carrier than expected, appearing over distant battlefronts and giving Allied commanders the impression that there were several times as many Zeros as actually existed.
The Zero quickly gained a fearsome reputation. Thanks to a combination of excellent maneuverability and firepower, it easily disposed of the motley collection of Allied aircraft sent against it in the Pacific in 1941. It proved a difficult opponent even for the Supermarine Spitfire
Supermarine Spitfire
The Supermarine Spitfire is a British single-seat fighter aircraft that was used by the Royal Air Force and many other Allied countries throughout the Second World War. The Spitfire continued to be used as a front line fighter and in secondary roles into the 1950s...
. Although not as fast as the British fighter, the Mitsubishi fighter could out-turn the Spitfire with ease, could sustain a climb at a very steep angle, and could stay in the air for three times as long.
Soon, however, Allied pilots developed tactics to cope with the Zero. Due to its extreme agility, engaging in a traditional, turning dogfight with a Zero was likely to be fatal. It was better to roar down from above in a high-speed pass, fire a quick burst, then zoom back up to altitude. (A short burst of fire from heavy machine guns or cannon was often enough to bring down the fragile Zero.) Such "boom-and-zoom" tactics were used successfully in the China Burma India Theater
China Burma India Theater of World War II
China Burma India Theater was the name used by the United States Army for its forces operating in conjunction with British and Chinese Allied air and land forces in China, Burma, and India during World War II...
(CBI) by the "Flying Tigers
Flying Tigers
The 1st American Volunteer Group of the Chinese Air Force in 1941–1942, famously nicknamed the Flying Tigers, was composed of pilots from the United States Army , Navy , and Marine Corps , recruited under presidential sanction and commanded by Claire Lee Chennault. The ground crew and headquarters...
" of the American Volunteer Group (AVG) against similarly maneuverable Japanese Army aircraft such as the Nakajima Ki-27
Nakajima Ki-27
The was the main fighter aircraft used by the Imperial Japanese Army Air Force up until 1940. Its Allied nickname was "Nate", although it was called "Abdul" in the "China Burma India" theater by many post war sources; Allied Intelligence had reserved that name for the nonexistent Mitsubishi Navy...
and Ki-43
Nakajima Ki-43
The Nakajima Ki-43 Hayabusa was a single-engine land-based tactical fighter used by the Imperial Japanese Army Air Force in World War II...
. AVG pilots were trained to exploit the advantages of their P-40s
Curtiss P-40
The Curtiss P-40 Warhawk was an American single-engine, single-seat, all-metal fighter and ground attack aircraft that first flew in 1938. The P-40 design was a modification of the previous Curtiss P-36 Hawk which reduced development time and enabled a rapid entry into production and operational...
, which were very sturdy, heavily armed, generally faster in a dive and level flight at low altitude, with a good rate of roll.
Another important maneuver was Lieutenant Commander John S. "Jimmy" Thach's "Thach Weave
Thach Weave
The Thach Weave or Beam Defense Position is an aerial combat tactic developed by naval aviator John S. Thach of the United States Navy soon after the United States' entry into World War II....
", in which two fighters would fly about 60 m (200 ft) apart. If a Zero latched onto the tail of one of the fighters, the two aircraft would turn toward each other. If the Zero followed his original target through the turn, he would come into a position to be fired on by the target's wingman. This tactic was first used to good effect during the Battle of Midway, and later over the Solomon Islands
Solomon Islands
Solomon Islands is a sovereign state in Oceania, east of Papua New Guinea, consisting of nearly one thousand islands. It covers a land mass of . The capital, Honiara, is located on the island of Guadalcanal...
. Many highly experienced Japanese aviators were lost in combat, resulting in a progressive decline in the quality of the opponents faced by Allied pilots, which became a significant factor in Allied successes. Unexpected heavy losses of these irreplaceable pilots at the battles of the Coral Sea and Midway
Battle of Midway
The Battle of Midway is widely regarded as the most important naval battle of the Pacific Campaign of World War II. Between 4 and 7 June 1942, approximately one month after the Battle of the Coral Sea and six months after Japan's attack on Pearl Harbor, the United States Navy decisively defeated...
dealt the Japanese carrier air force a blow from which it never fully recovered.
In contrast, Allied fighters were designed with ruggedness and pilot protection in mind. The Japanese ace Saburo Sakai described how the resilience of early Grumman aircraft was a factor in preventing the Zero from attaining total domination:
When the powerful Lockheed P-38 Lightning, Grumman F6F Hellcat, and Vought F4U Corsair appeared in the Pacific theater, the A6M, with its low-powered engine, was hard-pressed to remain competitive. In combat with an F6F or F4U, the only positive thing that could be said of the Zero at this stage of the war was that in the hands of a skillful pilot it could maneuver as well as most of its opponents. Nonetheless, in competent hands the Zero could still be deadly.
Due to shortages of high-powered aviation engines and problems with planned successor models, the Zero remained in production until 1945, with over 11,000 of all variants produced. It is said that Zeros destroyed at least 1,550 American aircraft during the course of the war.
Allied opinions
The American military discovered many of the A6M's unique attributes when they recovered a largely intact specimen on Akutan IslandAkutan Island
Akutan Island is an island in the Fox Islands group of the eastern Aleutian Islands in the U.S. state of Alaska. The island is approximately 18 mi in length. It contains the Mount Akutan volcano, which had a major lava eruption in 1979...
in the Aleutians (which was called the Akutan Zero
Akutan Zero
The Akutan Zero, also known as Koga's Zero and the Aleutian Zero, was a type 0 model 21 Mitsubishi A6M Zero Japanese fighter plane that crash-landed on Akutan Island, Alaska Territory, during World War II. It was captured intact by the Americans in July 1942 and became the first flyable Zero...
). During an air raid over Dutch Harbor on 4 June 1942, one A6M fighter was hit by ground fire. Losing oil, Flight Petty Officer Tadayoshi Koga attempted an emergency landing on Akutan Island about 20 miles northeast of Dutch Harbor, but his Zero flipped over in soft ground in a sudden crash landing. Koga died instantly of head injuries, but the relatively undamaged fighter was found over a month later by an American salvage team and shipped to Naval Air Station North Island
Naval Air Station North Island
Naval Air Station North Island or NAS North Island is located at the north end of the Coronado peninsula on San Diego Bay and is the home port of several aircraft carriers of the United States Navy...
where testing flights of the repaired A6M revealed not only its strengths, but also its deficiencies in design and performance.
The experts who evaluated the captured Zero found that the plane weighed 5,200 pounds fully loaded, half the weight of the standard United States Navy fighter. It was "built like a fine watch"; the Zero was constructed with flush rivets, and even the guns were flush with the wings. The instrument panel was a "marvel of simplicity ... with no superfluities to distract [the pilot]." What most impressed the experts was that the Zero's fuselage and wings were constructed in one piece, unlike the American method that built them separately and joined the two parts together. The Japanese method was much slower, but resulted in a very strong structure and improved close manuverability.
Captain Eric Brown, the Chief Naval Test Pilot of the Royal Navy, recalled being impressed by the Zero during tests of captured aircraft. "I don’t think I have ever flown a fighter that could match the rate of turn of the Zero. The Zero had ruled the roost totally and was the finest fighter in the world until mid-1943." American test pilots found that the Zero's controls were "very light" at 200 miles per hour, but stiffened at faster speeds. While stable on the ground despite its light weight, the aircraft was designed purely for the attack role, emphasizing long range, maneuverability, and firepower at the expense of protection of its pilot. Most had neither self-sealing tanks nor armor plating.
Variants
The first A6M1 prototype was completed in March 1939, powered by the 580 kW (780 hp) Mitsubishi Zuisei
Mitsubishi Zuisei
-Bibliography:* Matsuoka Hisamitsu, Nakanishi Masayoshi. The History of Mitsubishi Aero Engines 1915-1945. Miki Press, Japan, 2005. ISBN 4-89522-461-9-External links:...
13 engine with a two-blade propeller. It first flew on 1 April, and passed testing in a remarkably short period of time. By September, it had already been accepted for Navy testing as the A6M1 Type 0 Carrier Fighter, with the only notable change being a switch to a three-bladed propeller to cure a vibration problem.
A6M2 Type 0 Model 11
While the Navy was testing the first two prototypes, they suggested that the third be fitted with the 700 kW (940 hp) Nakajima SakaeNakajima Sakae
|-See also:-Bibliography:*Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9*Jane's Fighting Aircraft of World War II. London. Studio Editions Ltd, 1989...
12 engine instead. Mitsubishi had its own engine of this class in the form of the Kinsei
Mitsubishi Kinsei
|-See also:-Bibliography:* Matsuoka Hisamitsu, Nakanishi Masayoshi. The History of Mitsubishi Aero Engines 1915-1945. Miki Press, Japan, 2005. ISBN 4-89522-461-9...
, so they were somewhat reluctant to use the Sakae. Nevertheless, when the first A6M2 was completed in January 1940, the Sakae's extra power pushed the performance of the Zero well past the original specifications.
The new version was so promising that the Navy had 15 built and shipped to China before they had completed testing. They arrived in Manchuria
Manchuria
Manchuria is a historical name given to a large geographic region in northeast Asia. Depending on the definition of its extent, Manchuria usually falls entirely within the People's Republic of China, or is sometimes divided between China and Russia. The region is commonly referred to as Northeast...
in July 1940, and first saw combat over Chungking in August. There they proved to be completely untouchable by the Polikarpov I-16
Polikarpov I-16
The Polikarpov I-16 was a Soviet fighter aircraft of revolutionary design; it was the world's first cantilever-winged monoplane fighter with retractable landing gear. The I-16 was introduced in the mid-1930s and formed the backbone of the Soviet Air Force at the beginning of World War II...
s and I-153
Polikarpov I-153
The Russian Polikarpov I-153 Chaika was a late 1930s Soviet biplane fighter. Developed as an advanced version of the I-15 with a retractable undercarriage, the I-153 fought in the Soviet-Japanese combats in Mongolia and was one of the Soviet's major fighter types in the early years of the Second...
s that had been such a problem for the A5Ms currently in service. In one encounter, 13 Zeros shot down 27 I-15s and I-16s in under three minutes without loss. After hearing of these reports the Navy immediately ordered the A6M2 into production as the Type 0 Carrier Fighter, Model 11.
Reports of the Zero's performance filtered back to the US slowly. There they were dismissed by most military officials, who felt it was impossible for the Japanese to build such an aircraft.
A6M2 Type 0 Model 21
Aircraft carrier
An aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations...
s. The resulting Model 21 would become one of the most produced versions early in the war. When the lines switched to updated models, 740 Model 21s had been completed by Mitsubishi, and another 800 by Nakajima. Two other versions of the Model 21 were built in small numbers, the Nakajima-built A6M2-N "Rufe" floatplane
Floatplane
A floatplane is a type of seaplane, with slender pontoons mounted under the fuselage; only the floats of a floatplane normally come into contact with water, with the fuselage remaining above water...
(based on the Model 11 with a slightly modified tail), and the A6M2-K two-seat trainer of which a total of 508 were built by Hitachi and the Sasebo Naval Air Arsenal.
A6M3 Type 0 Model 32
Supercharger
A supercharger is an air compressor used for forced induction of an internal combustion engine.The greater mass flow-rate provides more oxygen to support combustion than would be available in a naturally aspirated engine, which allows more fuel to be burned and more work to be done per cycle,...
for better altitude performance, and increased power to 840 kW (1,130 hp). Plans were made to introduce the new engine into the Zero as soon as possible.
The new Sakae was slightly heavier and somewhat longer due to the larger supercharger, which moved the center of gravity
Center of gravity
In physics, a center of gravity of a material body is a point that may be used for a summary description of gravitational interactions. In a uniform gravitational field, the center of mass serves as the center of gravity...
too far forward on the existing airframe. To correct for this the engine mountings were cut down by 20 cm (8 in), moving the engine back towards the cockpit. This had the side effect of reducing the size of the main fuel tank (located to the rear of the engine) from 518 L (137 US gal) to 470 L (120 US gal).
The only other major changes were to the wings, which were simplified by removing the Model 21's folding tips. This changed the appearance enough to prompt the US to designate it with a new code name, Hap. This name was short-lived, as a protest from USAAF commander General Henry "Hap" Arnold
Henry H. Arnold
Henry Harley "Hap" Arnold was an American general officer holding the grades of General of the Army and later General of the Air Force. Arnold was an aviation pioneer, Chief of the Air Corps , Commanding General of the U.S...
forced a change to "Hamp". Soon after, it was realized that it was simply a new model of the "Zeke". The wings also included larger ammunition boxes, allowing for 100 rounds for each of the 20 mm cannon.
The wing changes had much greater effects on performance than expected. The smaller size led to better roll, and their lower drag allowed the diving speed to be increased to 670 km/h (420 mph). On the downside, maneuverability was reduced, and range suffered due to both decreased lift and the smaller fuel tank. Pilots complained about both. The shorter range proved a significant limitation during the Solomons campaign of 1942.
The first Model 32 deliveries began in April 1942, but it remained on the lines only for a short time, with a run of 343 being built.
A6M3 Type 0 Model 22
In order to correct the deficiencies of the Model 32, a new version with the Model 21's folding wings, new in-wing fuel tanks and attachments for a 330 L (90 US gal) drop tank under each wing were introduced. The internal fuel was thereby increased to 570 L (137 US gal) in this model, regaining all of the lost range.As the airframe was reverted from the Model 32 and the engine remained the same, this version received the navy designation Model 22, while Mitsubishi called it the A6M3a. The new model started production in December, and 560 were eventually produced. This company constructed some examples for evaluation, armed with 30 mm Type 5 Cannon, under denomination of A6M3b (model 22b).
A few late-production A6M3 Model 22s had a wing similar to the later shortened, rounded tip wing fitted to the A6M5 Model 52. These were probably a transition model, at least one was photographed at Rabaul-East in Mid-1943.
A6M4 Type 0 Model 41
The A6M4 designation was applied to two A6M2s fitted with an experimental turbo-supercharged Sakae engine designed for high-altitude use. The design, modification and testing of these two prototypes was the responsibility of the at Yokosuka and took place in 1943. Lack of suitable alloys for use in the manufacture of the turbo-supercharger and its related ducting caused numerous ruptures of the ducting resulting in fires and poor performance. Consequently, further development of the A6M4 was cancelled. The program still provided useful data for future aircraft designs and, consequently, the manufacture of the more conventional A6M5, already under development by Mitsubishi Jukogyo K.K., was accelerated.A6M5 Type 0 Model 52
F6F Hellcat
The Grumman F6F Hellcat was a carrier-based fighter aircraft developed to replace the earlier F4F Wildcat in United States Navy service. Although the F6F resembled the Wildcat, it was a completely new design powered by a 2,000 hp Pratt & Whitney R-2800. Some tagged it as the "Wildcat's big...
and F4U Corsair
F4U Corsair
The Vought F4U Corsair was a carrier-capable fighter aircraft that saw service primarily in World War II and the Korean War. Demand for the aircraft soon overwhelmed Vought's manufacturing capability, resulting in production by Goodyear and Brewster: Goodyear-built Corsairs were designated FG and...
, superior mostly for engine power and armament. The variant was a modest update of the A6M3 Model 22, with non-folding wing tips and thicker wing skinning to permit faster diving speeds, plus an improved exhaust system. The latter used four ejector exhaust stacks, providing an increment of thrust, projecting along each side of the forward fuselage. The new exhaust system required modified "notched" cowl flaps and small rectangular plates which were riveted to the fuselage, just aft of the exhausts. Two smaller exhaust stacks exited via small cowling
Cowling
A cowling is the covering of a vehicle's engine, most often found on automobiles and aircraft.A cowling may be used:* for drag reduction* for engine cooling by directing airflow* as an air intake for jet engines* for decorative purposes...
flaps immediately forward of and just below each of the wing leading edges. The improved roll-rate of the clipped-wing A6M3 was now built in.
Sub-variants included:
- "A6M5a Model 52a «Kou»," featuring Type 99-II cannon with belt feed of the Mk 4 instead of drum feed Mk 3 (100 rpg), permitting a bigger ammunition supply (125 rpg)
- "A6M5b Model 52b «Otsu»," with an armor glass windscreen, a fuel tank fire extinguisherFire extinguisherA fire extinguisher or extinguisher, flame entinguisher is an active fire protection device used to extinguish or control small fires, often in emergency situations...
and the 7.7 mm (.303 in) Type 97 gun (750 m/s muzzle velocity and 600 m/1,970 ft range) in the left forward fuselage was replaced by a 13.2 mm/.51 in Type 3 Browning-derived gun (790 m/s muzzle velocity and 900 m/2,950 ft range) with 240 rounds. The larger weapon required an enlarged cowling opening, creating a distinctive asymmetric appearance to the top of the cowling. - "A6M5c Model 52c «Hei»" with thicker armored glass in the cabin's windshield (5.5 cm/2.2 in) and armor plate behind the pilot's seat. The wing skinning was further thickened in localized areas to allow for a further increase in dive speed. This version also had a modified armament fit of three 13.2 mm (.51 in) guns (one in the forward fuselage, and one in each wing with a rate of fire of 800 rpm), twin 20 mm Type 99-II guns and an additional fuel tank with a capacity of 367 L (97 US gal), often replaced by a 250 kg bomb.
The A6M5 had a maximum speed of 540 km/h (340 mph) and reached a height of 8,000 m (26,250 ft) in nine minutes, 57 seconds. Other variants were the night fighter
Night fighter
A night fighter is a fighter aircraft adapted for use at night or in other times of bad visibility...
A6M5d-S (modified for night combat, armed with one 20 mm Type 99 cannon, inclined back to the pilot's cockpit) and A6M5-K "Zero-Reisen"(model l22) tandem trainer
Trainer (aircraft)
A trainer is a class of aircraft designed specifically to facilitate in-flight training of pilots and aircrews. The use of a dedicated trainer aircraft with additional safety features—such as tandem flight controls, forgiving flight characteristics and a simplified cockpit arrangement—allows...
version, also manufactured by Mitsubishi.
A6M6c Type 0 Model 53c
This was similar to the A6M5c, but with self-sealing wing tanks and a Nakajima Sakae 31a engine featuring water-methanol engine boost.A6M8 Type 0 Model 64
Similar to the A6M6 but with the Sakae (now out of production) replaced by the Mitsubishi KinseiMitsubishi Kinsei
|-See also:-Bibliography:* Matsuoka Hisamitsu, Nakanishi Masayoshi. The History of Mitsubishi Aero Engines 1915-1945. Miki Press, Japan, 2005. ISBN 4-89522-461-9...
62 engine with 1,560 hp (1,164 kW), 60% more powerful than the engine of the A6M2. This resulted in an extensively modified cowling and nose for the aircraft. The carburetor intake was much larger, a long duct like that on the Nakajima B6N Tenzan was added, and a large spinner—like that on the Yokosuka D4Y Suisei with the Kinsei 62—was mounted. The larger cowling meant deletion of the fuselage mounted machine gun, but armament was otherwise unchanged from the Model 52 Hei (20 mm cannon x 2; 13 mm/.51 in MG x 2). In addition, the Model 64 was modified to carry two 150 L (40 US gal) drop tanks on either wing in order to permit the mounting of a 250 kg (550 lb) bomb on the underside of the fuselage. Two prototypes were completed in April 1945 but the chaotic situation of Japanese industry and the end of the war obstructed the start of the ambitious program of production for 6,300 machines, none being completed.
Operators
- Indonesian Air ForceIndonesian Air ForceThe Indonesian Air Force is the air force branch of the Indonesian National Armed Forces.The Indonesian Air Force has 34,930 personnel equipped with 110 combat aircraft including Su-27 and Su-30.-Before Indonesian independence :...
- Imperial Japanese NavyImperial Japanese NavyThe Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...
Air ServiceImperial Japanese Navy Air ServiceThe Imperial Japanese Navy Air Service was the air arm of the Imperial Japanese Navy during World War II, the organization was responsible for the operation of naval aircraft and the conduct of aerial warfare in the Pacific War.It was controlled by the Navy Staff of the Imperial Japanese Navy and...
- Republic of China Air ForceRepublic of China Air ForceThe Republic of China Air Force is the aviation branch of the Republic of China Armed Forces. The ROCAF's primary mission is the defense of the airspace over and around Taiwan...
Thailand
- Royal Thai Air ForceRoyal Thai Air ForceThe Royal Thai Air Force or RTAF is the air force of the Kingdom of Thailand. Since its establishment in 1913, as one of the earliest air forces of Asia, the Royal Thai Air Force had engaged in many major and minor battles. During the Vietnam war era, the air force has been developed with USAF-aid...
Survivors
National Air and Space Museum
The National Air and Space Museum of the Smithsonian Institution holds the largest collection of historic aircraft and spacecraft in the world. It was established in 1976. Located in Washington, D.C., United States, it is a center for research into the history and science of aviation and...
, National Museum of the United States Air Force
National Museum of the United States Air Force
The National Museum of the United States Air Force is the official museum of the United States Air Force located at Wright-Patterson Air Force Base northeast of Dayton, Ohio. The NMUSAF is the world's largest and oldest military aviation museum with more than 360 aircraft and missiles on display...
, the National Museum of Naval Aviation
National Museum of Naval Aviation
The National Museum of Naval Aviation is a military and aerospace museum located at Naval Air Station Pensacola, Florida. The museum opened in 1962....
, the Pacific Aviation Museum
Pacific Aviation Museum
The Pacific Aviation Museum Pearl Harbor is located on Ford Island, located in the middle of Pearl Harbor, Hawaii. The museum site occupies of the island...
, the San Diego Air and Space Museum), and the UK (Duxford) as well as the Auckland War Memorial Museum in New Zealand. A restored A6M2-21 (V-173 retrieved as a wreck after the war, and later found to have been flown by Saburō Sakai
Saburo Sakai
Sub-Lieutenant was a Japanese naval aviator and flying ace of the Imperial Japanese Navy during World War II. Sakai was the Imperial Navy's fourth-ranking ace and Japan's second leading fighter pilot to survive the war ....
at Lae
Lae
Lae, the capital of Morobe Province, is the second-largest city in Papua New Guinea. It is located at the start of the Highlands Highway which is the main land transport corridor from the Highlands region to the coast...
) is on display at the Australian War Memorial
Australian War Memorial
The Australian War Memorial is Australia's national memorial to the members of all its armed forces and supporting organisations who have died or participated in the wars of the Commonwealth of Australia...
in Canberra.
Another aircraft recovered by the Australian War Memorial Museum in the early 1970s now belongs to Fantasy of Flight
Fantasy of Flight
Fantasy of Flight is an aviation-related attraction in Polk City, Florida, USA that takes visitors back to the pioneering days of early flight, World War I, World War II and beyond. The attraction opened in November of 1995, and houses the world's largest private aircraft collection on display...
in Polk City, Florida. Along with several other Zeros it was found near Rabaul in the South Pacific. The markings suggest that it was in service after June 1943 and further investigation suggests that it has cockpit features conducive to the Nakashima built model 52b. If this is correct, it is most likely one of the 123 aircraft lost by the Japanese during the assault of Rabaul. The aircraft was shipped in pieces to the attraction and it was eventually made up for display as a crashed aircraft. Much of the aircraft is usable for patterns and some of its parts can be restored to one day make this a basis for a flyable aircraft.
A number of flyable Zero airframes exist; most have had their engines replaced with similar American units; only one, the Planes of Fame Museum's A6M5 example, bearing tail number "61-120" has the original Sakae engine, as seen in a flight demonstration video of this aircraft.
Although not truly a survivor, the "Blayd" Zero is a reconstruction based on templating original Zero components recovered from the South Pacific. In order to be considered a "restoration," the builders used a small fraction of parts from original Zero landing gear in the reconstruction. The aircraft is now on display at the Fargo Air Museum
Fargo Air Museum
The Fargo Air Museum is an aviation related museum in Fargo, North Dakota. It is located near Hector International Airport in the northern part of the city. The museum includes many historic aircraft of which 90% are in flying condition. There is also a full-scale replica of a Wright brothers...
in Fargo, North Dakota.
The rarity of flyable Zeros accounts for the use of single-seat North American T-6 Texan
North American T-6 Texan
The North American Aviation T-6 Texan was a single-engine advanced trainer aircraft used to train pilots of the United States Army Air Forces, United States Navy, Royal Air Force and other air forces of the British Commonwealth during World War II and into the 1950s...
s, modified externally and painted in Japanese markings, to stand in for the fighter in the films Tora! Tora! Tora!
Tora! Tora! Tora!
is a 1970 American-Japanese war film that dramatizes the Japanese attack on Pearl Harbor, to the extent these facts were known at the time of production. The film was directed by Richard Fleischer and stars an all-star cast, including So Yamamura, E.G...
, The Final Countdown, and many other television and film depictions of the aircraft, such as Baa Baa Black Sheep
Baa Baa Black Sheep (TV series)
Baa Baa Black Sheep is a television series that aired on NBC from 1976 until 1978. Its premise was based on the experiences of United States Marine Corps aviator Pappy Boyington and his World War II "Black Sheep Squadron". The series was created and produced by Stephen J. Cannell...
(renamed Black Sheep Squadron). One Model 52 was used during the production of Pearl Harbor
Pearl Harbor (film)
Pearl Harbor is a 2001 American action drama war film directed by Michael Bay and produced by Jerry Bruckheimer and Randall Wallace, who wrote the screenplay...
.
Specifications (A6M2 Type 0 Model 21)
See also
External links
- Tour A6M5 Zero cockpit
- Mitsubishi A6M Zero Japanese fighter aircraft—design, construction, history
- WW2DB: A6M Zero
- www.j-aircraft.com: Quotes A6M
- THE MITSUBISHI A6M ZERO at Greg Goebel's AIR VECTORS
- Imperial Japanese Navy's Mitsubishi A6M Reisen
- Planes of Fame Museum's Flightworthy A6M5 Zero No. "61-120"
- War Prize: The Capture of the First Japanese Zero Fighter in 1941
Video links