Chapter 10: The Production Record
THE United States produced almost 300,000 military aircraft in the 62 months between 1 July 1940 and 31 August 1945. During the same period it turned out 802,161 aircraft engines of all types and 807,424 airplane propellers. The total airframe weight, including spare parts, was 2,859,098,000 pounds. The cost of this aircraft program was almost $45 billion, or 24.5 per cent of the total American munitions program of $183 billion. Between 1940 and 1944, when peak production was attained, aircraft manufacture was transformed from a handwork to a mass production industry. During 1940, when the industry was just beginning its expansion, it produced approximately 13,000 aircraft, less than half of them military. In 1944 it turned out more than 96,000 military planes, very nearly 16 times as many as in 1940, and these were generally much larger and much more complex than those of the earlier year. Measured in terms of airplane weight, production rose from 24,600,000 pounds in 1940 to 1,101,116,000 pounds in 1944, a total 45 times as great. Military engine production increased from less than 16,000 engines in 1940 to 256,912 in 1944, more than 16 times over. If the total horsepower of the engines produced be taken as the index, the comparative figures stand at approximately 16,000,000 in 1940 and 431,282,000 in 1944, an increase roughly twenty-seven fold. The monetary value of the finished product increased 30 times over – from approximately $552 million in 1940 to $16,745 million in 1944.1
The floor space devoted to aircraft manufacture increased during these years perhaps as much as twelvefold, and the manpower employed perhaps sixteen fold.2 A widespread use of subcontracting makes it difficult to get more exact figures,* but it is clear enough
* The floor-space increase for prime contractors was something like eight or nine times and the labor increase about ten times. But the increase in subcontracting made much additional floor space and manpower available, so that the over-all increase was probably as indicated above.
that new techniques of production played a more important part than did any other factor in making possible the remarkable record achieved.
The Assembly Line
Prior to 1939 there had been little reason for either airframe or engine manufacturers to use mass-production methods, for both military and commercial orders remained so small that an order for fifty planes rated large. Not only was the volume small, but frequent adjustments of design, even on a particular model, denied the aircraft manufacturer an opportunity to follow the pattern set by the automotive industry, where models could be frozen for at least a year of quantity production. If the aircraft industry showed the highest quality of craftsmanship in the work of its individual machinists, it also had failed to exploit fully two of the distinguishing features of our industrial society – the machine tool and the interchangeable part. Parts were usually run off in “job lots,” and little attempt was made to break assemblies down into subassemblies. The parts were gathered in one place where the airplane was assembled from the floor up by highly skilled mechanics who made necessary adjustments as they built.3
By 1940 national policy demanded production in quantity as well as quality. Aircraft manufacturers, who recognized the need for a change of method if the set goals were to be met, sought first to persuade the government to freeze its aircraft designs. They pointed out that mass production could be attained only if planes and parts were standardized to permit scheduled production at steady rates.4 Though it seemed to some authorities in the War Department, among them Lovett, that the industry lacked a desirable interest in improvement of production methods,5 the Air Corps gave close attention to the possibility that its program of expansion might be built around a few models of proved design. But this hope proved to be an illusion. Since the AAF fought in so many theaters under such widely varied climatic and tactical conditions, it was often necessary to incorporate in any given model many changes dictated by differing requirements in the several theaters of war. Experience showed that the solution lay in full use of mass production of certain basic models which could then be adapted in AAF modification centers to the peculiar needs of the various theaters.
It took time, but by 1944 constantly moving assembly lines, equipped with a variety of precision tools, many of them newly developed, provided a steady flow of parts and subassemblies which merged into assembled airplanes at rates measured in hours and minutes rather than days or weeks.6 Among the earlier assembly lines was the one which began operations in the North American plant at Dallas in May 1942. The most ambitious of early efforts to mass-produce airframes was made, as might have been expected, by an automobile firm: Ford made the attempt on a grand scale at Willow Run, establishing a full-blown B-24 assembly-line organization from the very beginning. of operations. In spite of its great resources, however, Ford was later than most other airframe manufacturers in getting into production, encountering many difficulties in adapting automotive production methods to airframes and requiring more help from the aircraft industry than it had originally sought.7 Nevertheless, it ultimately succeeded and in 1944–45 became the prime example of mass production of aircraft.
Assembly-line production methods permitted the use of large pools of unskilled labor which probably could never have been trained in time, if at all, to perform the varied skills required of the 1939 airframe or engine plant worker. Automotive precision tools made possible a new degree of specialization and substantially increased the product of the individual worker. The Aircraft Resources Control Office found that the individual employee’s output of airframe pounds per working day rose from 1.05 in July 1941 to 2.70 in July 1944. At the same time, the man-hours spent in production of parts, subassemblies, and whole aircraft declined steadily, even after full production had been attained. The measure of the progress achieved is suggested by the following table of the actual man-hours required for the manufacture of complete airframes, subcontracted work and the installation of engines, propellers, and equipment being included:–8
| Plane | Company | Jan. 1943 | Jan. 1944 |
| B-17 | Boeing at Seattle | 35,400 | 18,600 |
| B-24 | Consolidated Vultee at San Diego | 24,800 | 14,500 |
| B-25 | North American at Inglewood | 14,800 | 10,700 |
| C-46 | Curtiss at Buffalo | 113,000 | 49,500 |
| C-54 | Douglas at Santa Monica | 142,100 | 62,600 |
| P-38 | Lockheed-”B” at Burbank | 14,800 | 9,600 |
| P-47 | Republic at Farmingdale | 22,200 | 9,100 |
Though the Air Corps and the Navy were never able to standardize their requirements to the full extent desired, they did make a helpful contribution to the improvement of production methods. Navy carrier planes could not be built to the specifications fixed for AAF aircraft, but many of the parts – bolts, nuts, pipe fittings, or pressure pumps-and much of the equipment – engines, propellers, and communications devices – used in the planes of the two services could be and were standardized. In response to pleas from the manufacturers and to an increasing sense of the necessity on the part of service agencies,9 the Joint Aircraft Committee, after its establishment in September 1940, conducted a continuing investigation of opportunities for standardization of equipment employed by the two American services and the British.10 British agencies cooperated by limiting their purchases to aircraft types used by the American services and by restricting to a minimum the special refinements desired by the RAF. It was easier to handle the problem for relatively simple training or cargo planes than for more complex combat types;11 nevertheless, the effort to provide the maximum of standardization was continuous.
While the JAC and other agencies sought earnestly to reduce the differences among the aircraft and the items of equipment being produced for the air services, both technological development and tactical experience were pulling in the opposite direction. From the theaters of combat came a steadily mounting demand for modification of planes and equipment to meet the changing requirements of battle. It was a plea, of course, that could not be ignored, but the concurrent demand for maximum production was no less compelling. The answer to this dilemma came partly from the long experience of the Air Corps as a participant with the manufacturer in a common experimental venture. From the very infancy of the Army air arm, flyers, hoping for better performance, had been accustomed to tinker with and adjust their planes. Such ingenuity had not infrequently led to modifications incorporated by manufacturers in new models. It was but natural for those who had grown up with the Air Corps and who found themselves confronted in battle with a need for more range, more armor, or greater firepower, to turn first to their own resources and to get the desired change made through their own depots or even by their own ground crews. If the commanding general happened to be an engineer, as was Kenney in the Southwest Pacific, the number of attempted modifications of standard models might reach very impressive
proportions indeed.* In every theater the normal depot work of repair and maintenance was supplemented by a growing load of modifications in the continuing race to keep equipment abreast of the demands of battle. By 1944 the air service organization in ETO was devoting the greater part of the resources of two huge base depots – employing all told some 28,000 men-to aircraft modification.† Production of standard models thus could be kept rolling with some assurance that their adaptation to particular requirements would be provided for in the theater.
But this practice alone could not have sufficed. The number of modifications required – some small, some large – grew steadily. To relieve the pressure on the limited resources of the overseas air forces, it was desirable to incorporate the modifications as quickly as possible into the standard model produced by the manufacturer. Two factors, however, made this difficult. One was a consideration of time; major changes in a model, or even the incorporation of a good number of minor changes, could involve a serious delay in production with results affecting plans for the equipment of combat units. Moreover, requirements varied from theater to theater, so much so as to make it virtually impossible to introduce every needed modification into production models. The answer to these difficulties was found in the establishment of special modification centers in the United States.
The original impetus to set up these modification centers came from General Brett who, during a visit to the United Kingdom in the summer and fall of 1941, learned that the British had found it necessary to undertake a good many modifications on American-built planes, with a resultant strain on their depot facilities. He accordingly recommended that every effort be made to incorporate the maximum number of modifications required by the British before the planes were shipped to England.12 This recommendation came at a time when there was already much concern over delays in production that were attributed to frequent changes of design,13 and special modification centers seemed in the circumstances to offer a logical solution.
The Materiel Division proposed the establishment of ten modification centers,14 the first of which began operating at Cheyenne, Wyoming, late in January 1942. Originally, it was expected that the aircraft manufacturers would each operate the modification center for
* See Vols. IV and V, passim.
† See Vol. II, pp. 628-30, 661-63.
its own planes, but in this hope the AAF was destined to disappointment. Engulfed by the mounting demands for expanded production, the aircraft companies were in no position to take on the additional burden. Consequently, the AAF turned to the commercial airlines, whose maintenance shops contained the necessary facilities.15 The American, Chicago, Mid-Continent, Northwest, Southern, and United airlines were among the first to respond to the AAF’s appeal. The B-25’s used in the Doolittle raid on Tokyo in April 1942 had been modified for their special mission in February by the Mid-Continent Airlines at Minneapolis, one of the first companies to get a modification center into operation. By July 1942 twelve centers were in operation, and the grand total ultimately reached twenty-eight, though there were never this many in operation at any one time. To provide floor space and necessary facilities, the government ultimately spent $100,000,000 on twenty-one centers, eighteen of them operating exclusively for the modification of AAF-type planes. At the peak of operations, the floor space had reached 5,000,000 square feet and the employees totaled more than 45,000 persons.16
Even so, demands for modification swelled to almost unmanageable proportions as the war progressed. In addition to the effort to keep up with the requirements of overseas air forces, the Navy, and foreign recipients, the modification centers also installed certain standardized items of equipment ordered by the Joint Aircraft Committee but not yet introduced into the production line; made changes found necessary for the safe and efficient operation of the plane; and attended to such maintenance work as might be necessary when the plane was delivered to the center. While getting the new centers into operation, the AAF leaned heavily on its own air service depots, which during the summer of 1942 were modifying planes at the rate of 500 per month; at the close of 1943 the Air Service Command found that modifications performed in its repair shops still represented 40 to 50 per cent of the work done. Attempts during that year to reduce the load by establishing two standardized sets of requirements for modification – one for planes assigned to European theaters and the other for aircraft scheduled for service against Japan – proved none too successful in the face of demands that continued to vary from theater to theater.17 Not until the summer of 1944, when production had reached a point offering assurance that established requirements would be met, was it possible to take the risk of delay in production schedules by
making more modifications in the assembly line. In the preceding spring the responsibility of the Air Service Command for modifications had been limited to special projects, in the hope that a “single acceptance” policy – which is to say that modifications would be incorporated during production and before acceptance of the plane-might eventually be achieved.18
The record makes it clear enough that the advantages of mass production in the aircraft program were gained only at the cost of a heavy burden of modification, and that at any time before 1944, that burden could have been substantially reduced only through unacceptable delays in production. Modifications ranged from the simplest to the most complex operations. The man-hours expended on a plane might vary from as few as a dozen to many hundred, with the heavy bombers requiring the fullest attention. The most common modifications involved the addition of armor and guns or communications and target-finding equipment, with the last changing very rapidly and becoming increasingly vital to operations. It might be necessary to alter the design and equipment of a B-24 for unanticipated service against submarines, or to modify another type for photo reconnaissance. Some planes required special protective devices against desert sands, others against the cold weather of arctic regions. Often the problem was to find room for more fuel, or for more bombs. With the B-29, which preempted much of the modification capacity during the latter half of the war, modification centers worked hard to take the “bugs” out of a plane that not only was hastily produced but in a very real sense had its service testing in combat.† The job usually was to add some new feature of design or equipment, or to make adjustments of existing equipment, but there were also instances in which devices incorporated in the standard model had to be removed before shipment to particular theaters. When hostilities ceased, only those modifications necessary for safety of operation or for experimental purposes were continued, and the responsibility for these fell now to normal agencies as the special centers were closed.19
At the other end of the production line the use by prime contractors of subcontracts with other firms for the production of special parts,
* By the end of August 1944 this policy had been agreed upon with the manufacturers of the A-20, B-24, B-25, B-26, and C-47.
† The center at Birmingham, employing 8,000 to 9,000 persons, devoted most of its capacity to the B-29 during this period.
equipment, or even subassemblies, served in important ways to keep assembly lines moving. A practice familiar enough in other industries, the aircraft industry, as has been previously noted, had had little cause to try it and at first showed a disinclination to test its advantages. Some of the smaller companies, notably Grumman and Brewster, turned to subcontracting as early as 1939, but the larger firms continued to fear the building up of potential competition, a fear reflecting the sharply competitive character of the aircraft industry during the interval between the two wars. Although the prewar plans of the Air Corps for industrial mobilization had assumed that it would be necessary to resort to large-scale subcontracting, it was not until 1940 that the volume of production required reached a point which seemed to justify putting official pressure on the industry to overcome its reluctance.20
But then other difficulties appeared. During 1940 and well into 1941, many small companies which could qualify as subcontractors preferred continuing normal production for the civilian goods industries to gambling on the munitions program. No small part of the more readily convertible firms had valued connections with the automobile industry, and until production of can for the civilian market was cut back, it remained difficult for aircraft manufacturers to find companies willing to take subcontracts. As the munitions share of total production increased during 1941, however, smaller plants began to find themselves at a disadvantage because of difficulty in securing necessary equipment and material in critical supply. A contract with a company working for the government, and especially on some part of the aircraft program, could be helpful in getting supplies, and by the time of Pearl Harbor all parties were perforce inclined to be cooperative. With the coming of hostilities, a drastic curtailment of production for civilian consumption gave the smaller firms no choice. As for the other parries to subcontracts, the overwhelming load with which the aircraft industry had been saddled had largely removed its initial reluctance, and, for good measure, there was now added the strong political pressure for subcontracting which arose from the fear that the war might kill off small business firms as “big business” became bigger. The Air Corps had previously assumed that it lacked the information to guide contractors in their subcontracting. But the Materiel Division as early as December 1940 found it necessary to establish a special organization within its office for the purpose of
locating and making known to large manufacturers the potential capacity for this form of expansion. Working with WPB and the Smaller War Plants Corporation, the AAF throughout the war continued to help bring prime and subordinate contractors together.21
By January 1942 some of the aircraft companies were subcontracting as much as 50 per cent of their work.22 It has been estimated that subcontracting accounted for approximately 30 per cent of the total airframe poundage produced during the war. In the field of aircraft engines the percentage probably ran higher, possibly to as much as 40 per cent. More exact figures are difficult to get, for the practice often involved several tiers of agreements, with one level of subcontractors further subcontracting to a lower level, and so on. For the B-24, Consolidated Vultee depended on as many as 100 subcontractors, some of whom, in turn, resorted to the same device. Subcontractors for the manufacturers producing the B-29 ran into the thousands. In 1943 Boeing was subcontracting more than 40 per cent of its B-17 work, and in 1944 Douglas subcontracted for 40 per cent of its output. One estimate placed the total number of subcontractors in the aircraft industry at more than 162,000.23
Some aircraft manufacturers remained skeptical as to the utility of subcontracting. They found it a singularly complex operation which sometimes placed a load on management as great or greater, it was argued, than that which it was supposed to relieve. The practice undoubtedly added complexity to problems of scheduling, design change, and transportation. One informed survey concluded that subcontracting was much more helpful for large sections and subassemblies of planes than for smaller parts.24 Nevertheless, it seems safe to conclude that the maximum exploitation of the nation’s manufacturing capacity could not have been attained as effectively nor as early by any method other than widespread subcontracting. In this, as with other problems affecting aircraft production, the main burden fell upon organizations outside the AAF. But the AAF, as the principal user of the product, could never be divorced from efforts to solve the varied problems of production. If its basic responsibility was that of the military expert whose function is to advise on the apportionment of productive capacity according to the need for specific weapons, the AAF also, and unavoidably, played a significant part in the development of that capacity.
Special Production Problems
The very novelty of the production techniques employed and the sheer size of the effort resulted in a variety of special problems. Among the more serious of these was the acute shortage of managerial and engineering talent. One study has concluded that the “time required for the peacetime aircraft manufacturers to expand their management personnel ... and to mold their expanded managements into effective operating units was one of the principal factors limiting the speed of the wartime expansion.”25 The aircraft companies in 1940 had only a small nucleus of experienced men around which to build. At the end of 1938 the five leading airframe companies employed an average of 3,500 persons each, at the close of 1943 an average of over 100,000.26 Early anticipation of the need for expanded managerial staffs fell far short of the actual requirement that developed.27 As the automobile industry moved into aircraft production, administrative experience in the latter field took on a new premium. Military organizations drew into their service men for whom a greater need existed at their customary desks – a fact that is attributable not only to the government’s failure to develop better policies for the use of manpower but to the psychological pressure that in time of war makes a man seek military service. The establishment of branch plants, most of them hundreds or thousands of miles from the home office, though offering the advantages of more readily available labor or better security, placed an additional strain on management by forcing it to multiply executive staffs and to resolve the difficulties of new and more complex administrative relationships. By no means least among the new burdens were those imposed by the proliferation of government agencies with which management had to deal on the complex details of contract negotiation or the procurement of tools and materials, not to mention the onus caused by the government’s supervisory rights over a variety of jobs for which it was footing the bill. The demand for engineers so far exceeded the supply that some of them left established firms in order to make huge profits by setting up their own organizations.28
As late as March 1943 Charles E. Wilson, chairman of the Aircraft Production Board, attributed a current lag in aircraft production primarily to unsolved problems of management. On that occasion the AAF disagreed, placing the blame rather on a shortage of materials,29 but at other times AAF leaders emphasized the important role of
managerial inefficiency in the difficulties experienced with particular plants and companies; more than once the AAF insisted upon the replacement of executives who were inefficient and recommended new ones.30 It also rendered concrete assistance at points by releasing experienced executives from military service for more important tasks in production. The blame for these difficulties belongs both to government and to industry, but it would be unfair to close the discussion on a note of disparagement. It seems altogether unlikely that any other industrial group in the United States operated under such relentless strain and tension as was imposed on the aircraft companies and their staffs, managerial and engineering, by the demands of the wartime aircraft program. Their achievement was made a matter of record through one of the great military triumphs of the nation’s history, and in the final balance that achievement outweighs all shortcomings and failures.
During the period from 1940 through 1942 shortages of machine tools also caused trouble. In this area, although the machine-tool industry had always been a small and highly specialized one whose limited capacity could not easily be expanded, the aircraft program, and thus the AAF, fared relatively well. The expansion of aircraft production got a sufficiently early start to give the industry some advantage in the competition for the limited supply of machine tools. As early as 1940 the aircraft industry purchased more machine tools, for the first time in its history, than did the automotive industry, long the largest user of machine tools in the country.31
But there was trouble before the end of 1940. In October of that year the Air Corps requested the Administrator of Export Control to refuse licenses for export of all machine tools that could be used in aircraft manufacturing.32 The urgent needs of the British, and later of the Russians, made it inexpedient to impose a ban on the export of all machine tools, and lend-lease contributed in part to subsequently developing shortages.* The extent to which these shortages were responsible for production delays cannot be expressed in statistical form. At some time or other between 1940 and 1943 almost every major aircraft manufacturer, and more particularly the producers of aircraft engines, ascribed their production problems chiefly to machine-tool shortages. In the spring of 1941 Curtiss-Wright, Ford, Allison,
* In 1942 the U.S. supplied Britain with 47,000 machine tools, of which 18,000 were used in the aircraft industry.
and Continental Motors were all behind in engine deliveries because of lack of machine tools; at other times, Bendix, North American, Douglas, Pratt & Whitney, Packard, Lockheed, Republic, Martin, and others also fell behind for the same reason. The Martin plant at Omaha, which was supposed to be completely equipped by 1 January 1942, had only 50 per cent of its machine tools by that date. In 1942 Vega and Boeing were handicapped in production of B-17’s by shortages of machine tools, and in 1943 late deliveries of tools delayed the Bell plant at Marietta in getting into production of B-29’s, although there were also other more important reasons in the latter case. The effect of these shortages reached down to the lowest tier of subcontractors. Often delivery of engines and airframes was delayed because parts and subassemblies were received late, their production; in turn, being delayed by lack of machine tools or of other parts for which machine tools had not been available in sufficient quantity.33
The AAF served to bring these shortages to the attention of the proper authorities and to make recommendations on desired priorities. It also threw its influence into an effort to secure more effective policies and machinery for control of the distribution of machine tools. After Pearl Harbor there was established a government pool of the commonly used tools for assignment, by lease or purchase, to the manufacturers,34 and this move proved very helpful. By the end of 1942 the aircraft industry was largely tooled up.
As the machine-tool deficiency was being overcome, it appeared that shortages of materials, and especially of aluminum, would succeed it as one of the major sources of difficulty. Although prewar plans for mobilization had included surveys of the existing and potential capacity of the aluminum industry, the Air Corps in 1940 lacked the data necessary for an accurate estimate of its future needs. Plans drafted during that summer depended chiefly upon figures supplied by the Aluminum Company of America, at that time the only producer of aluminum in the United States,* and estimates made in connection with the President’s program for aircraft production proved subsequently to have been decidedly low.35 Not only were the assumptions which shaped initial plans for expansion of the industry’s capacity wrong, but the successive and drastic upward revision of goals for aircraft production tended to open new gaps between the demand
* The Reynolds Metals Company produced a substantial quantity of aluminum during the war, and Kaiser and Bohn were getting into production at the end of the war.
and the supply of aluminum. Even though the production of primary aluminum might be up to estimated requirements, the supply might not be sufficient in the shapes and forms – forgings, extrusions, and high-strength sheet – needed for the manufacture of planes. Aluminum shortages affected the production of several aircraft companies – among them North American, Martin, and Northrop – from the very outset of their expansion, and the Air Corps early in 1941 attributed delays in delivery of the B-17E, the B-24D, and the P-40D to shortages of aluminum alloy tubes and forgings.36 Further trouble arose from the lack of adequate controls and from the consequent tendency of some manufacturers to hoard surpluses badly needed by other companies. Shipments of large stocks to Great Britain and to Russia also helped to keep the situation in the United States a tight one.
Although the government had sponsored a major expansion of aluminum capacity during 1941, including provision for fabricating facilities, and had arranged for large purchases from Canadian sources, the coming of the war and the greatly increased aircraft program announced by the President in January 1942 automatically rendered obsolete all existing plans. The President, even before the public announcement of the new objectives, had demanded attention to the need for expansion of aluminum production and for a substantial reduction of its use in the shipbuilding program. Late in January, Lovett felt impelled to protest vigorously the continued use of aluminum by the Navy for mobile kitchens, ship galleys, soda fountains, lockers, and similar items. If the established aircraft goals were to be met, he warned Hopkins, more than 80 per cent of aluminum production would be required and a strong system of priorities would have to be fixed in accordance with this fact.37 But not until the second quarter of 1943, when the Controlled Materials Plan was adopted,* was the AAF satisfied with the provision for distribution of available stocks.
Meantime, the AAF became a spokesman for the aircraft manufacturers – who consistently attributed to shortages of materials, particularly aluminum, their failures to deliver the goods on time – and pressed on other government agencies the need for assistance. Lovett in, formed Hopkins in March 1942 that Ford could double its daily production of 2,000-horsepower motors if only it could get the necessary aluminum.38 The seriousness with which the AAF itself viewed the
* This plan, by controlling the allocation of steel, copper, and aluminum, was successful in producing a smoother flow of raw materials throughout the munitions industry.
problem is indicated by its attempts to develop combat and transport aircraft models built of other materials (chiefly steel and wood), experiments that proved disappointing.* WPB officials tended to counter the complaints made by the manufacturers with charges of improper and untimely ordering by the aircraft companies, their failure to maintain proper controls of inventory, and continued hoarding. In short, the failure was one of management and not of supply. When Charles E. Wilson, as chairman of the Aircraft Production Board, made this view a specific charge in a communication to the President of March 1943, the AAF sharply disagreed, asserting that delays in aircraft production must be attributed chiefly to shortages in the supply of necessary materials.39 The disagreement reflected something of the pressure under which all parties worked at this critical point in the productive effort, and of the circumstances which naturally made of the AAF an advocate of the manufacturers’ point of view before those authorities who exercised ultimate control over the distribution of critically needed materials.
After the summer of 1943 the aluminum shortage effected a real limitation on aircraft production only in isolated instances. Not only did adoption of the Controlled Materials Plan result in a smoother and more equitable distribution of available stocks, but technical advances in the fabrication of aluminum helped eliminate the particular shortages of which there had been the most complaint. By the end of 1943 the supply and production of aluminum was so well in hand that the construction of three new extrusion plants was canceled.40 During 1944, as the munitions program passed its peak, the manufacture of aluminum was curtailed for fear of overproduction, which threatened to reach large proportions. The failure to end the European war in 1944. and the sudden panic engendered by the German Ardennes offensive in December of that year caused the armed services to raise their munitions goals once again. The new demand for aluminum was also swelled by an earlier failure accurately to estimate the requirement for B-29 production. Requirements for sheet aluminum in the first quarter of 1945 jumped so per cent over the previous quarter.41 In January 1945 the shortage of aluminum sheet and extrusions be-came severe enough to persuade the AAF in February to release 1,000 soldiers on 90-day emergency furloughs for work in the aluminum plant at Alcoa, Tennessee. Production increased during the first quarter, and during the second quarter Germany’s collapse gave assurance
* Among them were the XP-57, P-66, YC-61, YC-76, and UC-78.
that stated requirements for most types of aluminum would not have to be met. A shortage of certain forms, particularly ingots, persisted, but the Japanese surrender soon brought upon the industry a surplus of both capacity and stocks.42
As the more pressing problems relating to shortages of machine tools and materials approached solution in the latter half of 1943, they were succeeded by a growing concern over a threatened labor shortage. It is debatable whether an over-all shortage of manpower existed in the aircraft industry at any time during the war, but the fear of it did exist after 1943 and from first to last a variety of difficulties involving the labor force on which the aircraft industry depended repeatedly required AAF attention.
The rapid expansion of the aircraft industry after 1939 produced a twenty fold increase in the labor force between January 1940 and December 1943, from perhaps 100,000 to almost 2,100,000.* Prime contractors in airframe, engine, and propeller plants employed more than 1,300,000 persons in December 1943, compared with something less than 80,000 in January 1940. After January 1944 there was a steady decline in employment to approximately 1,230,000 in July 1945, and a drastic cutback to 500,000 in August, the first postwar month.43
Because the rapid expansion of the aircraft industry was accompanied by a prompt shift to production techniques permitting the employment of unskilled or semiskilled workers, the industry suffered no serious problem in recruiting a labor force large enough for its needs. And since its expansion predated any comparable increase ‘of the military forces, the inroads made on its labor force by calls to military service were less serious than with industries whose expansion came at a later stage in the war. As enlistment and conscription cut down the number of younger men available, it was possible to replace them by use of resources theretofore not fully exploited – notably women and Negroes. The location of so much of the new plant in interior areas remote from the more competitive labor markets provided another advantage, its benefit coming for the most part at the very time when a pinch in the labor supply might have been expected.† Anticipated shortages after 1943 proved to be nowhere near
* Including vendors and subcontractors.
† In June 1942 only 6 per cent of total employment in plants operated by prime contractors was located outside the two coastal areas. Two years later almost half of the total number of employees were working in plants situated in the interior of the country.
so serious as had been feared, partly because estimates of the need were considerably in excess of that which actually developed.44 The great difficulty lay in the supply of skilled labor, which not even new techniques of production could do without and which, indeed, became all the more indispensable for supervision of the greatly increased force of unskilled labor.
As the demands of selective service began to drain the aircraft plants of an increasing number of trained technicians and supervisors, the AAF responded to bitter protests from the manufacturers by interceding with the Selective Service System to limit the drafting of key technicians, and the AAF was able to secure deferments for large numbers of such young men. On at least one occasion, in 1943, the AAF itself released men from active military service, transferred them to the Enlisted Reserve Corps, and placed them in Wright’s Wood-Ridge engine plant for a period of six months, later extended to twelve.45 The need to defer specially qualified personnel was all the greater because of the high rate of turnover among other aircraft employees. Although the turnover rate was lower than in most other munitions industries, aircraft manufacturers in 1941 had to hire 1,900 workers in order to increase employment by 1,000, and in 1942 they had to hire 2,100 workers to obtain an increase of 1,000. For the six-month period of December 1944 through May 1945, even though there was a reduction by 89,400 in the labor force needed by prime airplane contractors, these companies had to hire 200,000 workers. Under such circumstances, the importance of a trained nucleus of key technicians and supervisors becomes obvious, and the effort to secure military deferments for these men quite understandable.46
There were other problems which, taken together, were hardly less serious. Absentee rates of 6 to 8 per cent in 1943–44 had such serious consequences that the AAF conducted surveys of absenteeism for the purpose of helping the manufacturers reduce the excessive rate. The AAF also contributed materially to the settlement of labor disputes, frequently before they erupted into strikes. Where settlements could not be obtained and stoppage of production at key plants was threatened or had occurred, the AAF became the responsible agent for operation of such plants when taken over by the government, a responsibility which the AAF was generally reluctant to assume. In attempts to support the morale of aircraft workers, the AAF gave attention to provisions for good shop conditions in negotiating
contracts for plant expansion. It also tried to improve the worker’s morale by stressing the vital significance of his task.47
The final measure of the utilization of manpower was in its productivity, and here, in spite of the declining quality of the worker, there was an impressive growth. The average accepted airframe weight per employee per month increased from 21 pounds in January 1941 to 49 pounds in March 1943 and to 96 pounds in May 1944. During 1941 part of the increase was the result of longer hours of work, but after-wards the figures represent an actual increase in hourly output. In 1944 the labor cost per pound of airframe was only about a third of the cost early in 1941, although earnings per hour had increased more than 50 per cent.48
One final difficulty, failure to provide adequately for spare parts, deserves special attention, and for this serious failure the AAF itself must shoulder the primary responsibility. Before 1939 it had been established practice to procure, concurrently with new planes, spare parts at a ratio ranging up to 25 per cent of the money value of the total number of planes. This figure, though representing the estimate of need under peacetime conditions, was larger than it might other-wise have been because limited appropriations for the Air Corps left it no choice but to keep its planes in active service over an extended period of time. During the war years, from 1 July 1940 to 31 August 1945, spare-parts production, measured by weight, equaled 14 per cent of airframe production. The number of engine and propeller spares came to 65 per cent of the total initially installed on AAF planes.49
In 1939 Arnold had gambled on the prospect that additional funds for the purchase of spare parts would come through promptly enough to permit him to use all currently available funds for the purchase of complete aircraft. White House pressure to procure the maximum number of planes was strong, so strong as perhaps to justify an assumption that once the government was committed to a program on the scale proposed, it would also readily provide the money for indispensable spares. Unfortunately, however, the necessary funds did not become available for more than a year, and it took much longer still to overcome the disruptive effect of this time lag. In May 1941 the 10th Pursuit Group reported an average of 30 per cent of its planes out of commission for lack of spare parts, a condition probably typical of most combat groups at that time.50 By the summer of 1941 the
shortage of spares had become severe enough to force the Air Corps to use about one-fifth of its new plane deliveries to provide parts; thus “cannibalizing” some planes to keep others in operation received early official sanction. The shortage was felt more acutely by AAF units because first claim on available spares went to RAF units using U.S. planes in combat. Even so, the RAF in the Middle East encountered serious difficulties in the operation of its American-built planes because of an insufficient supply of spares. Reporting this condition to Arnold late in August 1941, AM Arthur T. Harris, then head of the RAF delegation in Washington, sympathetically recalled the RAF’s own unhappy experience with the same problem that plagued Arnold. It, too, had yielded in 1938 to political pressure for the purchase of complete planes, and was still struggling to overcome the acute shortage of spare parts which resulted. Harris urged that the AAF give the most careful attention to the production of parts.51 The question already had become the subject of anxious discussion in War Department circles, and on 2 September Arnold directed that spare parts be procured at the same time as complete aircraft in all current and future contracts. Spares for planes already in service were also to be procured as promptly as possible without disrupting the current production of aircraft.52 Even at this late hour the pressure for aircraft production was apparently such as to argue against resort to a drastic solution.
That pressure had its effect also on the attitude of the manufacturers. Anxious to gain the advantage of a good record on the delivery of complete aircraft, they at times kept to schedule, or at any rate close to it, by neglecting the production of spares. Subsequent experience suggests, too, that the Air Corps, though alert enough to the need, tended before Pearl Harbor to underestimate the requirement and to make insufficient provision for spare parts.53 After Pearl Harbor, the number of planes grounded for lack of spare parts reached an alarming rate. From theaters of combat, where damaged and even fully serviceable planes were cannibalized to provide spare parts and engines, came ever more insistent demands for help as combat damage and the backlog of unrepaired aircraft grew apace. During 1942 the demand became at times so great that engines were actually removed from aircraft in the United States for shipment overseas.
The AAF, in turn, put pressure on the manufacturers. Besides its policy of demanding delivery of spare parts concurrently with the
aircraft, the AAF now asked for an additional 10 per cent payment on the backlog of undelivered parts. When some manufacturers showed reluctance to accept these terms, the AAF insisted that all arrears be cleared up by the end of 1942. At midyear improvement was apparent, but the shortage of engine parts had become so critical as to lead to an order for delivery of these parts without regard to the effect upon the production of complete engines during the months of June and July. And more than once during that year the AAF indicated its willingness to accept delays in the production of finished aircraft in order to get spare parts which were in particularly critical supply.54 Late in 1942 the AAF undertook to establish a policy of procuring spare engines at a rate of son per cent replacement for all combat and transport aircraft scheduled for use overseas, but the Joint Aircraft Committee, which recognized that this goal could be achieved only at too great a cost to the production of new aircraft, set the figure at 40 per cent.55 The alternative left to the AAF was to make a more careful allocation and distribution of the engines which would be made available to it.
By early 1943 the Joint Aircraft Committee was urging strong measures to reduce the production of spare parts, and particularly of large airframe components which consumed such quantities of relatively scarce aluminum extrusions as to threaten delay in the accomplishment of over-all programs. But the AAF still occasionally found it necessary during 1943 to sacrifice complete plane and engine production to the manufacture of spare parts; in August, for example, the Materiel Command was ordered to curtail production of up to 200 B-24’s in order to get spares for the planes already in service. AAF policy, as stated in October 1943, gave the same priority to planes and spare parts.56 Because of frequent changes in models and variations in their rates of attrition, the determination of requirements for spares remained a difficulty even after war production had reached its peak. Shortages and surpluses occurred during 1944–45 in spite of frequent efforts to improve the whole procedure for procuring and distributing spare parts.57
The major share of the responsibility clearly falls on the AAF. Though the manufacturers, sometimes for reasons beyond their control, often failed to meet the AAF’s orders for spare parts, the latter had not developed an effective system for calculating requirements and scheduling production in time to prevent the critical shortages
which marked the early years of combat operations. Not until 1943 would the time initially lost in the provision of parts be fully recovered.
The Measure of the Production Achievement
By 7 December 1941 the United States had become the foremost producer of military aircraft in the world. In less than two years the American aircraft industry had overtaken the other powers of the world in rate of production, despite the head start they all enjoyed and despite the export to later allies of production equipment and materials which conceivably could have been used for a still greater increase of American aircraft production. The achievement after 7 December 1941 was even more impressive. From an annual production rate of about 25,000 planes as of November 1941, American production reached a peak rate of almost 110,000 planes as of March 1944. The 9,113 planes turned out in that month came close to equaling the combined production for the same period of the other four major powers involved in the war. The comparative figures for the entire war are as follows:58
| Year | Japan | Germany | Great Britain | United States |
| 1939 | 4,467 | 8,295 | 7,940 | 2,141 |
| 1940 | 4,768 | 10,826 | 15,049 | 6,086 |
| 1941 | 5,088 | 11,776 | 20,094 | 19,433 |
| 1942 | 8,861 | 15,556 | 23,672 | 47,836 |
| 1943 | 16,693 | 25,527 | 26,263 | 85,898 |
| 1944 | 28,180 | 39,807 | 26,461 | 96,318 |
| 1945 | 8,263* | – | 12,070† | 46,001* |
* Eight months only for U.S. and 7½ months for Japan
† First three quarters only.
Official statistics of Russian aircraft production are not available. In a speech early in 1946 Stalin spoke of Russian production as having reached a rate of 40,000 planes per year during 1944.
If the more accurate index of airframe weight be used, U.S. production in all probability greatly exceeded the combined total for the rest of the world in 1944. The American industry produced 1,101,116,000 pounds, including spares; the British 208,520,000 pounds; and the German 174,939,000 pounds. Japanese production may be reliably estimated at a little better than 100,000,000 pounds. If one accepts a maximum figure of 200,000,000 pounds for Russia, based on Stalin’s figure of 40,000 planes and on the assumption that these were the lighter type commonly employed by the Russians in tactical support
of their ground forces, the total for the four powers is under 700,000,000 pounds or less than two-thirds of the American production.59
These figures reflect significant differences in the aircraft programs of the several powers. In the United States after March 1944, although production declined as requirements were cut back, the average weight per unit continued to increase as a result of the emphasis placed upon the production of large planes for strategic bombardment or for ATC’s world-wide system of air transport. Only the British figures offer a parallel with the steady rise in average unit airframe weight which characterized American production.* In Germany and Japan, neither of which had at any time gone in for heavy bomber production on the scale adopted by the British and the Americans,† there came with the receding tides of their military fortunes a growing emphasis on the smaller defensive type of plane. Single-engine fighters constituted 65 per cent of the total number of planes produced by Germany in 1944, a figure that compares with 24.2 per cent in 1941 and offers eloquent tribute to the increasing effectiveness of RAF and AAF bomber operations. Similarly, fighters accounted for almost 50 per cent of Japanese production in 1944, or two and a half times the 21 per cent of 1941. Although German and Japanese production increased significantly during 1943 and 1944, the increase in airframe weight was not in proportion to the increase in numbers. German aircraft production increased by about 65 per cent from 1942 to 1943 and just under 60 per cent from 1943 to 1944. But airframe weight for the same years increased only 48 per cent and 23 per cent. The average unit weight of German airframes decreased from 1941 to 1944, falling from some 7,000 pounds to little more than 4,000 pounds. Germany’s total airframe production of almost 175 million pounds in 1944 was greatly exceeded by the total production of only four U.S. plants – 92 million pounds by Ford at Willow Run, 70 million pounds by Boeing at Seattle, 67 million pounds by Consolidated Vultee at San Diego, and 55 million pounds by Douglas at Long Beach.60
* From the beginning of 1941 to the end of 1944, the average unit weight of American planes, excluding spares, rose from less than 3,500 to almost 11,000 pounds. Including spares, the figures are roughly 4,000 and 12,000. In Britain, which placed a comparable emphasis on bomber production but not transports, the approximate average in 1941 was 4,300 pounds, and in 1944, 8,000 pounds.
† Four-engine bombers never constituted more than 1.9 per cent of German production in any one year. In 1944 they comprised 17 per cent of American production.
Of the grand total of 299,293* planes produced in the United States between 1 July 1940 and 30 August 1945, the AAF had cognizance of 230,175, the Navy of 69,118.61 These totals included the many aircraft accepted by the two services for transfer to our allies under lend-lease, of which the greater proportion were of Army type. The AAF figure includes approximately 43,000 lend-lease planes of which Great Britain and Russia received the lion’s share – 25,870 and 14,612 respectively.62 Speaking in terms of numbers, planes of AAF cognizance represented roughly 70 per cent of total production, but because of the greater weight of Army types, the AAF’s share comprised 82 per cent of the total airframe weight produced. In view of the fact that few heavy bombers were transferred under lend-lease, the percentage of production actually going to the use of the AAF was probably larger still. Of the 802,161 engines accepted during the period, the AAF received 653,647 (81 per cent) and the Navy 148,514.63
The total number of military and special purpose aircraft, by type, accepted by the military services in the period extending from July 1940 through August 1945 is shown in the following table:64
| Type | 1940 | 1941 | 1942 | 1943 | 1944 | 1945 | Total |
| Bomber | 623 | 4,115 | 12,627 | 29,355 | 35,003 | 16,087 | 97,810 |
| Fighter | 1,162 | 4,416 | 10,769 | 23,988 | 38,873 | 20,742 | 99,950 |
| Reconnaissance | 63 | 727 | 1,468 | 734 | 259 | 667 | 3,918 |
| Transport | 164 | 532 | 1,984 | 7,012 | 9,834 | 4,403 | 23,929 |
| Trainer | 1,794 | 9,373 | 17,631 | 19,939 | 7,577 | 1,309 | 57,623 |
| Communications | 1 | 270 | 3,174 | 4,377 | 3,691 | 2,130 | 13,643 |
| Special Purpose | 0 | 0 | 183 | 493 | 108 | 663 | 2,420 |
| 3,807 | 19,433 | 47,836 | 85,898 | 96,318 | 46,001 | 299,293 |
The growing preponderance of combat planes, especially bombers and fighters, over all others is even more clearly depicted by the accompanying table (p. 353) for the same period of acceptances listed in terms of airframe weight by thousands of pounds, including spare parts.65 Bombers and fighters accounted for approximately 83 per cent of the total airframe weight produced during 1940–45, as compared with less than 67 per cent of the total number of planes. Bombers alone comprised more than 61 per cent of total airframe
* This figure includes 5,254 planes produced for the United States in Canadian plants and 2,420 special purpose (target) aircraft. In addition, the United States produced 15,793 gliders plus civilian planes as follows: 6,785 in 1940, 6,844 in 1941, and 985 in 1942.
weight although they constituted only 32 per cent of aircraft production by number. The importance of the bomber in the aircraft production scheme is further underlined by the fact that heavy bombers (B-29, B-24, B-17), which comprised less than 12 per cent of aircraft production by number, required more than 35 per cent of total airframe weight.66 By contrast, training planes, which numbered 20 per cent of total production, made up only 5 per cent of the airframe weight produced.
| Type | 1940 | 1941 | 1942 | 1943 | 1944 | 1945 | Total |
| Bomber | 5,091 | 45,607 | 182,672 | 484,068 | 682,313 | 348,010 | 1,747,761 |
| Fighter | 3,793 | 18,732 | 58,146 | 145,593 | 258,377 | 139,048 | 623,689 |
| Reconnaissance | 122 | 2,068 | 5,737 | 4,678 | 1,380 | 3,391 | 17,376 |
| Transport | 1,205 | 3,780 | 19,969 | 63,313 | 129,709 | 82,344 | 300,320 |
| Trainer | 3,389 | 19,917 | 45,953 | 56,793 | 24,458 | 4,638 | 155,178 |
| Communications | 2 | 378 | 2,192 | 3,893 | 3,464 | 2,280 | 12,209 |
| Special Purpose | 0 | 0 | 119 | 449 | 1,385 | 612 | 2,565 |
| 13,602 | 90,482 | 314,788 | 758,787 | 1,101,116 | 580,323 | 2,859,098 |
Acceptances of aircraft engines for the period covered by preceding tables were:67
| 1940 | 15,513 | 1943 | 227,116 |
| 1941 | 58,181 | 1944 | 256,912 |
| 1942 | 138,089 | 1945 | 106,350 |
| Total | 802,161 |
Combat engines (those with a displacement of more than 1,340 cubic inches) numbered 633,082, trainer engines (under 1,340 cubic inches), 168,178, and turbojet engines only 901. Production of engines for combat aircraft did not exceed those for trainers until 1942. In 1945 production of heavy combat engines, those over 1,600 horsepower, exceeded all others, reflecting the emphasis on bombers and more powerful fighters. After lagging behind in 1940–41 and constituting a bottleneck in the assembly of complete aircraft, the production of propellers between 1 July 1940 and 31 August 1945 rose to the grand total of 807,424. About 80 per cent of the propellers were hydraulic, and most of the remainder were electric.68
The eighteen combat models upon which the AAF and the Navy chiefly depended during the war accounted for more than 86 per cent of the 201,678 combat planes produced between July 1940 and August 1945. Acceptances by model were as shown in the table at the top of page 354.69
| AAF | Navy | ||
| B-29 | 3,760 | SB2C | 6,130 |
| B-24 | 18,188 | SBD | 5,320 |
| B-17 | 12,677 | TBM-TBF | 9,812 |
| B-25 | 9,815 | F4U | 11,236 |
| B-26 | 5,157 | FM, F4F | 7,898 |
| A-20 | 7,230 | F6F | 12,210 |
| A-26 | 2,446 | ||
| P-38 | 9,535 | ||
| P-51 | 14,490 | ||
| P-47 | 15,579 | ||
| P-40 | 13,700 | ||
| P-39 | 9,585 | ||
| TOTAL | 122,162 | TOTAL | 52,606 |
Production for each of the three chief transport models was:
| C-54 | 1,089 |
| C-46 | 3,144 |
| C-47 | 10,245 |
The grand total of 23,929 transports represented less than 8 per cent of total aircraft production, but their airframe weight of 300,320,000 pounds was 10.5 per cent of the total.70
The established manufacturers of 1940 continued to dominate the industry throughout the war. The eleven leading companies delivered 229,554 planes (more than 70 per cent of all of the planes accepted between 1 July 1940 and 31 August 1945), with acceptances for each of them standing finally at the following figures:71
| North American | 41,188 |
| Consolidated Vultee | 30,903 |
| Douglas | 30,696 |
| Curtiss | 26,154 |
| Lockheed | 18,926 |
| Boeing | 18,381 |
| Grumman | 17,428 |
| Republic | 15,603 |
| Bell | 13,575 |
| Martin | 8,810 |
| Chance Vought | 7,890 |
Three other firms – Ford, Goodyear, and the Eastern Aircraft Division of General Motors – produced an additional 24,180 planes among them, distributed as follows: Eastern Aircraft (13,449), Ford (6,791), and Goodyear (3,940).72 Acceptances by airframe weight, listed in thousands of pounds with spares excluded and for the calendar years 1940 through 1944,.73 change the order indicated in the preceding table, as shown in the table on page 355. Four companies, it will be noted, produced more than 50 per cent of the total airframe weight during 1940–44. North American, first in number of planes produced,
was fourth in airframe weight, a large proportion of its output having been trainers and fighters. The other three – Douglas, Consolidated Vultee, and Boeing – supplied the bulk of bombers and transports, with Douglas carrying the main load with the latter type. The greatest quantity of airframe poundage produced at one plant in any one year was at Ford’s Willow Run factory in 1944–92,568,000 pounds. For the five-year period 1940–44, the Consolidated Vultee plant at San Diego produced 180,702,000 pounds of airframe weight, or 9.1 per cent of the total amount produced in the country.
| Company | Total | Per Cent of 5-Year Grand Total |
| Douglas | 306,573 | 15.3 |
| Consolidated Vultee | 291,073 | 14.6 |
| Boeing | 226,477 | 11.3 |
| North American | 210,913 | 10.5 |
| Lockheed | 189,118 | 9.0 |
| Curtiss | 136,091 | 6.9 |
| Martin | 126,970 | 6.3 |
| Ford | 123,076 | 6.2 |
| Republic | 75,893 | 3.9 |
| Grumman | 73,767 | 3.7 |
| Bell | 53,037 | 2.7 |
| Eastern | 47,869 | 2.4 |
| Chance Vought | 28,952 | 1.4 |
| Goodyear | 13,668 | 0.7 |
| All other plants | 101,136 | 5.1 |
| Grand total-all plants | 1,995,613 | 100.0 |
Pratt & Whitney and Wright maintained a traditional leadership in the field of engine production. As the table at the top of page 356 indicates, it was possible to meet demands for engines only by the aid of licensees drawn from the automotive firms.74 These figures are particularly significant for the light they throw on the distinctive policies of the two leading producers. It will be recalled that Wright preferred to expand through the establishment of branch plants operated under its own control but Pratt & Whitney depended heavily upon licenses to other firms. It would appear that the latter’s policy proved to be the more effective means of increasing production. Wright produced more engine horsepower from 1938 through 1941, but Pratt & Whitney and its licensees out-produced Wright by a substantial margin for the remainder of the war.75
In the propeller industry Curtiss-Wright and Hamilton Standard
Engine Acceptance by Companies*
(1 July 1940–31 August 1945)
| Wright | 136,494 | |
| Wright and Licensees | Studebaker | 63,789 |
| Dodge | 18,349 | |
| TOTAL | 218,632 | |
| Pratt & Whitney | 130,117 | |
| Buick | 74,198 | |
| Chevrolet | 60,766 | |
| Pratt & Whitney and Licensees | Ford | 57,178 |
| Packard | 54,714 | |
| Nash-Kelvinator | 17,012 | |
| TOTAL | 393,985 | |
| Allison | 69,618 | |
| Jacobs | 32,119 | |
| Independents | Continental Motors | 28,824 |
| Lycoming | 24,871 | |
| Ranger | 14,266 | |
| TOTAL | 169,698 |
* A number of smaller companies produced an additional 19,846 engines for a grand total of 802,161.
continued as the dominant manufacturers, although Nash-Kelvinator, one of Hamilton Standard’s licensees, surpassed Curtiss-Wright’s output for the period, as the following table of acceptances of hydraulic and electric propellers for the period 1 July 1940–31 August 1945 indicates:76
| Hamilton Standard | 233,021 |
| Nash-Kelvinator | 158,134 |
| Curtiss-Wright | 144,563 |
| Frigidaire | 76,626 |
| Remington Rand | 62,354 |
| Aero products | 20,773 |
Most of the other manufacturers were also licensees of Hamilton Standard. As with engines, Curtiss-Wright preferred to expand its own capacity rather than license outside companies.
While over-all figures on production are both impressive and significant, they fail in themselves to lend proper emphasis to what was from the military point of view much more important – the accelerated
rate of production. It was not merely that the planes were produced in the quantities and types required, but that they were produced on the time schedules demanded by strategic plans. The following table of elapsed time between the initiation of design on twelve major combat planes and acceptance of the 500th article, a point at which quantity production must be presumed to be well under way, offers interesting evidence on the acceleration of production during the war years:77
| Start of Design | Prototype First Flown | First Production Article | 500th Acceptance | Approximate No. of Years | |
| B-17 | Aug. 1934 | 1935 | 1939 | Apr. 1942 | 7¾ |
| P-39 | June 1936 | Apr. 1939 | Sept. 1940 | Oct. 1941 | 5¼ |
| A-20* | 1937 | 1938 | - | May 1941 | 4 |
| P-40 | Mar. 1937 | Oct. 1938 | May 1940 | Nov. 1940 | 3½ |
| P-38 | June 1937 | 1938 | Sept. 1940 | Apr. 1942 | 4¾ |
| B-25 | Feb. 1938 | Feb. 1941 | Feb. 1941 | Apr. 1942 | 4¼ |
| B-24 | Sept. 1938 | Dec. 1939 | June 1941 | June 1942 | 3¾ |
| B-26 | June 1939 | Nov. 1940 | Feb. 1941 | July 1942 | 3 |
| P-51 | May 1940 | 1940 | Aug. 1941 | May 1942 | 2 |
| B-29 | June 1940 | Sept. 1942 | July 1943 | July 1944 | 4 |
| P-47 | July 1940 | May 1941 | Dec. 1941 | Dec. 1942 | 2½ |
| A-26 | Jan. 1941 | July 1942 | Sept. 1943 | Nov. 1944 | 3¾ |
* The A-20 was originally the Douglas DB-7, and the first production article probably flew in 1938 or early 1939. It is likely that the 500th acceptance occurred before May 1941.
The average elapsed time is somewhat distorted by the 71 years attributed to the B-17, for this was a special case in which production was unduly delayed for other than technical reasons.* Not until June 1940 was a production contract let for more than 25 B-17’s. Leaving the B-17 aside, the elapsed time for the six planes initiated prior to 1939 averages approximately 44 years from the start of design to the acceptance of the 500th plane; for the five planes designed after 1938 the rough figure is 3 years, or a gain of approximately 15 months. The difference reflects the influence of a multitude of complexly interrelated factors, but they may be summed up briefly and simply in this way: within the Air Corps and in the industry there came a shift from the more leisurely procedures of peacetime to the pace demanded by a state of emergency, and men acted with new assurance as to what would be expected of them and what could be attempted.
* See above, pp. 203-6.
If one speaks in terms of the percentage of increase of production, the critical years were 1941 and 1942. Tabulation of annual acceptances of military aircraft from 1940 through 1944 shows the following results:78
| Total Number | Per Cent of 5-Year Total | Per Cent of Increase over Preceding Year | |
| 1940 | 6,028 | 2.3 | |
| 1941 | 19,433 | 7.6 | 222 |
| 1942 | 47,836 | 18.7 | 146 |
| 1943 | 85,898 | 33.6 | 80 |
| 1944 | 96,318 | 37.7 | 12 |
| Grand total | 255,513 | 99.9* |
* The remaining .1 per cent was distributed over the five-year period.
So much of the earliest production went into provision for the needs of the training program that one naturally turns to the record on combat planes. Acceptances restricted to that category still emphasize the importance of 1941 in the development of productive capacity, but a heavier emphasis falls upon the 1942 and 1943 increases than in the preceding table:79
| Total Number | Per Cent of 5-Year Total | Per Cent of Increase over Preceding Year | |
| 1940 | 2,986 | 1.8 | |
| 1941 | 9,258 | 5.6 | 210 |
| 1942 | 24,864 | 15.0 | 169 |
| 1943 | 54,077 | 32.7 | 117 |
| 1944 | 74,135 | 44.8 | 37 |
| Grand total | 165,320 | 99.9* |
* The remaining .1 per cent was distributed over the five-year period.
A similar result is secured by tabulating acceptances in terms of airframe weight, spare parts included:80
| Total Poundage | Per Cent of 5-Year Total | Per Cent of Increase over Preceding Year | |
| 1940 | 24,600,000 | 1.1 | |
| 1941 | 90,482,000 | 3.9 | 263 |
| 1942 | 314,788,000 | 13.8 | 247 |
| 1943 | 758,787,000 | 33.1 | 134 |
| 1944 | 1,101,116,000 | 48.1 | 45 |
| Grand total | 2,289,773,000 | 100.0 |
And if the heavy bomber program (which to the AAF at least out-ranked all other programs in importance) be the test, 1942 becomes
decidedly the most significant single year in the production record. The following table measures percentages of increase both by number and by the airframe weight of the heavy bombers accepted:81
| Number | Per Cent of 5-Year Total | Per Cent Increase over Preceding Yr. | Airframe (Thousands of Pounds) | Per Cent of 5-Year Total | Per Cent Increase over Preceding Yr. | |
| 1940 | 61 | .2 | 2,000 | .2 | ||
| 1941 | 313 | 1.1 | 413 | 6,942 | .9 | 247 |
| 1942 | 2,576 | 9.0 | 723 | 66,774 | 8.6 | 862 |
| 1943 | 9,485 | 33.3 | 268 | 257,336 | 33.0 | 285 |
| 1944 | 16,045 | 56.3 | 69 | 446,060 | 57.2 | 73 |
| Grand total | 28,480 | 99.9 | 779,112 | 99.9 |
But percentages tell less than the actual figures on production listed in the tables above, which make it clear enough that it was in 1942 that the aircraft industry really got into production and that by the close of 1943 the problems of production had been so far whipped as to assure the overwhelming supremacy enjoyed by U.S. air arms in 1944 and 1945. That supremacy represented more than an industrial victory won on the home front; it bespoke the cumulative effects of many hard-won tactical victories on the battle fronts and the achievements of a training program no less impressive in its scale than was the production program, but under the conditions of modern war it is production that makes all else possible, and more especially production in time to count. By December 1941, the month of Pearl Harbor, the production of military aircraft had reached an annual rate of 29,000, which was impressive enough for a period when the problem had been not so much actual production as the creation of a production potential. By December 1942, when the Allied powers had only recently begun to seize the military initiative, U.S. plants were turning out planes at a rate of 65,000 per year. By December 1943, six months ahead of the invasion of Normandy, production had reached a rate of 105,000 planes per year. During the twelve months extending from September 1943 through August 1944 acceptances of military aircraft by the military services totaled 101,409 planes, the overwhelming percentage of them being combat models.82
The cost of the aircraft program for World War II has been estimated at approximately $45 billion. In terms of the most important
combat and transport aircraft models, the average unit cost* was as follows:83
| Model | 1939–41 | 1942 | 1943 | 1944 | 1945 |
| B-17 | $301,221 | 258,949 | - | 204,370 | 187,742 |
| B-24 | 379,162 | 304,391 | - | - | 215,516 |
| B-25 | 180,031 | 153,396 | 151,894 | 142,194 | 116,752 |
| B-26 | 261,062 | 239,655 | 212,932 | 192,427 | - |
| B-29 | - | - | 893,730 | 605,360 | 509,465 |
| A-20 | 136,813 | 124,253 | 110,324 | 100,800 | - |
| A-26 | 224,498 | - | 254,624 | 192,457 | 175,892 |
| P-38 | 134,284 | 120,407 | 105,567 | 97,147 | - |
| P-39 | 779o9 | 69,534 | - | 50,666 | - |
| P-40 | 60,562 | 59,444 | 49,449 | 44,892 | - |
| P-47 | 113,246 | 105,594 | 104,258 | 85,578 | 83,001 |
| P-51 | - | 58,698 | 58,824 | 51,572 | 50,985 |
| C-46 | 341,831 | 314,700 | 259,268 | 233,377 | 221,550 |
| C-47 | 128,761 | 109,696 | 92,417 | 88,574 | 85,035 |
| C-54 | 516,553 | 370,492 | 400,831 | 285,113 | 259,816 |
The great contrast between the cost of combat and noncombat aircraft† is revealed in the following table of costs of training and communications aircraft:84
| Model | 1939–41 | 1942 | 1943 | 1944 | 1945 |
| PT-13 series | $10,002 | 9,896 | - | - | - |
| PT-19 series | 9,710 | 12,911 | 11,000 | 15,052 | - |
| BT-13 series | 25,035 | 23,068 | - | - | - |
| AT-6 | 29,423 | 25,672 | - | 22,952 | - |
| AT-7 series | 76,827 | 85,688 | 68,441 | - | - |
| L-4 | - | 2,432 | 2,437 | 2,620 | 2,701 |
| L-5 | - | 10,165 | - | 9,704 | 8,323 |
The steady decrease in the cost of almost every type of plane was, of course, the result of volume production, and the decrease undoubtedly would have been greater had there been no changes in the various models between 1940 and 1945. But great changes did occur, and almost every model became larger and more complex as more armor, armament, communications equipment, and fuel tanks were installed.
* The unit cost for the first year usually included the experimental and test models which were, of course, far more costly than the production models which followed, and therefore heavily weighted the unit cost for the initial year. The blank spaces in the chart above indicate that official figures are not available for those years.
† The unit cost of American aircraft was undoubtedly higher than foreign aircraft. 1943, under reverse lend-lease, the cost of the British Spitfire, complete with all equipment, was $45,000, as compared with almost $63,000 for the P-39 and $58,000 for the P-51. It was believed that the difference was mainly in the labor cost.
Thus the AAF was receiving better planes for less money* in 1945 than it had received in 1940 or 1941, and this was accomplished in spite of the fact that many of the costs connected with aircraft production increased greatly during the period. Mass production reduced the man-hours required to manufacture a B-17 airframe from 54,800 in 1942 to 18,600 in 1944 and halved the construction time from the 400th to the 1,000th B-29, more than offsetting the increased cost of labor. By mid-1944 the labor cost per pound of airplane was only about a third of what it had been early in 1941, even though hourly earnings had risen by more than 50 per cent.85
* One reason was the constant supervision and renegotiation of contracts to protect the interests of the government.