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| Nakajima Ki-43 "Hayabusa" (Oscar) was found "on an airstrip in the Korako area, three miles south of Aitape, New Guinea" on April 22, 1944. The location is probably Tadji airfield. |
by Hiroyuki Shindo
From February 1942 until July
1944, a war of attrition was fought by the air forces of the United States,
Australia and Japan in Papua, New Guinea, the Bismarck Archipelago and the
Solomon Islands. Although this period comprises more than half the length of
the war in the Pacific, somehow more attention seems to be paid in popular
histories to other aspects of that war, such as the actions of the carrier
fleets of Japan and the United States. The air campaign in the South Pacific,
however, was of extreme importance, not just to the persons of all sides who
fought there, but to the outcome of the war. This is because it was in, over
and around the island of New Guinea that the Japanese Army and Navy, and their
air forces, were first stopped, worn down and finally pushed back. Since it is
obviously impossible to look at every aspect of that campaign in a single
article, the following discussion concentrates on the major strategic and
operational issues on the Japanese side. It also focuses on Japanese air
operations over the main island of New Guinea, even though in actuality these
operations, when seen from the Japanese side, were closely intertwined with
activities undertaken in the Solomon Islands.
Broadly speaking, the Japanese
air campaign over New Guinea may be divided into four phases. The first phase
was the Japanese Navy's offensive campaign against Port Moresby, from the
spring through fall of 1942. Next, from early 1943 until about June of that
year, the Japanese Army filled in for the Navy (whose air forces were
increasingly committed to the Solomons campaign) and fought a campaign which
was intended to be offensive but became increasingly defensive in nature. The
third phase was a short period in the summer of 1943 in which the Japanese Army
assigned a more positive role to its air forces in New Guinea, only to see the
bulk of that force destroyed in a single air attack. Finally, the Japanese Army
air forces fought an unglamorous defensive campaign for approximately a year,
from the summer of 1943, before the Japanese Army was pushed out of New Guinea
and the war itself shifted to the Marianas and the Philippines.
Occupation of Rabaul and the Start of Air Operations Against
Port Moresby
When the Japanese Army and Navy
developed plans for a forthcoming war with the United States and Great Britain
in 1941, the islands of the Bismarck Archipelago, particularly New Britain,
were included in their target list from early on. This was because Japanese
planners (especially those in the Navy) saw Rabaul on New Britain, with its
excellent natural harbor, as a potential threat to Truk Island in the
Carolines. Situated only 1100 kilometers from Rabaul, Truk was the site of the
Japanese Navy's most important base in the central Pacific Ocean. The seizure
of New Britain was therefore necessary to protect the base at Truk, and the
surrounding islands had to be controlled as well, in order to secure Rabaul.
While the main efforts of the Army and Navy would be aimed at the southwest
Pacific area - i.e. the Philippines, Malaya, Singapore, Netherlands East Indies
and other surrounding areas that made up the so-called "Southern Resources
Area" - both the Army and Navy therefore assigned units to operations in
the South Pacific.
In the plans which received
imperial sanction on 5 November 1941, the Army's South Seas Detachment was
assigned the task of seizing first Guam, then airfields in the Bismarck
Islands, in order to eliminate the threat posed by the enemy. Since the
operation in the South Pacific was seen as the Navy's responsibility, however,
the Navy's Special Landing Forces were to take over the occupation of Guam at
an appropriate time, after which they would cooperate with the Army in
occupying Rabaul. It was further specified that the South Seas Detachment would
be replaced by the Special Landing Forces and withdrawn to the Palau Islands as
soon as possible. The Navy's Fourth Fleet, based in Truk, would be responsible
for supporting both the Guam and the Rabaul-Bismarcks operations. A sea-borne
assault on Rabaul was accordingly made on 22 January 1942 by the Special
Landing Forces, with the support of both land-based and carrier-based aircraft,
and the town quickly captured.
While these operations were being
carried out, the Japanese Army and Navy, faced with the unexpectedly rapid
success of their operations in the Philippines, Malaya and Netherlands East
Indies, had to decide upon their next steps. Briefly speaking, Japan's options
included continuing westward into India; invading the Australian mainland;
invading New Guinea, the Solomons, Fiji and Samoa, in order to cut off
Australia from the United States; and driving eastward towards Hawaii. The Navy
High Command wanted to invade Australia, in order to eliminate it as potential
springboard for a counter-offensive by the Allies, but the Army balked at this
because it would require an excessive commitment of manpower. The Navy
therefore settled for the lesser option. The Fourth Fleet, with the XI Air
Fleet (the Navy's land-based air force in the Pacific theatre), was ordered to
assault Lae, Salamaua in New Guinea, Port Moresby in Papua, and the Solomon
Islands.
In compliance with this strategy,
Zero fighters of the Chitose Air Corps moved to Rabaul on 31 January. Shortly
afterwards, on 2 and 5 February, Kawanishi Type 97 "Mavis" flying
boats of the Yokohama Air Corps bombed Port Moresby for the first time, and the
air war over New Guinea was underway. On 9 February, Gasmata (on New Britain's
southern coast) was occupied, and work begun on an airstrip. To carry out
further operations, the 4th Air Corps was newly created, with a nominal
strength of 27 fighters and 27 bombers. It was placed under the command of the
25th Air Flotilla, and its headquarters was located in Rabaul. On 24 February,
aircraft from the 4th Air Corps began bombing Port Moresby.
On 7 March 1942, the Japanese
High Command decided upon the operations which would follow the so-called
"First Stage Operations," which had been aimed at the occupation of
the Netherlands East Indies and other areas of the Southern Resources Area. The
second stage of operations which was thus adopted called for the continuation
of major offensive operations in order to secure a long-term, unbeatable
politico-strategic situation, after which additional active measures would be
taken aimed at forcing Great Britain to capitulate and making the United States
lose the will to fight.1 As part of this new strategy, the decision
was made to continue the advance in the Solomons and New Guinea area, with the
aim of eventually cutting off the supply route between the United States and
Australia. The 7 March decision therefore confirmed what was already being
executed. Lae and Salamaua on the northeastern New Guinea coast were occupied
on 8 March. Two days later, the Tainan Air Corps (one of the fighter units
deployed to Rabaul as part of the new strategy) sent eleven of its Zero
fighters to Lae, which became an exceedingly busy advanced airbase.2
Until the end of July 1942, the
naval air units based at Rabaul and Lae became intensely involved in flying
missions over the Owen Stanley Range to attack Port Moresby, or other Allied
bases on the New Guinea mainland. Such operations consisted of either bombing
missions with fighter escort, or sweeps by fighters alone. The Japanese fighter
units at this time were also kept extremely busy intercepting Allied air
attacks on the Japanese bases. This phase of the air war was characterized by
the lack of clear superiority by either side. Although the Australians and
Americans often lost more aircraft in individual air battles, Allied air
strength did not diminish significantly. On the other hand, the Japanese,
although suffering fewer losses, saw a slow decline in the quality of their
forces as highly-trained and experienced pilots were lost and replaced by less
and less experienced ones. This period was, therefore, somewhat of a stalemate,
as the Japanese could not batter the Allied air forces enough to drive them out
of New Guinea.
The Commitment of Army Air Forces to the South Pacific
The next stage in Japanese air
operations over New Guinea involved the deployment of Japanese Army air forces
in the region. After the Americans landed on Guadalcanal Island in the Solomons
on 7 August 1942, the Japanese air forces based in Rabaul became involved in a
two-front operation. Now they were forced to make increasingly greater efforts
in the Solomons, while continuing their campaign against New Guinea (which
still principally meant Port Moresby). The air battle in the Solomons would be
fought principally by naval aircraft, and, as this commitment grew, the Army's
air forces would play a greater role over New Guinea.
The American counter-attack at
Guadalcanal came as a complete surprise to the Japanese. In their estimate of
the world strategic situation in March 1942, the Japanese High Command had
concluded that the Americans would not mount a major counter-attack before
1943. On 12 August the Army and Navy High Commands agreed that the American
landing on Guadalcanal was only a local tactical move, and the island could be
easily recaptured. This view began to change after the Battle of the Tenaru
River on 21 August, when the Japanese Army's Ichiki Detachment, numbering some
900 men, made the first attempt to retake Henderson Field and was almost
completely wiped out. The Japanese Navy High Command now realized that it would
take more than a simple operation to retake Guadalcanal, and that controlling
the air around the island was a prerequisite for success. The Navy felt,
however, that it alone was unable to make the necessary commitment in terms of
air forces, due to the depletion of its air units in Rabaul. In late August it
therefore asked the Army to send some of its forces to reinforce the air effort
in the Solomons and New Guinea area.3
The Army considered the Navy's
request, and almost immediately rejected it. First of all, the Army was not
inclined to make a major commitment in the South Pacific area, because it still
felt that its traditional area of responsibility was the Asian mainland, while
the Pacific Ocean area was the traditional responsibility of the Navy. This had
been the understanding since the establishment of the Japanese Army and Navy in
the late 19th Century, and while there was no formal written agreement to this
effect, the Army and Navy's doctrines, training, tactics, strategy and
equipment were all based upon it. Over the years the Army's air units had been
prepared almost solely for fighting a war with Japan's traditional enemy on the
continent, Russia. The Army had never even considered the possibility of
conducting air operations in the New Guinea-Solomons area, and recognized that
it knew almost nothing about the geographic, climatic and other conditions of
the South Pacific. Not only was the Army extremely reluctant to commit its air
forces in such circumstances, but it suspected that the Navy actually did have
additional air forces in quieter areas of the Pacific which it could commit to
the South Pacific.
The Army formally replied to the
Navy in late August. Besides the reasons given above, the Army explained that
its air forces were spread out all over Manchuria, China, Burma and Sumatra,
and in addition had to defend the Japanese homeland from possible threats from
the North Pacific area. There were, it claimed, no personnel or aircraft that
could be spared for the South Pacific. The Army also pointed out that its air
forces had been trained and prepared for mainland operations, and were
ill-suited for conducting operations or deployments over large expanses of
water, which would be the case if they were committed to this new theatre.
Furthermore, it was mentioned that there were no overland air routes to the
South Pacific front which Army air units might follow, and that airfields and
other necessary facilities were too unprepared there for them to operate
properly. Thus, no agreement was reached at this stage concerning the
deployment of Army air forces to the South Pacific.
In mid-September a further
attempt to retake Henderson Field which the Army mounted, using the Kawaguchi
Detachment, also failed. As preparations commenced for yet another attempt
involving the 2nd Division, the need for regaining command of the air around
the Solomons was keenly recognized by Army planners. Gradually, opinion within
the Army High Command began tilting towards the deployment of Army air forces
to the region. In late October a proposal was produced by the Operations Section
of the Army General Staff for the assignment of two fighter and two light
bomber sentais (air groups) to support Army operations in New Guinea. This,
however, was only intended as a temporary measure to help out the Navy while
its air units were committed to the Guadalcanal campaign. (In fact, by then the
Navy's major bombing missions against Port Moresby from Rabaul had all but
ceased, except for night raids by one or a few planes at a time, as more and
more Navy planes were sucked into the Guadalcanal campaign.) As soon as Port
Moresby was captured, it was intended that the Army air forces would be pulled
out again.
The issue was settled shortly
afterwards. From 28 October, Takushiro Hattori of the Operations Section, Army
General Staff, visited the New Guinea-Solomons front, including XVII Army headquarters
on Guadalcanal. His report dated 11 November called for, among other things,
the deployment of army air forces to the region in order to regain air
superiority. In mid-November, the Army and Navy High Commands and the
Government produced an estimate of future American air power which projected
that the Americans would have in the South Pacific some 11,000 army and navy
first-line planes by December 1942, and 24,500 by December 1943. It was
recognized that the most urgent need facing Japan was to increase her air
power.
Faced with looming defeat on
Guadalcanal, and with setbacks in their drive on Port Moresby where Japanese
forces had begun withdrawing from Kokoda on 26 October, the Army finally
decided to commit some of its air forces to the South Pacific. On 18 November
an "Army-Navy Central Agreement on Operations in the South Pacific
Area" was signed, and the 6th Air Division was committed to the New Guinea
front. This, it should be noted, was only a temporary arrangement to support
the Navy's operations - that is, the Army units would be "loaned"
until the Navy's air forces recovered or certain victorious conditions (such as
the occupation of Port Moresby) were attained. In accordance with the agreement,
sixty Nakajima Type 1 "Oscar" fighters of the 11th Sentai reached
Rabaul via Truk on 18 December, and almost immediately became involved in air defense
operations. By the end of the month they were flying missions against targets
on mainland New Guinea, such as Buna, some of these as joint missions with Navy
aircraft. On 29 December, heavy bomber units of the Army were ordered to deploy
from Burma to New Guinea.
Six weeks later, on 3 January
1943, another Army-Navy Central Agreement was signed which designated the areas
of responsibility of the Army and Navy's air units. The Army air forces were
given the mission of supporting the ground forces on New Guinea and providing
their air defense, and supporting the transport of supplies to New Guinea. The
Navy air forces would be responsible for air operations in the Solomons, and
for air operations in New Guinea other than those assigned to the Army.4
While the decision to withdraw
from Guadalcanal was made at the end of 1942, on 4 January the Army and Navy
High Commands ordered that operations on New Guinea were to be continued. The
purpose of Japan's operations in the South Pacific was to be to "secure a
position of superiority". Lae, Salamaua, Wewak and Madang on New Guinea
were to be strengthened or occupied, and the area north of the Owen Stanleys was
to be secured so that it could function as a base for operations aimed at Port
Moresby.5 The Japanese then had 164 Army and 190 Navy aircraft on
their bases at Rabaul and the surrounding area. At this stage, therefore, the
Japanese had decided to abandon the southern Solomons but still intended to
continue offensive operations in New Guinea, aimed at the eventual capture of
Port Moresby.
Thereafter, Japanese air
operations over New Guinea were conducted principally by the Army, operating
out of Wewak and other bases. In addition to bombing raids on Allied airbases,
the Japanese air forces also had to take on ground support missions (although
never conducted as closely as was the case with the Allied air and ground
forces), combat air patrol over their own airbases and escort missions of ship
transports operating around New Guinea. As was the case with the Japanese Navy
aircraft operating against Port Moresby in mid-1942, however, the Japanese
never really gained the initiative in the air, and instead were gradually
pressed into the defensive.
The Japanese were acutely aware
of the gradually growing strength of the Americans during this period. At the
end of January 1943, the Japanese Army estimated that American strength in the
New Guinea area was 300 aircraft - the same as the combined strength of the
Japanese Army and Navy. They estimated, however, that the Americans were
producing 4,000 aircraft per month, of which the South Pacific would receive
480 (and the New Guinea front at least 80) aircraft per month. Judging that the
Americans would suffer losses of 50 per cent per month, the Japanese Army
projected that the Americans would have 700 aircraft in the New Guinea area by
June, and 950 by September. Compared to this, the combined strength of the
Japanese Army and Navy in the New Guinea-Solomons area was projected to grow to
possibly 350 in June, but was not expected to exceed that number at any time.6
The Japanese were therefore clearly aware that if the current situation
continued, the Americans would gradually attain a sheer superiority in numbers
through 1943.
After the Japanese successfully
withdrew from Guadalcanal in early February 1943, the next major setback which
befell them was the Battle of the Bismarck Sea on 2-3 March that year. In this
action, an entire convoy of transports carrying the 51st Division and a large
amount of heavy weapons and supplies earmarked for the reinforcement of Lae,
was sunk in the Dampier Straits, along with four out of eight escorting
destroyers. As a result of this disastrous defeat, which occurred even though
the Japanese had provided the convoy with what they believed was an adequate
fighter escort, the Japanese were forced to realize that they could no longer
run major convoys of transports in areas where the Americans were able to
operate their bombers more or less freely. This posed obvious problems for the
supply of the Japanese troops on New Guinea.
Following the Bismarck Sea
battle, the Army reconsidered its entire New Guinea strategy, including the
possibility of abandoning New Guinea outright and withdrawing to a new
defensive line. This option was not adopted, however, because the Navy's
operations - not only in the New Guinea area but also throughout the South
Pacific - would be constricted by such a pullback by the Army. In addition, no
new defensive line to which the Army might safely fall back was prepared, and
in any case, such a retreat would only expose the Philippines, Celebes and
other Japanese-held islands in the South Pacific to air attack. Joint Army-Navy
studies which were held on 14 March confirmed this policy, and the Army continued
to try to hold its current positions in New Guinea.7
Further Commitment and Destruction of Army Air Forces
The lopsided defeat in the
Bismarck Sea was an enormous shock to the Army High Command, which was forced
to recognize even more the importance of the New Guinea front to Japan's war
efforts, and that the situation there was extremely critical. As a result, the
Army had to rethink its strategy for the Pacific War, and decided to make a
further substantial commitment to the area, in both ground and air forces. On
25 March 1943, a revised Army-Navy Central Agreement was concluded between the
Army and Navy High Commands.8 Regarding the South Pacific, it was
agreed that the main weight of operations would be placed on the New Guinea
front, i.e. the defense of Lae and Salamaua and the strengthening of bases
along the northern coast, while a holding or delaying operation would be fought
in the Solomons. The assault on Port Moresby, while officially still a
long-term objective, was for all practical purposes abandoned, although lip
service was still paid to it to avoid damaging the morale of the troops
fighting in New Guinea.
Reflecting this revised strategy,
the Army decided to strengthen its air forces in the New Guinea area. Earlier,
on 18 March, the Army High Command had decided to strengthen its air forces in
the South Pacific generally, starting with the replacement of the fighter units
in the 6th Air Division. The newly assigned units were the 68th and 78th
Sentais of the 14th Air Brigade, which flew the Kawasaki Type 3
"Tony" fighter. These units started arriving in Rabaul in late April,
and were duly deployed to New Guinea. On 2 April the Army further decided to
dispatch to the New Guinea front, among other units, the 13th Sentai (flying
the Kawasaki Type 2 "Toryu" twin-engine fighter) and the 24th Sentai
(flying the venerable "Oscar"). These units began arriving in Rabaul
in the latter half of May.
The situation changed further
when the Japanese discovered that the Allies were constructing airfields in the
New Guinea highlands, at Mount Hagen and Bena Bena, which would threaten the
Japanese airfields at Madang and Wewak. Ground operations to meet these new
threats were immediately planned. As a further measure it was decided to send
to New Guinea the 7th Air Division, which was a relatively new formation,
having been formed in late January 1943. It had been previously assigned to
bases in eastern Java, Timor and other islands in the East Indies, and, along
with the defense of this area, had been scheduled to carry out air raids on the
Port Darwin area. In order to meet the extremely pressing situation in New
Guinea, however, it was ordered to deploy to Wewak on 19 June.
Thus, the Japanese Army was
busily deploying new air units to the New Guinea front in the spring and summer
of 1943. While the actual movement of these forces was delayed due to the
insufficient readiness of bases in the New Guinea, among other reasons, Army
air strength - at least on paper - was steadily reinforced during this period.
The Army made another organizational change during this period, when it created
the Fourth Air Army to exercise overall command over the 6th and 7th Air
Divisions. The new air army was formed in mid-June, and its headquarters began
deploying to Rabaul from 25 July through 10 August.
These moves were important
because they indicated a shift in the Army's stance concerning its air forces
in the New Guinea area. Until then, the Army had considered its air forces in
the South Pacific as a temporary measure, a backstop for the Navy's efforts in
the region. Over the spring and summer of 1943, however, the Army came to
recognize fully that the defense of northern New Guinea against the Allied
advance was its responsibility, and began to deploy additional air forces from
Manchuria and elsewhere to the New Guinea front. Eventually about a quarter of
the Army's air forces would be committed to the South Pacific. Considering that
most of these units were the best that the Army had, and would be subjected to
losses of approximately 50 per cent per month, this was indeed a major
commitment by the Army.9
As mentioned above, the 7th Air
Division was ordered to deploy to New Guinea on 19 June 1943. The major 7th Air
Division units which were transferred at this time were the 59th Sentai
(fighters), 5th Sentai, 7th Sentai (heavy bombers) and 61st Sentai (heavy
bombers). While the Eighth Area Army, which commanded the Army ground and air
forces in the Solomons-New Guinea region, wanted the move to occur as soon as
possible, the 7th Air Division resisted, citing the lack of readiness of the airfields
to which they would deploy. Ultimately, it was not until mid-July that the
fighter units were transferred, with the bomber and other units following in
late July and beyond.10 Meanwhile, on 9 July, the 6th Air Division
also moved its headquarters to Wewak.
With these new deployments, it
seemed that the Army air forces had overcome the growing disparity between the
Japanese and the Allied air forces. However, in mid-June, the Army finally had
to face reality, and the Operations Section of its High Command agreed upon an
"Outline for Operations Guidance in the New Guinea Area" with the
Operations Sections of the Navy High Command, which called for a holding
strategy in New Guinea.11 While this meant that the assault on Port
Moresby was finally and formally shelved, the Army air forces in New Guinea
still had the task of neutralizing the Allied air bases at Mount Hagen, Bena
Bena, Wau, Salamaua and other places. In addition, they had to defend their own
airbases, and provide fighter escort for convoys attempting to supply the
Japanese garrisons on New Guinea.
Defensive tasks sapped much of
the Japanese Army's air strength on New Guinea. In fact, by this time the Army
air forces were fighting a largely defensive campaign. Out of 1,308 sorties
flown in July 1943, 494 were convoy escort, 84 were intercept and 190 were
ground support. Such missions meant that fewer aircraft and pilots were
available for mounting air attacks on Allied airbases, even though the need for
such air attacks was well-recognized as necessary for regaining air
superiority.12
In early August 1943, the Fourth
Air Army had an operational strength of 130 aircraft (the Navy's operational
strength in the Solomons-New Guinea area at this time was approximately 220
aircraft).13 This was just one-third of what the Fourth Air Army was
supposed to have on paper, and was also only an operational rate of
approximately 50 per cent. The major causes of this low operational rate were
widespread illness among the aircrews, along with, of course, the lack of
aircraft replacements.
Nevertheless, the Japanese
attempted to carry out their plan to regain air superiority. On 12 August, the
Fourth Air Army began to carry out air raids on the Allied airbases at Hagen,
Bena Bena, Wau, Salamaua and elsewhere. This effort came to naught, however,
when on 17 August 1943 Allied air armadas mounted a surprise air attack on Wewak,
which was the Japanese Army's principal airbase on New Guinea. As a result of
this action, over 100 Japanese aircraft were destroyed, and the Fourth Air Army
was reduced to an operational strength of just over 30 planes. The destruction
of the Japanese air forces meant that the Allies could now conduct air
operations more or less freely as far northwest as Aitape, whereas until then
they had been held to Madang.14
The Army took this defeat quite
seriously, since it meant a virtual end to air operations in New Guinea for the
time being. The major cause for the scale of the defeat, as stressed by Eighth
Area Army, was said to be the unpreparedness of the Japanese airbases. In
particular, it was pointed out that the lack of sufficient aircraft shelters had
left the Japanese planes vulnerable. In addition, the lack of a sufficient
warning system was also identified as a culprit. The Japanese were still
relying almost completely on a visual warning system, which did not provide
enough time for aircraft on the ground to either scramble or be hidden. This
problem was made worse by, again, the primitive condition of the airfields,
which did not allow the quick scrambling of a large number of aircraft.
Yet another major cause stressed
by the Fourth Air Army was the fact that all of its planes had been based on
Wewak and other airbases which were, quite literally, in the front line. The
Fourth Air Army, along with the 6th and 7th Air Divisions, had wanted to deploy
its units more in depth, with a certain number of aircraft based at airfields
further to the rear. However, both the Army High Command and the Eighth Area
Army had insisted that as many aircraft as possible be based at airfields at
the front, to make them easier to use in operations. While this was to a certain
extent inevitable, since the Japanese did not have the necessary number of
airbases in the rear, it also meant that the bulk of their aircraft would be
based in locations extremely vulnerable to large-scale enemy air attacks.
The End of the Japanese Air Forces in New Guinea
After the debacle at Wewak, the
Army tried to replenish its losses. At the same time, it began to strengthen
its airbase at Hollandia, in order to provide more depth to the Wewak position.
The Allies, however, would not wait while these efforts were being made. In
September, the Allies pushed the Japanese back from their positions at Lae and
Salamaua, and on 22 September they landed near Finschhafen, on the northeastern
coast of New Guinea. Despite their desperate defensive efforts, therefore, the
Japanese continued to slowly be pushed back in New Guinea, and in the Solomons
as well. In late September, the Army air forces had at their disposal only 60
or 70 operational aircraft with which to oppose the Americans in New Guinea,
even though they had two air divisions, the 6th and 7th, in the area.15
Faced with these developments,
the Japanese High Command was finally forced to make a major strategic change.
On 15 September 1943 the concept of the Absolute National Defence Zone was adopted
as policy, finally revising the strategy of 7 March 1942, mentioned above,
which had called for the continuation of major offensive operations in order to
secure a undefeatable strategic situation. Under the Absolute National Defence
Zone concept, a delaying action would be continued in the South Pacific while a
new line of defense was prepared along the Marianas-Carolines-Philippines arc.
Here it was hoped that the Americans would be smashed when they tried to
assault it. Counter-offensives would follow, and, if the situation permitted,
offensive operations in New Guinea would be resumed in mid-1944 or later.16
The Army and Navy High Commands
adopted new strategies based upon the new concept on 30 September. Regarding
the New Guinea area, the Second Area Army was transferred from Manchuria on 29
October and placed in charge of defending the East Indies and the western half
of New Guinea up to 140 degrees east longitude. On 30 October, the 7th Air
Division was transferred from the Eighth Area Army to the Second Area Army, and
its headquarters pulled back to Ambon Island on 21 November.
During this time the 6th Air
Division, using what few planes it had (since the Japanese air forces had not
recovered from the August air raid), continued its mostly-defensive operations
out of Wewak. When the Allies landed at Saidor on 2 January 1944, thereby
sealing off the Dampier Straits, the Fourth Air Army launched an all-out
counter-attack against the invasion areas. By this time, however, it had less
than 100 operational aircraft, and was able to fly only 160 sorties in all on
five separate missions. Not only did this have a negligible effect on the
Allied landing force, but by the time this effort was over, the Fourth Air Army
was down to less than 50 operational planes.17 The Japanese Navy
also launched attacks against the Saidor invasion force, since the loss of the
Dampier Straits would mean that Rabaul and New Guinea would be cut off from
each other. Even when the Navy aircraft operating out of Rabaul were included,
however, the Japanese were down to approximately 100 operational planes for the
entire New Guinea-Solomons area by mid-January, which made even a holding
operation extremely difficult and indicates the desperate situation of the
Japanese air forces in this entire area at this time.
In order to improve its position,
the Army High Command decided at the end of January 1944 to move the Fourth Air
Army's centre of operations further westward than Hollandia, in order to give
its positions more depth and enable it to conduct a more flexible holding
operation. These orders were held up by Eighth Area Army, however, because it
felt that the necessary airbases in the rear, to the west, were not ready. The
High Command also decided at this time to temporarily reinforce the Fourth Air
Army with some of the Second Area Army's air units. While they would remain
under Second Area Army control, these units were to "cooperate" with
the Eighth Area Army. The units to be loaned in this fashion were the 33rd and
77th Sentai (fighters), 45th and 75th Sentai (light bombers) and the 60th
Sentai (heavy bombers). These had been slated as Second Area Army reserve, to
be based in the East Indies, but were thus committed to the front line.
In the meantime, the Japanese
Navy's air force was finally knocked out of New Guinea and the Solomons as
well. On 17 February 1944, U.S. Navy carriers launched a massive raid on the
key Japanese base in the Central Pacific, Truk Island, destroying over 200
Japanese aircraft and inflicting heavy damage. The Japanese Navy had tried to
hold out at Rabaul because its loss would threaten Truk, but since Truk was now
directly threatened, the Japanese Navy had to replace its air losses with the
only air forces available, which were those at Rabaul. Three days after the
attack, all of the remaining naval aircraft of the Japanese II Air Fleet at
Rabaul were flown to Truk, and the Japanese naval air arm's presence in the New
Guinea-Solomons area came to an end.18
On 25 March 1944, the Fourth Air
Army was transferred to the Second Area Army, and its headquarters arrived in
Hollandia. As an airbase, however, Hollandia was still not adequately prepared.
For example, facilities needed for dispersing aircraft and supplies, and for
storing supplies, were still not ready. In addition, radar and other warning
and intelligence networks were also only being prepared. The same situation
which had plagued the Japanese at Wewak thus existed at Hollandia.
Nevertheless, by the end of March the Japanese Army had managed to assemble
approximately 300 aircraft at Hollandia; of these, however, only about 150 were
operational.
In an eerie repeat of the earlier
disaster at Wewak, the bulk of Japanese aircraft at Hollandia were wiped out in
an air raid carried out over two days, 30-31 March. Over 150 planes were
destroyed on the ground. The commander of the 6th Air Division and the chief of
staff of the Fourth Air Army, among others, were relieved, because for them
this was the second time that so many Japanese aircraft had been caught by
surprise on the ground. This time, the Japanese were not given any time to
recover. On 22 April 1944, the Americans landed near Hollandia. The personnel
of the 6th Air Division, including its remaining pilots, were forced to retreat
overland to the west, arriving in Sarmi by early May, but had to leave their
aircraft behind. As a result, the 6th Air Division's remaining 100 aircraft
were lost. The division was never reconstructed, ultimately being disbanded in
August 1944.
This left the 7th Air Division, operating
at this time primarily out of bases in the East Indies. But this force, too,
was severely depleted. On 25 May 1944, it had an operational strength of only
87 aircraft.19 When the Americans landed on Biak Island two days
later, the 7th Air Division tried to provide air support for the defenders, but
since it had so few aircraft - most of which had to be used for convoy escort
and air defense missions - it was unable to do so effectively. By early July
the Biak garrison had been wiped out. This was to be the last major action in
which Japanese air forces operated over New Guinea. Thereafter, the major
action in the Pacific would shift to the Marianas, Palaus and then the
Philippines, and what remained of the Japanese Army and Navy air forces was committed
to these areas. The air war in New Guinea was effectively over, having ended in
an Allied victory.
Causes and Implications of the Japanese Defeat
There was no single, direct cause
for the Japanese defeat in the air battle over New Guinea. Since this issue has
been covered extremely well in many works in both English and Japanese, the
causes will be enumerated only briefly here.20 First of all, the numerical
advantage of the Allies was undoubtedly a major factor. While this was not a
decisive advantage until the latter half of 1943, its effect was ultimately
crucial. The Allies' aircraft strength grew steadily, while the Japanese air
forces in the area barely grew, and instead often steadily decreased, in
number. This applied to aircrews and ground support staff. The Allies, and
especially the Americans, were able to send increasing numbers of such
personnel to the front, and as the war progressed they were better trained too.
In comparison, the Japanese were hard-pressed to replace their pilots and
ground staff, and the flying and combat abilities of what replacement pilots
were sent to the front gradually decreased in quality.
The technical quality of the
aircraft used was also a factor. While Japanese aircraft in this period, especially
those of the Navy, were quite adequate (and in some respects excellent) for
certain purposes, they were not as suited for an aerial war of attrition when
compared to the Allies' aircraft. For example, Japanese machines, lacking good
self-sealing fuel tanks and pilot armor, were more susceptible to damage. In
addition, Japanese types were often more difficult to manufacture, which means
that they were not as suited to mass production as those operated by the
Allies.21
A third factor is the generally
low level of technology of Japan at this time, in comparison with the Allies.
For example, as has often been pointed out, the Japanese constructed most of
their airfields with manual labor. The Japanese Army recognized this as a
problem as early as 1942, and had studied the issue - even establishing a base
construction school in Japan22 - but little if anything had changed
by 1944. This meant that the Japanese could not construct airbases quickly
enough to maintain some semblance of parity with the Allies.
Another technological area in
which Japan was deficient, and which is sometimes overlooked, is aircraft
engine technology. To the end of the war, the Japanese were unable to produce a
reliable 1,500-2,000-horsepower engine which would also be small enough to be
used on fighter aircraft. Because of this, they were unable to equip their
fighters with pilot armor, heavier armaments and better self-sealing fuel
tanks. It is often said that the Japanese sacrificed these things because they
wanted to lighten their aircraft and improve their offensive capabilities.
While this is true, it is also the case that the Japanese wanted to install
these items, especially later in the war, but could not do so because their
additional weight would worsen aircraft performance to an unacceptable degree.
The Japanese were unable to develop an engine large enough to handle the weight
increase, so they had to leave such items off and make do with relatively
unprotected aircraft.
Individually, each of these or
any of the other factors which brought defeat to the Japanese air forces may
not have been decisive; combined, they proved to be fatal. Faced with such a
combination of negative factors, it is doubtful whether any nation could have
overcome them and attained victory.
Finally, what did defeat in the
South Pacific air war mean for the Japanese? The obvious implication is that it
exposed the Marianas, Carolines and other central Pacific islands to Allied
counter-attack, as well as the East Indies and Philippines. More importantly,
it destroyed the air forces of the Japanese Navy, and to a lesser degree the
Army as well, in terms of pilot quality. According to one estimate, the Japanese
Navy's losses between August 1942 (the start of the Guadalcanal campaign) and
February 1944 (the end of its presence at Rabaul) amounted to more than 7,000
aircraft and aircrew members.23 This was the equivalent of several
years' worth of pilots.24 Because the quality of pilot training
declined year by year, this meant that the ranks of experienced pilots within
the Japanese Navy was severely depleted by early 1944. Since the Japanese Army
committed some of its best air units to the New Guinea front, the large losses
these suffered meant that the Army, too, had lost a large number of its best
pilots.25 It is, therefore, not much of a surprise that the Japanese
air forces, especially those of the Navy, suffered such lopsided defeats in the
1944 battles in the Marianas and the Philippines.
The Japanese were able, within a
few months, to partially replenish the numbers of aircraft and pilots it had
awaiting the Allies in 1944. What they could not replace were the qualitative
losses they suffered in the South Pacific. Notwithstanding that Japanese
aircraft were becoming outmoded by 1943, right up to the war's end these could
be very effective in the hands of a good pilot. But when the quality of the pilots
declined, the result was disastrous. Without an effective air force, the Japanese
would have had an exceedingly difficult time holding off the Americans in 1944,
especially since the Americans' air forces had steadily improved, both in
quality and quantity, during 1943 and early 1944. The greatest implication of
the Japanese defeat in the South Pacific therefore may be that it eliminated
Japan's ability to achieve air superiority anywhere in the Pacific during the
remainder of the war.
© Hiroyuki Shindo
The Author
Hiroyuki Shindo is currently an
assistant professor in the Military History Department of the National
Institute for Defense Studies, Tokyo. His special areas of interest are
US-Japan diplomatic and military relations in the 1930s and 1940s, and the
military history of the Second World War.
Notes
1 Takushiro Hattori, Daitoa
Senso Zenshi (A Complete History of the Great East Asia War) (Tokyo: Hara
Shobo, 1965), p.294.
2 The activities of the Navy's air
forces based in Rabaul and Lae during the spring and summer of 1942 have been
excellently depicted in Saburo Sakai, Sakai Saburo Kusen Kiroku (Sakai
Saburo Air Combat Records)(Tokyo: Shuppan-Kyodosha, 1953) (English translation:
Samurai! (Dutton, 1957)) and many other works.
3 For a detailed account of the
process by which the Army air forces were committed to the South Pacific, see
Boeicho Boeikenkyusho, ed., Senshi Sosho Tobu Nyu-Ginia Homen Rikugun Koku
Sakusen (Army Air Force Operations, Eastern New Guinea) (Tokyo: Asagumo
Shinbunsha, 1967), pp.20-63.
4 Boeicho Boeikenkyusho, ed.,
Senshi Sosho Rikugun Koku no Gunbi to Unyo (3) Daitoa Senso Shusen made
(Equipment and Operation of Army Air Forces (3) Until the end of the Great East
Asia War) (Tokyo: Asagumo Shinbunsha, 1976), p.72.
5 Boeicho Boeikenkyusho, ed., op.
cit. Senshi Sosho Tobu Nyu-Ginia Homen Rikugun Koku Sakusen, p.155.
6 Boeicho Boeikenkyusho, ed., op.
cit. Senshi Sosho Rikugun Koku no Gunbi to Unyo (3) Daitoa Senso Shusen made,
p.75.
7 Boeicho Boeikenkyusho, ed., op.
cit. Senshi Sosho Tobu Nyu-Ginia Homen Rikugun Koku Sakusen, pp.185-90.
8 Takushiro Hattori, op. cit.,
pp.405-407.
9 Boeicho Boeikenkyusho, ed., op.
cit. Senshi Sosho Rikugun Koku no Gunbi to Unyo (3) Daitoa Senso Shusen made,
p.95.
10 Among other reasons, the
slowness with which the Army transferred its air forces around the Pacific has
been given as one of the reasons why the Army air forces were relatively
ineffective against the Allies, because that prevented them from deploying and
operating rapidly in areas where they were most needed. Masatake Okumiya,
Rabaul Kaigun Kokutai (Rabaul Naval Air Corps) (Tokyo: Asahi Sonorama, 1998),
pp.169-170.
11 Boeicho Boeikenkyusho, ed., op.
cit. Senshi Sosho Rikugun Koku no Gunbi to Unyo (3) Daitoa Senso Shusen made,
pp.93-95.
12 Ibid., p.104.
13 Ibid., p.101.
14 Ibid., pp.107-108.
15 Takushiro Hattori, op. cit.,
p.504.
16 Takushiro Hattori, op. cit.,
p.498.
17 Boeicho Boeikenkyusho, ed., op.
cit. Senshi Sosho Rikugun Koku no Gunbi to Unyo (3) Daitoa Senso Shusen made,
p.152.
18 Okumiya, op. cit., pp.366-369.
19 Boeicho Boeikenkyusho, ed., op.
cit. Senshi Sosho Rikugun Koku no Gunbi to Unyo (3) Daitoa Senso Shusen made,
p.187.
20 For example, see Eric Bergerud, Fire
in the Sky (2000), for an excellent, interesting and in-depth analysis of
the air war in the South Pacific.
21 For an analysis of Japan's
aircraft technology and its effects on the war as seen from the Japanese side,
see for example Kunio Yanagida, Reisen Moyu (Zero Fighter Aflame)
(Tokyo: Bungei Shunjyu, 1984-1990).
22 Boeicho Boeikenkyusho, ed., op.
cit. Senshi Sosho Rikugun Koku no Gunbi to Unyo (3) Daitoa Senso Shusen made,
p.135.
23 Bergerud, op. cit., pp.667-668.
24 An exact equivalent is difficult
to calculate, because the Japanese were expanding their pilot training programs
every year even before the Pacific war began.
25 According to one estimate,
nearly 800 aircraft were lost by the Japanese Army in the South Pacific.
Bergerud, op. cit., p.668.
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| US marines advance against Japanese positions with tank support, following the Allied landing on Guadalcanal in the Solomon Islands on 7 August 1942. Australian War Memorial P02018.130. |
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| Nakajima Ki-43 Army Type 1 Hayabusa fighter, codenamed "Oscar" by the Allies. Australian War Memorial P01097.017. |
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| A Japanese Zero fighter burns on the ground at Lae after an attack by Beaufighters of 30 Squadron, RAAF, on 4 March 1943. Allied aircraft focused their attacks of enemy airfields in the days after the battle of the Bismarck Sea, aiming to ensure that Japanese air power did not prevent the destruction of the targeted convoy. Australian War Memorial P01275.016. |
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| Kawasaki Ki-61 "Tony" fighter. Australian War Memorial 129685. |
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| Kawasaki Ki-45 heavy ground attack and night fighter. Known as Toryu (dragon killer) to the Japanese, it was dubbed "Nick" by the Allies. This machine is in American markings, having been captured and restored for technical assessment purposes. Australian War Memorial AC0190. |
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| Dagua airfield near Wewak, New Guinea, after its capture by Australians in March 1945, showing some of the more than 100 Japanese aircraft found wrecked there. Australian War Memorial OG2688. |
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| Hollandia airfield under attack by the US Fifth Air Force in April 1944, showing the complete disregard shown by the Japanese for aircraft dispersal. Australian War Memorial 127620. |
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| Japanese airstrip at Lae, New Guinea, under attack by Australian and USAAF bombers. |
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| L-5 aircraft of the 25th Liaison Squadron in New Guinea. In addition to their liaison duties, sergeant pilots of the “Guinea Short Line” performed such varied missions as rescuing downed fliers and guiding fighters to concealed jungle targets. |
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| Kawasaki Ki-48-II, Japanese Army Air Force, Dagua, Papua New Guinea, circa March-May 1945. Australian soldiers check out damaged Japanese aircraft at the Dagua airstrip captured in the Aitape-Wewak campaign of World War II. |
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Japanese planes destroyed in the attack on Hollandia.
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| An A-20 of the 389th Bomb Squadron, 312th Bomb Group, emerges from a plume of smoke following an air strike on New Guinea. |
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| The shadow of the A-20 Havoc tells the story of a low-level attack run on a Japanese aircraft in Lae, New Guinea. |
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| B-25 medium bombers leaving installations aflame in the Wewak area August 13, 1943. |
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| A-20 Havoc aircraft of US V Bombing Command targeting Japanese airfield of Ki-48 bombers, at Hollandia, New Guinea, 1942. |
