During the past summer, there were several distinct lulls, mostly short but some quite long, in Jap air operations in the South Pacific. On six days during July, Japanese planes made no appearance whatever over Allied positions in the Solomons, and on eleven days, over Allied-held portions of New Guinea. In the first week of September, Jap planes were conspicuously absent from their own parts of eastern New Guinea as well: Liberators and Mitchells raiding Madang Sept 3 encountered only one Jap throughout their journey, and that one was on the ground. These developments have given rise to the belief that Japanese air power has finally begun to toboggan toward annihilation. The fact is, however, that our Pacific enemy is very nearly holding his own in the air and that we have made only a beginning at destroying him. The impression given by a superficial glance at events in the South Pacific is misleading.
To begin with, Jap losses in the Solomons-New Guinea area are actually no less this year than last. Thus, there is no statistical evidence of an overall decline in their activity in that theater, notwithstanding the lulls. Second, even if it is so declining, it is not conclusive, for in the South Pacific the Japanese are fighting a series of delaying actions to which they are committing only limited forces. And finally, Jap air strength has steadily increased in recent months in another theater, the Chinese, where the Japs seem to be preparing a major effort to knock out Gen Chennault's small but troublesome Thirteenth US Air Force.
The erroneous view of declining Japanese power in the skies stems equally from other facts besides the South Pacific lulls, similarly misinterpreted. One is the appearance of not a few enemy biplanes in the sky over the Central Solomons, especially in the days immediately following the gigantic air battles the day we landed on Rendova, which cost the Japs 110 planes. It should be remembered, however, that the Japanese make regular use of combat biplanes some of their models have quite high performance. As for the obsolescent types which also appeared, the Japs frequently suffer from local shortages of up-to-date craft because their ships are extraordinarily difficult to maintain. In the interests of cheap and light construction, the Japs have resorted to many shortcuts such as placing wiring directly in the skin instead of in conduits; repairs to such wiring are a major operation. Consequently, at any given moment, a quite large percentage of Japanese planes are on the ground. But such local shortages do not necessarily mean a general shortage.
Another reason for our mistaken impression of Japanese air power is that most of us are still underestimating our Pacific enemy's production. Even today, the majority of "authorities" believe that the Japs are turning out only 400 to 600 planes a month, including training and utility as well as combat craft. Actual production is a minimum of 800 a month and may well be considerably higher. The low production estimates exaggerate the significance of the losses Allied forces are inflicting. Considering the fact that by far the greater portion of Anglo-American air strength is concentrated on the European front, these losses are impressive, but they are not decisive.
In the 20 months since Pearl Harbor, British, Australian, American and Dutch battle reports chronicle the destruction or capture (only an insignificant proportion of the latter, of course) of about 9,000 Japanese planes altogether (allowance is made for duplications among the Allied communiques). US Army and Navy forces in the Pacific, from the Dutch Indies around the Jap arc up to the Aleutians, accounted for 3000-3500 of these. American forces in India claim another 500 and in China, 600, and the American-manned AVG (the Flying Tigers) accounted for more than 400. Up to the end of June, the RAF and RAAF had destroyed another 4000. The Dutch shot down about 200. Thus the 9000.
But these are not all of Japan's air casualties. In Europe, experience shows that enemy losses are approximately double our claims for every plane we, the British and the Russians claim, there is a plane shot down and unreported. The Nazis lose many in weather or other accidents or from battle damage not severe enough to down the plane on the spot but too great to permit salvage. Owing to the fact that operating conditions in much of the Japanese war theater are better than those found in Europe, unreported Jap losses are probably proportionately smaller than the Luftwaffe's. But they are at least half as great as the reported Jap casualties. Hence the Japanese have lost to date a minimum of 13,000 combat craft, or nearly 700 a month.
This figure can be confirmed by another method of calculation. The life of the average military plane is approximately five months. Since there are long lulls in the war with Japan, the life of the Jap combat craft is perhaps six months. (If Jap operating and maintenance techniques were equal to ours, it would be seven or eight months.) In other words, the Japanese air forces lose about one-sixth of their number of planes each thirty days. At the beginning of the war, according to Russian estimates (the Red Army was then much more accurately informed on the Japanese than we were), the Japanese had about 4000 combat planes. On the one-sixth a month depreciation basis, such a force's monthly losses would be about 700 planes.
If Jap production were only 5000 to 7000 a year or 400 to 600 a month and some of the erroneous estimates are even smaller the Japanese air forces would already have ceased to exist. For it would have a net loss of 200 combat craft a month, or a total of 4000 in the 20 months of Pacific war. Even on the basis of the 450 casualties a month claimed in Allied communiques, the low estimates of Jap production would mean a Jap air force very much weaker than it actually is. It is possible that Japanese losses do exceed replacements, but by no more than a squadron or two in the average month. The first-line strength of the Japanese air force is within 500 planes of what it was on Dec 7, 1941.
So far as can be determined, the Japs have made no mass use of air transport. Consequently, the proportion of non-combat to combat types in (their aircraft output is likely to be smaller than ours perhaps as low as one-fifth. Thus, a reasonable figure for overall Japanese production is 800 aircraft a month. It should be emphasized that this is a minimum figure. It should also be noted that Japan has had sufficient production resources to put into production during the last year a much improved model of fighter, the Type 3, which has just appeared in the northern Solomons. The Type 3 looks a good deal like a Zero with an in-line instead of a radial engine, but it is much more substantially built and is not only fitted with much heavier armament, but with armor and leak-resistant gas tanks in addition.
Although she has been able to make good most of her plane losses, Japan, however, has not been able to replace the live or six aircraft carriers we have sent to the bottom. A little over a year ago, Domei, the Japanese news agency, announced that Tokyo would commission four new carriers in 1942. These were supposed to be repeat Ryukakus (we sank the Ryukaku in the Battle of the Coral Sea) or converted carriers built on the hulls of the famous 15,000-ton Jap pocket battleships which have never appeared or else extraordinary cruiser-carrier hybrids known as the Tsugarus. Japan's known difficulties in securing steel (her huge conquests have not added to her inadequate coal or iron resources) make it improbable that more than three carriers have been completed since the beginning of 1942. So the Japanese navy has only seven in place of the ten carriers it had 20 months ago. These the enemy is husbanding with such care that much of their value is destroyed. Jap carriers have not been in action since mid-fall of 1942.
In one sense, the tide has already turned sharply against our foes. In the months after we moved into Guadalcanal, Jap planes were constantly on the tactical offensive, carrying out daily harassing attacks on our forces. This year they have made less than one-fourth as many such sorties. Their activities have been confined principally to defense against ever increasing assaults we have mounted on their various island positions. Thus, the immense majority of the 300 planes destroyed by Allied flyers in New Guinea in August were over or on the ground at Jap airports. The majority of Jap losses in the Solomons after mid-July were of the same kind. Only in China are the Japanese carrying out serious offensive air operations. This gain, however, is due more to the reinforcement of Allied strength than to rapid disintegration of enemy air power. Most of the job still remains to be done.
This article was originally published in the October, 1943, issue of Air News magazine , vol 5, no 3, pp 24-25 , 56.
The original article includes 8 small photos of various Japanese planes.
Photos credited to Air News, US Navy, Wide World, Acme.
NOTE: The "Type 3" mentioned would seem to be the Tony. JLM