their area of operations in the Indian Ocean.
In July, Kōkūtai 331 was established with this
task. The main base was Sabang, north of Sumatra and the unit also used airfields in the Andaman and Nicobar Islands, where it primarily faced
the RAF. However, it also operated in Thailand and
Burma. For a short time, it was a mixed unit that
also used single-engine bombers.
In October 1943, Kōkūtai 381 was formed. Its main
task throughout the following year was the defense of the oil refineries in Borneo. With A6M2 Type
21 fighters, Kōkūtai 381 conducted about half of
its fighter sorties at night. Phosphorus air-to-air
bombs were often used during the interception
missions. The Kōkūtai 381 was gradually expanded to include other parts that used twin-engine
night fighters and single- and twin-engine bombers. Nevertheless, it retained its designation as
an interceptor unit.
Marshall, Caroline, and Mariana Islands
Japanese aircraft carrier Shōhō under attack by U.S. Navy carrier aircraft in the late morning of May 7, 1942. It was the first Japanese aircraft
carrier lost in combat.
(Photo: Official U.S. Navy Photograph, National Archives)
tion “I-gō” was planned, in which raids were conducted between April 7 and 14 against Guadalcanal, Oro Bay, Port Moresby and Milne Bay. More
than 200 A6M2 and A6M3 aircraft were available
for fighter escort from Kōkūtai 204, 253, and 582
and from the fighter units of the carriers Zuikaku,
Zuihō, Junyō and Hiyō. The result of the action was
judged as a great success. However, both sides
actually suffered negligible losses. After the operation ended, on April 18, a bomber with Admiral
Isoroku Yamamoto on board was shot down over
Bougainville Island during an inspection tour. Based on decoded radio intercepts, American P-38
fighters were in the right place at the right time.
The commander of the Combined Fleet and one of
the architects of the attack on Pearl Harbor died
exactly one year after Doolittle‘s raid on Tokyo.
In May 1943, Kōkūtai 251 returned to Rabaul, just
in time to join the attacks on Allied forces fighting
their way from Guadalcanal farther northwest.
The Japanese made a tremendous effort to stop
the offensive, but their efforts were futile. The Japanese made their last raid on Guadalcanal on
June 16, 1943. Of the 24 dive bombers, 13 crews
were lost and the fighter escort of 70 Zeros had to
write off 15 aircraft. The Allies suffered minimal
Retreat and defense of Rabaul
In late June 1943, the Allies landed on New Georgia and captured Munda airfield. This was followed by the defensive battles of Vella Lavella in
August and Buin during September and October.
In this period Zero pilots met F6F Hellcat fighter
in combat for the first time. Kōkūtai 201 returned
to the battlefield from Japan and naval fighters
in the area were reinforced by the carrier-based
fighter units of HIJMS Junyō and Ryūhō. The Zero
pilots managed to keep their win-loss ratio at
a reasonable level in combat with enemy fighters. However, bomber crews were constantly
suffering high losses. It was a problem for which
the high command had no solution. The „Kate“ and
„Val“ bombers were already obsolete, and their
design provided little protection against heavily
armed Allied fighters.
At the end of October 1943, the last fighter units
withdrew from Bougainville to Rabaul. They began to face a systematic bombing campaign by
aviation units of Marine Corps, Air Force and Navy
as well as other Allied air forces. The core of the
defense of this strategic base was Kōkūtai 201,
204 and 253. At the time, they used A6M fighters
Type 22, 52 as well as good old 21. They were
briefly supported or resupplied by carrier units.
In November, for a short time, fighters arrived
from Zuihō, Shōkaku and Zuikaku. In late December 1943 they were followed briefly by Zero pilots
from Hiyō and Ryūhō. From the Japanese point of
view, during this period Rabaul could be likened
to a meat grinder. In early January Kōkūtai 201
had to be withdrawn. After less than a month exhausted Kōkūtai 204 moved from Rabaul too. Losses were replaced by fighters from the carriers
Jun´yō, Hiyō and Ryūhō, who together with Kōkūtai 253 held out for a month in defensive aerial
battles. In late February 1944, fighter units began
to withdraw from Rabaul to Truk. Although the
high command promised to turn the units back,
this never happened, and the Allies neutralized
the base until the end of the war. With the end of
the fighting over Rabaul, the Japanese naval air
force lost most of its seasoned fighter veterans.
China, India, and Indonesia
As Allied air raids against targets on the Chinese
mainland and Taiwan intensified, the Japanese
Navy decided to establish Kōkūtai 254. In October 1943, it began operations in Hong Kong, and
detachments later operated from other bases.
In February 1944, Kōkūtai 256 was formed in
Central China. Their opponents were primarily
American bombers. By the end of 1944, both units
were deployed in the defense of Taiwan and the
Philippines. Due to heavy casualties, their remaining parts were absorbed into another unit in
The Japanese Army Air Force had to focus on
fighting for northern New Guinea in 1943. Therefore, the Japanese Naval Air Force took over
In early 1943, Kōkūtai 201, which had withdrawn
from Rabaul, was stationed with its Zeros in the
Marshall Islands. After transfer to Japan, this area
was taken over in February 1943 by Kōkūtai 252.
It had bases primarily on the islands of Kwajalein,
Maloelap, Nauru, Roi, and Wake. The Unit mostly
encountered American four-engine bombers, but
in the fall of 1943, it went through heavy combats
with US Navy “Hellcats”. Therefore Kōkūtai 281
arrived in November as a reinforcement. During
the capture of the Marshall Islands in February
1944, Kōkūtai 281 was completely destroyed, and
its last pilots were killed in ground combat. Part
of Kōkūtai 252 was evacuated to Japan. At the beginning of 1944 Zero Type 21 began to be used also
as fighter-bomber. One of the first units to take
over the Zero for this purpose was the bomber
Kōkūtai 501. From January 1944, fighter-bomber
pilots were trained at Truk. Kōkūtai 201 and 204
also withdrew to this area from Rabaul. However,
after fighting with US Navy aircraft, the remnants
of these units flew to the Philippines in March or
were absorbed by other units. They were replaced
by several newly organized Kōkūtais. Some were
already to be armed with the new “George” and
“Jack” fighters, but all ended up using A6M Zeros,
primarily Type 52, partly also Type 21. Prior to the
Battle of the Marianas, Kōkūtai 261 was stationed
in the area of Saipan and Meleyon, Kōkūtai 263 on
Guam, Kōkūtai 343 on Tinian, Kōkūtai 202 on Moen
and Truk, and Kōkūtai 253 on Eten.
A major reorganization took place in the carrier
units. Within new organization they were divided
into three Kōkūtai units. The bombers, fighters,
fighter-bombers, and reconnaissance aircraft on
the HIJMS Taihō, Shōkaku, and Zuikaku fell under
Kōkūtai 601. Kōkūtai 652 operated from the decks
of HIJMS Jun‘yō, Hiyō, and Ryūjō, and Kōkūtai 653
airmen were assigned to the carriers Chiyoda,
Chitose, and Zuihō. Among the new specialties
of the carrier units were the fighter-bombers.
Their mission was to attack vessels that were
protecting enemy carriers. The purpose was to
damage or sink them and draw part of the AA
fire from bombers. For this purpose, seven of the
above vessels had on board squadrons of A6M2
Model 21 fighter-bombers.
The Battle of the Philippine Sea, which occurred
on June 19 and 20, 1944, was the largest carrier
engagement in history. A Japanese task force of
nine carriers faced fifteen American “flat tops”.