Winged Victory
for the Allies becomes more likely
While Germany Waits

by T P Wright
Vice-President of Engineering
The Curtiss-Wright Corporation
Hitler missed his chance at Munich. Then he had two and one-half times as many airplanes as the Allies. The tide is now turning and Germany's chance for success grows steadily less as, month by month, the Allies close the gap. British and French production rate, including planes from the US, actually passed the German monthly rate last fall, but Germany will still lead in total numbers of available planes until early in 1941. Outcome of the entire war hinges on the questions discussed in this able analysis of Allied vs German airplane production.

In June 1939 Aviation magazine published an article of mine entitled "America's Answer," in which was discussed the capacity of our aircraft industry to meet the needs of national defense as advocated by the President and authorized by the Congress. The conclusion was reached that the industry would be capable of meeting the delivery schedules required with but a ten per cent expansion in floor space. It was assumed that export orders would continue in quantities that approximated those then current and I hedged only to the extent of stating that "in case a war should start, all bets are off."

Then in September, the war in Europe broke out. Orders poured in from abroad, and as a consequence, there has been an expansion in the industry of approximately 40% in floor space as against the ten per cent previously assumed. As the capacity and output of our expanding airplane industry may have an important bearing on the outcome of the war, it appears desirable again to survey the production situation at home with particular reference to shipments which will be made abroad and, as well, the resulting air strength of the belligerent countries.

So much of a conflicting nature has been written of late concerning the air power of the nations at war and our capacity to deliver planes to the Allies while we at the same time build up our own air forces, that considerable confusion exists. Practically every new issue of current magazines and periodicals, both in trade journals and in the popular magazines outside the industry, contain estimates of monthly production rates and total air strength of the countries at war. There are frequent discrepancies between these estimates and they are not always consistent in their reasoning. So, one object of this article is to arrive at probable present air strengths, accomplished by building up through the past several years from rates of production on which quite accurate information is available. The figures obtained have been checked against the most logical of the current estimates and modified where such considerations have warranted it. The curves here shown are the result.

Rate of production

A fairly good conception of rate of production of airplanes of the countries at war in Europe was obtained by the writer during extensive visits to airplane and engine factories in England in 1934, 1936, 1937 and 1938; in France during 1934, 1936 and 1938; and in Germany during 1936. Numerous discussions with others in the industry who have traveled abroad have added further information.

Of course, censorship has for some time prohibited the printing of direct information on actual rates of production. Frequently, however, information on floor space, labor force, appropriations, and other such data has appeared and has made possible the working out of production rate figures by the use of constants developed on the basis of known actual practice in this country. This was the method used in the June 1939 Aviation article and it is desirable here to recapitulate some of these constants and the assumptions on which they are based, re-checked in the light of the experience of the past nine months. These data appear in Table 1.

Miscellaneous Constants For Computing
Aircraft Production Values And Quantities
Engine &
ConcentrationSquare Feet per Man100  204  
Money ValueDollars per Sq Ft per Year56  49  
Money ValueDollars per Man per Year5,600  10,000  
Money Value
(Approx Average)  
Dollars per Pound 7.57.5
Weight ValuePounds per Sq Ft per Year7.56.5
Weight ValuePounds per Man per Year750  1,340  


It is assumed —

  1. — that capacity conditions, which are approximately two full day shifts, maintain. (This actually equals about one full day shift plus three-fifths day shift on first night shift and two-fifths on second.)
  2. — that all-metal type of airplane structure is used.
  3. — that average size of airplane orders are lots of 400; and that engine and propeller factories are operating near capacity.
  4. — that a profit margin of 10% is realized.
  5. — that labor average rates are:
  6. — that airplane structure weight is equal to gross weight less useful load and less weight of engine, propeller and instruments.
  7. — that floor space includes stockroom but excludes office space.

As a sample of the method used, the following three examples are given. It is obvious that this method can be extended so as to shed light on the basic problem as each new piece of factual information comes to hand.

"Examples" illustrating method

"A"— How near is the American Aircraft Industry to its capacity?


With about 8,250,000 sq ft of floor space and 60,000 workmen, we have 137.5 sq ft per man and therefore are 73% capacity, which is estimated to be 100 sq ft per man.

Engines and propellers

With about 3,500,000 sq ft of floor space and 16,000 workmen, we have 218 sq ft per man and therefore are 94% capacity, which is estimated to be 204 sq ft per man.

"B" — What should be our yearly dollar value of production? (using present labor force and facilities, and several of the "constants" of Table 1).


$5600/man/yr × 60,000 workmen = $336,000,000 or, using another basis as a check, $56/sq ft × 8,250,000 sq ft × 73% Capacity = $336,000,000.


$10,000/man/yr × 16,000 workmen = $160,000,000 or, using another basis as a check, $49/sq ft × 3,500,000 sq ft × 94% Capacity = $161,000,000. Total = $496,000,000, which checks with several current estimates.

"C"—What is the Current Production Rate of Airplanes in Germany?

When averaging several sources one obtains a figure of 400,000 men in the German aircraft industry, including the main companies with the smaller subcontracting units which feed parts into them, and including airplane, engines, propellers and instruments. In our industry we have for these items about 85,000 men (assuming 9,000 for instruments) which would total 100,000 after adding for subcontracting outside the principal companies of the industry. We might then expect Germany's production rate to be 400,000 + 100,000 = 4 times our own. But her production lots average greater than ours, perhaps twice as many (800 vs 400) making possible a greater output per man. Using .90 for this factor we obtain 4 + 90 = 4.44 times our output which appears to approximate the facts.

Analyses of this kind are admittedly approximations but when figures obtained by many different methods of approach are checked and re-checked, and when a fair degree of judgment is exercised, final answers near the truth should result. One source of error which may occur through using this method of applying "constants" is failure to be on guard against violation of assumptions on which the "constants" of Table 1 are based. For example, assumption 3 presupposes production lots of 400 as an average; there are many factors involved in determining rate and cost of production as size of order changes, such as degree of tooling, number of changes from a model previously manufactured, extent of previous manufacture of similar models and general morale efficiency of the workers. As a rough average for analyses of this kind, it has been found reasonable to assume a factor of .90, as used in example "C" above, to take care of a quantity other than 400 in a given lot. This factor means that every time the quantity in production is doubled, the unit cost will be only 90% as great as in the smaller lot.

There are many things to consider when estimating the rate of delivery which it may be anticipated the factories of this country can make to the Allies. For instance, great care must be taken when making a check of quantity using the money value of orders as basic data, since information frequently is not available on the additional price paid in order to take care of accelerated deliveries, which involves payments for plant expansion necessary to step up production. Also, profits may differ from those of the basic assumption.

However, sufficient information is available to permit making a good estimate of export deliveries, based on current orders and on expansion of facilities now under way. Deliveries of planes and engines on present orders extend into 1941. Further acceleration of delivery of these or of new orders will require extensive added expansion of their facilities.

The curves

After due consideration of the information from the many sources previously mentioned, and the need for caution in interpreting such data, the curves of Figure 1 have been produced to show the monthly deliveries that have maintained since January 1936, and projected from the present time through 1942. The rather constant increase in rate of production of Germany since 1936 with her substantial lead over the Allies at that time, is noteworthy. The slow start which the Allies and the US made and the relatively small production extending well into 1938, coupled with rapid increase of rate of production in England subsequent to 1938 are also important. Here I would like to emphasize the magnificent comeback that England has made in the air after a very slow and muddling start. One should also note the rapid increase in assistance to the Allies from the United States which may be expected to maintain from now on, even while building up the rate of delivery under our production program as required to meet our own Air Force expansion needs. But, compared to England and Germany, our production is still small. It becomes larger as time goes on and will become of extreme if not deciding importance eventually, morally as well as materially.

Figure 1
Figure 2

Growth of air force

The method used to obtain the curves shown in Figure 2 is the following: A start is made in January 1936 with an estimated air strength for each country. Information was not withheld at that time as it is now so that the relative strength and, to a somewhat lesser degree of accuracy, the actual strength could be determined. Then, the strength for each succeeding year is estimated by increasing for that year, each country's air force by the amount obtained by integrating the curves of Figure 1 and then reducing by an amount estimated to take care of obsolescence and wastage due to crashes or other causes of loss. It has been found that in this country, the yearly depreciation of the air force is approximately 22% in normal times, probably somewhat less during a period of rapid expansion. In determining depletion for European countries during the period 1936 to date, varying rates of depreciation were used, depending on particular circumstances which were found to maintain as regards rate of obsoleting equipment, rate of training and probable resultant crashes, both in training and service. The figures average from about 25% per year in 1936 to 45% per year by January 1940. This, it should be noted, is a monthly rate of depreciation of from 2% to about 4%. At the present time, March 1940, with relatively minor air activity, it is not believed that the depletion is more than 5% per month, judging from the published losses of the various belligerents, coupled with the other factors cited above.

It should be noted that the curves of Figure 2 cover total planes of all types, including first-line, reserve, cooperation, and training. In using the method herein described for obtaining air power, total labor force or square feet of floor space are important factors.

It is therefore necessary to plot total air force strength including all types of planes, as stated above. However, as shown on Figure 2, the proportion each class of plane bears to the total approximates the percentages shown, with admitted variations from these amounts, depending on the special emphasis which a given country may currently place on building up its various branches: first-line, reserve, cooperation types (reconnaissance, observation, and cargo), or training. For example, Germany, an aggressor, emphasized bombers; England, a defender, pursuits. During certain periods of expansion, trainers must be emphasized. Also, the proportions of first-line to reserve are affected by availability of pilots. It is believed, however, that the percentages given will not vary for any country by more than 15% of the values shown.

The curves for total air power have been extended beyond the present time, showing a tendency to flatten out, based on similar falling-off in increase in monthly delivery rates as the estimated capacity of the country involved is approached. Such capacity may be limited by personnel, by machine tool equipment, by raw materials supply, or for other reasons.

Effect of "total" war

Shown in dotted lines on Figure 2 are the effects on the total air power strength of the Allies and Germany which will maintain in the event of a "total" war in the air taking place. These curves have been derived by assuming continuing rate of production as given in Figure 1, (as it is impossible to guess even the approximate falling off of production that might result from bombed aircraft factories), but assuming destruction of planes in service at the rate of 25% of total strength per month. This 25% rate of depletion, it should be noted, is at the low limit of plane casualties frequently forecast as probable in the event of real air warfare, as such estimates have ranged from 30%, put forward by several English authorities, through 50%, or even 80% mentioned by certain German and Italian writers. I am inclined to doubt that anything like these last mentioned will maintain, particularly when considering the effect on air strength which results. Furthermore, even in the event of a "total" war, there may be reluctance on the part of Germany to dig too deeply into her oil, iron and aluminum reserves. Twenty-five per cent of Germany's air force was used in estimating the reduction in strength of the Allies as well as of Germany. This is the most pessimistic point of view (from the A1lies' standpoint) as, if Germany is the aggressor, she will probably lose far more planes than the defending Allies. When using 25%, as stated, an interesting point which these curves portray (assuming that the "total" war starts this Spring) is that the air strength of the Allies will exceed that of Germany during the last half of 1941, although towards the end of 1940, there will be a dangerous disparity between the two air forces in favor of Germany. Strangely enough, in the event a "total" war does not start this Spring, the relative strengths of the belligerents in the air will become equal only a couple of months earlier in 1941!


Comment on this admittedly important subject will be restricted to the statement that in the writer's belief, quality of equipment is and will remain substantially equal. As the war proceeds, one belligerent or the other may, for a time, excel in some particular branch as, for example, it is believed the Allies now excel in pursuit aviation and Germany in bombardment (even this latter point might be questioned, particularly if proper credit is given to the highly developed and effective power controlled, rear-firing gun turrets with which many British bombing planes are equipped). It is not believed, however, that superiority in performance of equipment will so predominate on either side as to make this the determining factor. No one who has inspected German equipment and German research laboratories, and is aware of German general engineering and scientific ability, can believe the quality of her products from the performance standpoint, is likely to be greatly exceeded. There is the possibility that German quality may suffer as the war goes on, due to the necessity of using inferior materials caused by curtailment of supply, although probably not for some time to come. Similarly, one cannot feel that the Allies will trail in quality after viewing such notable English aircraft equipment as the Spitfire and the Hurricane or knowing of the more recent developments in France, or of the excellent service experience in the hands of the French rendered by planes delivered from the United States.


If we may assume then, that the curves presented are essentially correct, or at least within reason, it is now timely to analyze their meaning. Referring to Figure 2, we see that equality of air strength maintained in December 1936 may be expected again to maintain in the second half of 1941. Between 1937 and the start of the war, there has been a substantial and important disparity in favor of Germany. In February 1938, the present Allies had but 50% of the air strength of Germany; by September 1938, the greatest difference of the whole period existed, Germany having about a 2½ : 1 superiority — and this was the exact time of Munich! I feel certain that this superiority is the true explanation of Munich.

Military history has indicated that it takes time for each new offensive weapon to bring out an antidote of defense and the past four years have shown the manner in which unscrupulous nations can make use of any supremacy which they may temporarily gain. Such superiority in the air on the part of Germany has brought about the Austrian anschluss, Munich and the rape of Poland. Italy demonstrated it earlier in Ethiopia, then Japan in China and now Russia in Finland. But in World War II in Europe, defense is now catching up, partly through improved anti-aircraft, but more particularly because of approaching parity in the air itself.

By the start of the war, the Allies had improved production so much that their combined air force was 60% of that of Germany and the time had passed when it could be anticipated that an aerial Blitzkrieg on the part of Germany would be successful. A superiority of two to one might make an air Blitzkrieg successful but not when ratios are much less than that amount, as it must be remembered that there is an inherent advantage for defense, particularly in the air. At the present time, this relationship favors Germany by about 1.3 : 1, with the gap rapidly closing.

This analysis is based on the present line-up of the nations at war. No mention has been made of the possibilities of the scales being weighted one way or the other by the entry of Russia or Italy into the major conflict. It seems to me doubtful, although admittedly unpredictable, whether these countries will engage actively and, in the case of Italy, there is further substantial doubt as to the side with which she will cast her lot. Then there are balancing possibilities which cannot now be appraised with certainty, such as Scandinavia, the Low Countries, the Balkans, and Turkey.

Certain it is, however, that Air Power has acquired determining importance in warfare because of its dual role: it is the eyes of the army and navy; and it possesses tremendous striking power of its own. It seems likely therefore, that the eventual outcome of the war will be largely affected by the relative strength in the air that each side can muster. I feel that Germany's past supremacy and present small superiority in the air will be overcome by the Allies. The curves shown should approximate the situation. Assuming substantially equal land forces and land defenses; and continuing Allied supremacy on the sea; and economic superiority for the Allies in access to world markets and in financial means of exchange; then, once air equality is attained, the outcome will not remain long in doubt. This time should arrive late in 1941 or early in 1942, and with it, Allied victory.

Total Air Power
First Line………30%
Training……… 30%
Above proportions are approximate,
varying for different countries and at different times

The world has had to relearn this lesson the hard way: policy must always be backed by strength. This holds whether international affairs fall into the scheme of power politics or collective security. Collective security, in the form of the League of Nations, was tried after the last war. It proved insecure and failed since collective strength was not behind it. Realizing the determining importance of Air Power, Germany secretly started her air rearming. She built up an efficient industry and then openly extended her air force and by threat of its use, acquired much of what she wanted. If the world has learned the lesson sufficiently well, then after this war we may possibly hope to look forward to a more effective collective security. When backed by overwhelming air power, some future federation, or union, or league will possess a means of keeping the peace far superior to any yet devised. Then the airplane will assume a new dual role in civilization: the most rapid means of transportation, for bringing people closer together, and the guardian of peace for enforcing and insuring success of the next form of collective security.

This article was originally published in the April, 1940, issue of Aviation magazine, vol 39, no 4, pp 32-33, 102, 106, 109, 112, 115.
The original article includes a small portrait of the author, 7 photos and the two graphs and two tables above.
Photo subjects include Me-109, He-112 (2), Blenheim, Wellington, Hawk, Spitfire.
Photos credited to Acme, European.