Category Archimedes

Predating the wartime cooperatives were a number of formal and informal means for sharing technological information. The Manufacturers Aircraft Association (MAA) had since 1917 served as a means to pool critical aircraft patents. The MAA’s reach did not cover manufacturing technologies though. Nor did it have much influence on military designs, since during the interwar years the US Navy and Army Air Corps could award production contracts to any manufacturer they chose – regardless of the design’s origin. Though not the original intention of the military’s policy, this was a powerful means for spreading leading-edge aircraft design knowledge across the nation’s industry. Manufacturing knowledge, however, depended on more informal channels, occurring routinely through personal communication, trade journals, worker mobility, tooling manufacturers and raw material suppliers, and the occasional act of industrial espionage. It is to manufacturing knowledge that we turn our attention specifically, because it enlightens our understanding of the design and production process.12

One of the more dramatic exchanges of manufacturing knowledge, brought about in part through mobilization, was the large-scale introduction of presses. Job shop production methods of the 1930s involved the manual bending and shaping of sheet metal using brakes, shears, and drop hammers.13 Low production runs did not justify large capital expenditures merely to increase throughput. When orders from England, France, and eventually the United States became significant, and the number of skilled workers proved insufficient to the task, the manufacturers adopted mechanical and hydraulic presses which had long been in use in the automobile industry. Though the automobile industry provided a powerful model for mass production, many of its techniques could not be readily transferred without some measure of adaptation. In this case, not only did aircraft stampings require greater accuracy, but they were in a different material – sheet aluminum versus sheet steel. Aluminum is considerably softer than steel, and exhibits different stretch and spring-back properties. In short, the same equipment could not be universally used in the two industries.

In the late 1930s, Henry Guerin, a department head at Douglas Aircraft, arrived at a way to use hydraulic presses with rubber as one side of a die (Figure 2). Gordon Ashmead, who chronicled aircraft manufacturing techniques in the 1950s, described this innovation:

[The Guerin Process] has been the greatest single contribution to the manufacture of all-metal airplanes. The almost universal adoption of this method of forming sheet metal was the factor that lifted the forming of sheet metal out of the hand-forming category and placed it into mass produc­tion. Most airplane manufacturers give it credit for winning our air war.

While the use of rubber in forming dates to at least the 19th century, Guerin developed techniques that made it appropriate for the aircraft industry. The process substituted layers of rubber for the female half of a die. After workers positioned a sheet of aluminum over the male die, the press lowered the rubber pad and compressed it against the aluminum to the point that the rubber began to flow. The aluminum sheet formed to the male die as the rubber applied equal pressure over the entire piece. Guerin’s process was distinct from earlier methods in that the rubber was restricted to a box that fit tightly around the male die, preventing the rubber from escaping and increasing pressure on the aluminum.14

The presswork championed by Detroit thus had to go through a translation before finding widespread application in the aircraft industry. The Guerin process would have been inappropriate for Detroit, where sheet steel would have quickly abraded the rubber. Not only was the Guerin process matched for aluminum, but it required only one metal die. At a time when tooling departments were working overtime to build jigs and fixtures, a fifty-percent reduction in diework was a welcome savings. Set-up time was reduced as well, since the rubber sheets did not have to be as accurately placed as a standard female die. Typically companies did not require many presses for the Guerin process, as a single large press with moving trays and 24-hour schedules could produce large quantities of stampings. In 1940, for example, Douglas operated a single 2,000-ton press with the Guerin process. As the war progressed, ever-larger presses came into use, including 5,000-pound presses with six work trays wherein a single shift could produce fifteen thousand parts. Ashmead indicates that the Guerin Process was most economical when quantities were between a few hundred and 50,000 parts – within the range typical of aircraft production. The Guerin process found widespread application throughout the airframe industry.15

The Guerin method is somewhat unusual in that most industrial processes were not patented at this time. Many processes were simply unpatentable, and so companies kept information proprietary through secrecy. Other processes, as noted, remained traditions of practice within a company’s tooling department. But even when a patent existed, as in the Guerin case, manufacturers quickly established distinct methods of using it, these too becoming part of local practice and forming a base of tacit knowledge within individual tooling departments. While Douglas’ patent on the innovation was sufficient to inform other manufacturers of the potential for such a process, it did not necessarily ensure good results. Surrounding the Guerin process arose a new body of engineering knowledge regarding its use, involving questions of press choice, die construction and arrangement, and appropriate pressures. The exchange of this accumulated tacit knowledge would eventually take place, but only after months and even years had elapsed, often traveling indirect routes between manufacturers. Typical of these indirect routes would be trade journals, tool manufacturers, and professional societies. In the case of the Guerin Process, representatives from Continental Rubber Works and Brewster Aeronautical (and later Eastern Aircraft – an aircraft division of General Motors) penned a series of articles on the many facets of the technique. Continental Rubber, though not strictly a tooling company, would obviously benefit from the adoption of the process. In this case Brewster and Continental Rubber surveyed different firms’ techniques and published them in Aero Digest, a leading trade journal of the time.16

It was not an uncommon practice for engineers and companies to champion particular techniques through articles and technical updates. With the outbreak of war, however, such indirect means of communication became difficult, as censorship restrictions limited the ability of trade journals to describe the latest technical advancements in detail. In some cases, the Army Air Force found itself reviewing material before publication; in many cases the resulting technical descriptions were so woefully vague that they could not have been of much assistance.17

Still, without other avenues, trade journals and user-producer relationships often provided the fastest pre-war means for accumulating and disseminating such esoteric information. Production and tooling information lacked the numerous channels of exchange that existed for other branches of aircraft technology. Tooling was not a subject for standardization within the Society of Automotive Engineers (SAE) or National Aircraft Standards Committee. As a practical art, tooling had no scientific component, and thus no society like the Institute for Aeronautical Sciences to pursue theoretical advancements. Not only were tooling patents excluded from the MAA, but the MAA agreement and military contracting policy intensified the importance of keeping production technologies proprietary. If significant aircraft design patents were to be shared under the MAA or transferred as part of a military design, it became all the more important to retain a competitive advantage in production techniques.

Aircraft have two main components: airframe and engines. To avoid disasters such as destruction of the second B-29 prototype and crew, February 18, 1943,3 a basic rule offlight test is that only one of these two main components should be unproven. In some cases this is accomplished by having a new airframe design use an established powerplant.4 This is not feasible if the new airframe also requires a new powerplant. Then existing airframes are modified to fit the new engine.

Thus, a B-29 Superfortress was used in 1943 as high-altitude jet-engine test bed for the General Electric 1-16 developed for the X-P59, America’s first turbo jet aircraft.5 A subsonic XF-4D swept wing fighter repeatedly was taken through the sound barrier in tests of GE turbines for supersonic aircraft. For the T-38 supersonic trainer, a modified FI02 carried the diminutive J-85 engine in its bomb bay and, when airborne, the tiny engine would be lowered hydraulically, air started, and then put through its paces. Flight testing of the gigantic J-93 engines for the X-B70 mach 3 bomber used a modified supersonic B-58 bomber with a J-93 engine pod slung in its underbelly (see Figure 12). Once engine development and testing had progressed

[3]

I have tried to relate the issues discussed in the preceding papers to some broader themes in sociology and the sociology of knowledge. I have tried to bring out the role of interests, the need for comparative study and the need for a typology of social forms that can help us see patterns in engineering styles. My aim has been to raise questions and problems of a somewhat more general kind than has been addressed in the papers themselves. The richness of the papers means that there are many possible lines of comment and inquiry that I could have pursued but did not. In particular I have neglected what might be called the political or institutional dimension. This means that I have rather short-changed those contributors who have addressed this side of things. There is much that could and should be said on such matters. For example, there is a whole nest of issues that emerges in these papers about the relation between the so-called ‘free market’ and various forms of government finance and subsidy. Time and again we see the importance of government research and state finance, whether it be tacit subsidy of civil aviation through military expenditure or the research effort of government laboratories. Prof. Roland quotes the figure of 85% of aerospace research deriving from government funding.

A second example, to which I cannot resist drawing attention, is provided by a significant observation made in three of the papers. Profs. Bilstein, Crouch and Hashimoto, respectively, all note how rapidly, in the early years of this century, the British government responded to the emerging phenomenon of the aeroplane. In

The Boeing-Douglas-Vega (BDV) pool was among the first of the major wartime aircraft cooperatives. As a product-oriented organization it illustrates the manner in which engineering knowledge is embedded within a firm. Before the attack on Pearl Harbor, the US government made arrangements for a number of standard aircraft types to be produced jointly by different manufacturers. Boeing, Douglas and Vega were to produce the B-17 bomber, a four-engine Boeing design begun in 1934. Implicit in such an arrangement was that Douglas and Vega would gain access to Boeing’s system of manufacture. Within this system Boeing had many individual production techniques unique to their company, some proprietary, others matters of Boeing’s manufacturing culture. Among the differences noted in the trade journals were Boeing’s drawing system, factory methods, and unique tools.18 To coordinate the three companies’ manufacturing, procurement, design changes, and scheduling issues, they formed the BDV Committee. Begun in May of 1941, the Committee was located in Seattle and included representatives from all three manufacturers as well as the Army Air Corps (later the Army Air Forces after its 1942 reorganization). In addition to a powerful executive committee, three sub­committees operated, including Tooling, Technical, and Procurement, all based in Seattle. Through these committees, Douglas and Vega were given “ready access to all phases of Boeing production.”19

The BDV Committee contemplated a wide-ranging transfer of information, extending beyond aircraft blueprints to include production information as well. Douglas and Vega received all the master tooling and jigs, as well as one complete aircraft and numerous sets of parts for initial production. From their factories in southern California, Douglas and Vega sent scores of workers to Boeing’s Seattle facilities to personally observe tooling construction and manufacturing methods. The extent of cooperation was so great that workers from all three companies joined in building assembly and sub-assembly jigs. Highlighting the relationship between production and organization, an integral part of the technology transfer to Douglas and Vega was managerial information, including major assembly man-hour lists, percentage breakdown charts, schematic drawings with man-hour indications, assembly books, parts cards, and parts list. These were all means for controlling and auditing production flow. Finally, Boeing learned to adopt some of the methods it found in Southern California, such as Douglas’ “production illustration” method.20

The members of the BDV Committee were not entirely unprepared for the obstacles posed by technology transfer. Indeed, they seemed quite aware of the fact that traditions differed dramatically between firms. Regarding tooling, Mac Short, the Vega Vice President of Engineering wrote:

A survey of existing tooling by the Tooling Subcommittee revealed that there was in existence in the Boeing plant a number of small tools for which there were no available drawings. These tools had been constructed in many cases by the workmen on the job during the preceding years of building B-17s. It was the decision of the BDV Committee that these tools represented “know­how” and would be of aid to the Douglas and Vega companies if the information could be transferred to them.

The exchange of such “know-how” was a necessary component of bridging these different engineering cultures. Indeed, the BDV Committee had to create a standard nomenclature for design and tooling engineers since all three companies had, essentially, different languages.21

Still, there was great confidence that the three manufacturers would be able to build identical aircraft. Boeing’s own press releases boasted that “[Boeing, Douglas and Vega] will turn out completely assembled four-engine bombers, identical even to the point of interchangeability of parts.”22 What members of the BDV Committee did not anticipate was the extent to which differing traditions of manufacture as well as conflicting production philosophies would preclude the complete adoption of Boeing’s production system. So long as differences remained, there were bound to be discrepancies between the aircraft produced.

Boeing used what it called a production-density system (later termed multi-line). The process brought nearly complete assemblies together at the very last stage of manufacture.23 Rather than a dominant single assembly line stretching from jigs to the hangar doors, each assembly had its own line terminating at final assembly (figure 3). Most of the installation work on the assemblies was completed before final assembly, meaning that aircraft spent the least amount of time in the stage that consumed the most space. Production-density was considered, “the antithesis of the elongated single production line.”24 The logic behind concentrating on assemblies and sub-assemblies as opposed to final assembly was ably described by Sidney Swirsky, writing with a touch of vitriol in 1943:

That the ideal straight-assembly line for aircraft is, after the fashion of the auto-makers, the final assembly line, is in itself strictly mythical. Actually, the aviation production line must start when parts are received in the form of raw stock at one end of the plant. In order to get more sub-assem­blies to the final line faster, the plant’s board of strategy, including the vice president of manufacturing, the factory manager and the plant layout engineer, must straighten out as much as possible the lines by which fabricated parts and sub-assemblies are to reach the final line. The final

line itself in an aircraft plant is much less a problem than are the sub-assembly lines; the complex­ity of routing and fabricating airplane sub-assemblies is the cause of the ever-threatening bottleneck which can stop production – not straightness or lack of it in the final line, [his italics]25

For Boeing, eliminating the long final assembly line and opting for numerous lines of shorter length had the advantage of requiring less expansive production facilities – one of the original reasons for its adoption in the late 1930s. But as prime contractors for production, not subcontractors, Douglas and Vega were not obligated to implement Boeing’s production-density system. There is no doubt that they benefited from Boeing’s experience, but they were forced to blend Boeing’s aircraft into their own companies’ manufacturing culture. Engineers at Douglas decided that straight-line final assembly was just the thing (Figure 4). Cradled by overhead carriers, workers mated fuselage sections which progressed from station to station down the line. At the first station of final assembly, the fuselage was already in one piece while workers attached the wing sections. Installation of parts and components continued through final assembly. Douglas would later call its straight-line assembly system “Flow-line” and apply it to the A-20 and A-26 aircraft lines. Vega opted for a third system, which it vaguely described as a
“breakdown system.” The focus here was on the fabrication of numerous small pre­assembled components that came together on master jigs. Vega, not unlike the other manufacturers, explained that its system attempted to make the best use of very limited floorspace.26

The result was three different ways of producing the B-17, and an indeterminacy about the best way to mass produce aircraft. An engineer writing on the Douglas system was careful to avoid making comparisons between different production ideologies, arguing that, “Among the many abilities of Americans… is the ingenuity by which different groups achieve similar or identical results, but with widely varying, sometimes seemingly opposite methods.” Unfortunately, the resulting aircraft from these methods were merely similar, and never identical. In fact, in October of 1943 General “Hap” Arnold specifically contacted the National Aircraft War Production Council (NAWPC) about the “non-interchangeability” of assemblies from different companies. He complained that “the different processes employed by the various manufacturers preclude the replacement of a Vega tail assembly by a Boeing or a Douglas tail assembly.” Despite rigid adherence to a single set of master gages and templates supplied by Boeing, differing production ideologies and traditions of practice brought about three different products.27

Figure 4. Douglas B-17 Major and Final Assembly (Building 12 and 13 of the Long Beach Plant). The assemblies and sub-assemblies move from left to right in the bottom building, and then from right to left in the upper building. Source: US Army Air Force, Air Materiel Command, Industrial Planning Branch, “Construction and Production Analysis: Douglas – Long Beach, B-17” (August 1946), exhibits 8 and 9.

While writers lauded the identical qualities of the aircraft in public, the manufacturers privately expressed their concerns about interchangeability within the Aircraft War Production Council. Even companies that were not part of the larger co-production schemes had great difficulty maintaining interchangeability. They attributed the problem to a number of causes, including sub-contractors who, despite having master jigs, often produced parts differently. Within the main airframe firms, they noted the following:

Here a distinct difference in manufacturing processes, tooling, model design, equipment and some small parts exists. The introduction of changes varies. The character of tooling is as diverse as the date, volume, and production rate of each contract, the plant lay-out, type and skill of personnel, climatic conditions, local fabricating habits, and material substitutions and improvisations.

The problems outlined by Hap Arnold were eventually addressed in military specification AN-I-21, which called for various classes of interchangeability. But while the military wanted interchangeable assemblies, sub-assemblies, and parts, such requirements would entail that engineering cultures attain some level of interchangeability as well. Ultimately the Aircraft War Production Council informed the government that the AN-I-21 specification would be impossible to implement across the industry. They argued that because “each company and product presents a specific design and manufacturing problem,” that solutions would need to be equally individualized.28

Despite the lessons of the BDV experience, technology transfer and interchangeability issues remained, even for subsequent cooperative efforts such as the B-29 pool. The Army had chosen the Boeing B-17 and Consolidated B-24 to be the standard large bomber types for the war, but they also sought to place a more modem and capable aircraft into production. This was the Boeing B-29. Like many other aircraft, it would be produced by a group of manufacturers, including Boeing – Wichita, General Motor’s Fisher Division, and North American Aviation. Eventually GM and North American were replaced by Bell (Marietta, Georgia) and Boeing-Renton, with the Fisher Division remaining as a subcontractor. In time, the Omaha plant of the Glenn L. Martin Company would also join the pool. As with the B-17 pool, there was a B-29 Committee established to handle the same coordination problems that arose on the earlier aircraft. Specific details from the B-29 pool give us additional evidence in understanding the difficulties of engineering exchange.

Engineering drawings, when properly rendered, are supposed to communicate all the essential aspects of a design, such that trained workers with appropriate tools can recreate the artifact to specification.29 While Boeing did supply thousands of drawings to the other contractors, all participants understood that these were insufficient to achieve complete interchangeability. Just as a skilled craftsperson uses the same measuring tape for a single project, so did Boeing. The company built master control gages in Seattle which served as the final word on all critical dimensions. These gages remained in Seattle, and were used not to construct aircraft, but to produce other master gages, which in turn would be used to check the accuracy of jigs and completed parts (see figures 5 and 6). Usually the gages bore only slight resemblance, if any, to the assemblies or sub-assemblies to which they corresponded.

Made of thick pieces of steel, the gages were extremely rigid; they conformed to actual aircraft parts at specific reference points – typically locations where a part or assembly would meet another. The B-29 Committee directed the following:

Master gages and master templates shall be used by all four prime contractors and their subcon­tractors to insure interchangeability of all parts which the Air Corps requires to be interchangeable…. Tooling for fabrication of parts shall be such as to insure that all parts are struc­turally and aerodynamically identical. It is not contemplated that tooling be identical. Such prime contractor and subcontractor may construct parts by the method or methods best suited to his shop equipment and practices, consistent with the above; however, the Committee must be assured by the contractor concerned that such tooling will produce satisfactory parts.

In theory, exact master gages distributed to all the manufacturers should have rendered the same parts, sub-assemblies, and assemblies.30

Two situations show the difficulty of using master gages as a way to communicate engineering information. In November of 1942, the B-29 Committee wrote: “Trial indicated that the extremely close angular tolerance required could not be successfully transferred from the Boeing furnished Master Gages.” While the

information about angular tolerances was encoded into the gage, it could not be used to ensure precision in the produced parts. In effect, the engineering information could not be extracted from the gage without the production of additional gages. A more interesting situation developed a year later when the Committee learned of discrepancies between the nacelles produced by GM’s Fisher plant, and the aircraft wings to which they were attached. The nacelles, when placed on aircraft from the Boeing-Renton facility, had attachment holes that were as far as ft a hole diameter off (a very large distance in a precision product). Boeing-Renton checked its own master control gages and found that their own parts were correct, but that the Fischer parts were not. Bell in Marietta experienced the same problems, but oddly, Boeing’s main B-29 plant in Wichita did not. They fit perfectly there and the plant had already turned out nearly 50 aircraft. The conclusion of the Committee was that,

.. .whether Fisher and Wichita are right or wrong in contrast to Boeing-Renton and Bell, it appears that the only practical answer is for Boeing-Renton and Bell to change their hole locations to coin­cide with the nacelles as produced by Fisher. This of course will mean the changing of the master gages at Boeing-Renton and Bell and the changing of the master control gage at Boeing-Seattle to agree with the masters at Wichita and Fisher.

Later, Fisher changed the process after the 210th set of nacelles – such that the discrepancies were removed. Why these particular nacelles fit at Boeing – Wichita was not explained, but it begs a question. If two of the most prominent engineering organizations of the 1940s, the Fisher Division of General Motors and the Boeing Company, could not transfer engineering information via accepted methods (drawings and master gages), what engineering organizations in the US were competent to produce and interpret such materials? Obviously the engineering precision that is supposedly built-in to engineering drawings and master gages must be complemented by not only technical skill, but additional forms of communication as well in order to bridge different engineering cultures. This explains, in part, Bell’s insistence that they be furnished a large quantity of parts so as to hand-assemble their first five aircraft. In addition, they asked for “two fuselages in sections, structure only… one fuselage in detail parts,” and finally a “sample airplane complete with installations.” All of these structures served to educate engineers and workers in a way that drawings and gages could not.31

Where gages were not used, drawings were supposed to suffice. One last incident concerning the B-29 gives us additional insight into the process of technological design. In August of 1942 the Fisher Division complained that it had yet to receive the drawings for the electrical wiring. Boeing responded, saying that such drawings were not produced in final form until after the first few aircraft were built. Boeing suggested that someone be sent from the Boeing Electrical Shop to personally advise Fisher, the implication being that this aspect of aircraft design routinely took place closer to the factory floor. Unlike the aforementioned cases where design and tooling information was somehow lost or changed in the transfer process, here we find that design information accrued as the product took shape. This is not surprising, but it suggests further that design trajectories are not fully determined on the engineer’s drafting table. Technicians, mechanics, and laborers not only misinterpret or lose initial design information, they create it as well.32

The BDV and B-29 Committees were product-specific cooperative organizations. Creating broader industry-wide cooperation fell to a number of groups, the most prominent of which was the Aircraft War Production Council (AWPC). Begun in April of 1942 by eight of the largest Southern California aircraft manufacturers, the AWPC was an unusual departure from normal peacetime competitive operations. It involved the transfer of knowledge, materials, labor, and facilities among former rivals.33 One of the intriguing characteristics of the AWPC was the wide-ranging mandate to share any information that could aid the prosecution of the war. The Board of Directors, composed primarily of the presidents of the West Coast Companies, strongly supported exchange and set a clear policy for Council activities:

It is the instruction of the Board of Directors that members of the Advisory Committees shall be free to interchange all information which will help the war production of the company receiving the information, without regard to protection of manufacturing processes which in normal peace times might be regarded as a secret.34

The sentiment was genuine and followed resolutely by the committees. Like the BDV and B-29 Committees, many of the market-based obstacles normally hindering technology transfer among competitors in peacetime were thus removed. Similarly, the AWPC did not simply lower corporate barriers; it established direct channels for exchange. AWPC Committee workers had strong incentives to cooperate with each other since their immediate superiors in the Council were also likely to be their superiors at their respective companies (see figure 7).35

While never completely isolated from each other before the war, the manufacturers generated much of their engineering information, especially production information, in-house. The principal exception to this was wind tunnel data, the province of affluent institutes and organizations. The challenge for the Council was to establish means not only for sharing information, but generating it cooperatively. Encouraging disparate groups to exploit outside information led to special efforts to tailor information retrieval to the likes of engineers. Mutual engineering research, like cooperative aircraft production schemes, would eventually take on the methodology of standardization in order to make research results portable. The regularity of exchange, while not a direct indicator of

successful technology transfer, indicates that at a minimum there was significant demand for outside information.

As early as 1936, the southern California manufacturers had begun their own in­house technical libraries. With the outbreak of war, it was to the Pacific Aeronautical Library (PAL), begun in 1941, that they turned as the locus for technical exchange. Operated by the Institute of Aeronautical Sciences, the PAL quickly became a natural partner to the AWPC and was ultimately subsumed into the Council itself in 1943. Collection, indexing, and exchange were the library’s three functions, and it became the principal means for publicizing and transferring written information between companies.36

While the PAL did serve as a simple repository, its real strength lay in its ability to make a wide range of materials available to professionals. In October, 1942, the librarians began an indexing project oriented towards engineers and comprising materials well beyond the PAL’s own collection. Finding traditional subject headings inappropriate for aircraft design and production, the librarians created their own. The standard indexes, including the Library of Congress subject headings, the Engineering Index, and the Industrial Arts Index, approached aviation in far too general terms. In consultation with workers from local companies, the librarians exploited the engineer’s lexicon. For example, they classified materials by vendors or trade names rather than under broadly scientific material categories. To satisfy the needs of both the design and production aspects of aircraft manufacture, topics were given multiple entries (for example, one applying to a particular material, another applying to the processes surrounding that material). Furthermore, the PAL attempted to be all inclusive, a single reference point for all matters. The index comprised articles from all the relevant engineering and trade journals, including NACA and SAE publications.37 Eventually the PAL index came to include the collections of member companies, creating a meta-collection available to everyone. Engineers could thus easily order information and have it quickly copied and delivered. Interchange among companies, institutes such as Caltech, and the PAL grew large enough to require a messenger service that traversed a 120-mile route between libraries and companies twice a week.38 The PAL’s indexes were reprinted many times over, being sent to manufacturers across the US and the NACA.39

As table 1 indicates, the PAL served customers throughout the local aviation community. Reinforcing the idea that the PAL acted as an information service, as opposed to a simple repository, is the high percentage of research questions asked relative to other services; they account for over 36% of the total. It is also interesting to note that Vega exploited the service the most, even though it was a smaller company compared to Douglas, Lockheed Aircraft Corporation, and North American Aviation. One probable explanation is that the larger companies were much more self-sufficient, and that the PAL was relatively more important to smaller firms, including subcontractors like Adel Precision Products Corporation and AiResearch. As this was a formative period in aircraft industry subcontracting, technology transfer and the establishment of basic aeronautical expertise would have been critical to these smaller companies.

The operation of a central library fulfilled only a small portion of the Council’s technology transfer goals. A principal objective – eliminating duplicated research among manufacturers – remained for the Council’s committees. The airframe firms continually carried out research in many areas, not just product design, but tests on materials and production processes too. These activities are not well known since the reports were normally proprietary, and tended to be destroyed as newer information superceded the old. They were directed at very specific design and production issues, giving information on how to do something, as opposed to why something occurs. In this, they were quintessential^ engineering, not scientific reports. Table 2 gives the results of the October 1943 survey in which the Engineering Committee found a total of 321 different research projects at all member companies (for an average of 49 projects per company, per month).40 Aside from the sheer volume of research, it should be observed that little of it was in the area traditionally associated with aircraft research – aerodynamics, which had the least number of projects of any other category. Not only was theoretical research a small fraction of the overall research scheme, but studies on manufacturing problems were as numerous as those on design-oriented research. Such research differed from traditional corporate research and development in that it was not restricted to a laboratory setting. What we might call production-design research took place at many levels throughout the factory and

involved a wide variety of personnel, including engineers, technicians, tooling designers, and machinists. The research represented a systematic effort to quickly produce locally valuable design data, including design data for production.

The extent to which companies shared this information with each other can be gleaned from AWPC Engineering Committee statistics. Unfortunately only a partial record of these statistics remain, as indicated by table 3. Many different things

Source: Meeting Report, Engineering Committee, 9 Oct. 1943, Committee Reports on Production Division (September 15 – October 15, 1943), box 24, NAWPC.

Sources: Meeting Report, Advisory Committee on Engineering, 2 Jan. 1943, Committee Reports on Production Division (December 1942), box 22, NAWPC; Meeting Report, Advisory Committee on Engineering, Committee Reports on Production Division (January 1943), box 22, NAWPC; Meeting Report, Advisory Committee on Engineering, 3 April 1943, Committee Reports on Production Division (March 15 – April 15, 1943), box 22, NAWPC; Meeting Report, 7 August 1943, Committee Reports July – Aug. 1943, box 23, NAWPC; Meeting Report, 4 Sept. 1943, Committee Reports Aug. – Sept. 1943, box 23, NAWPC; Meeting Report, 8 January, 1944, Reports on Committee Activities August 1944, box 23, NAWPC; Meeting Report, 6 May 1944, Reports on Committee Activities June 1944, box 25, NAWPC; Meeting Report, 8 July 1944, Reports on Committee Activities, box 25, NAWPC; Meeting Report, 9 Dec. 1944, Reports on Committee Activities January 1945, box 25, NAWPC; Warplane Production 2, no. 3-4 (March – April 1944).

a The AWPC EC number presumably is for information sent to the AWPC EC, since the Engineering Committee would not have been interested in how other organizations were benefiting the AWPC.

b The cumulative figures are those given by the AWPC. This includes some material that is not reflected in the given monthly numbers.

qualified as an incident of engineering exchange, though all of the data listed falls in the information category, as opposed to tooling or material exchanges. For the given sample, exchange between member companies accounts for 60 percent, while exchange with the East Coast accounts for 12 percent, and non-members for 5 percent. Because the Council was specifically interested in the amount of time saved through cooperation, Table 3 does not include duplicated reports. Additional statistics show that many of these engineering reports were reprinted many times over. For example, in August 1943, the AWPC mailed a total of 22,582 articles, 10,193 engineering reports, and 319 miscellaneous publications. Respective totals from the beginning of AWPC operations in April 1942 to the first of September, 1943, 17 months, are: 179, 241; 91,284; and 319.41

Underscoring the inability of written information to communicate all engineering knowledge was the role played by interplant visits. For the months in which they were included in Council statistics, they count for about ten to twenty percent of total exchange. Sometimes plant visits were incorporated into a panel’s meetings. For example the May meeting of the Subcommittee on Tooling Coordination took a tour of the Boeing plants in Renton, Washington. Minutes from the meeting note the following:

The Committee met at 10:00 a. m. and a tour was conducted through both Plant #1 and Plant #2 where the manufacture of roll forming, curving and stretching of sheet metal was in process. The committee was very interested in our methods of manufacture, and special interest was shown in the movable stretching tables built by Consolidated. The tour came to an end at 12:30 p. m. Discussion was then opened on the subject, and Mr. Englehardt, General Foreman of the Metal Bench Department, answered all questions asked pertaining to rolling, curving and stretching of sheet metal parts.42

This kind of interaction represents the height of tacit knowledge transfer. These processes existed in physical form on the plant floor and in the activities of the laborers. Such practices rarely warranted internal reports or studies, and in some cases, might only be known to shop workers. For example, it came to the attention of the Testing and Research Panel that “it is apparently common practice for draw press operators to heat aluminum alloy in warm water just before drawing.”43 Meetings between tooling engineers would have been insufficient to communicate all such facets of a production system. Instead, interplant visits were a crucial method of communicating differences in engineering practice and shop culture. Even in cases where there was published information, plant tours could be highly educational. In one instance, members of the Project Group of the Methods Improvement Panel touring the Northrop factory were able to each try their hand at Northrop’s Heliarc welding process44

On the occasions where the Council found common problems among the manufacturers, it often initiated cooperative research projects, or at least brought existing research groups together. Here again, the critical exchange of engineering information was impeded by differing traditions. In many cases, Council committees and subcommittees resorted to methods of standardization in order to overcome these divides. As such, standardization can be considered a means of achieving technology transfer. For the AWPC, standardization was unlike the SAE’s efforts in the automobile industry, where common parts, materials, and measures permitted external economies. Rather, the standardization of things like test procedures permitted the exchange and comparison of engineering knowledge. It permitted one company’s test results to be compared against another’s. This produced an external economy of a different kind, one based on abstract technical data rather than physical parts or materials. While the AWPC had removed proprietary restrictions on the exchange of data in 1942, it would require standardized company practices before data were truly interchangeable. Standardization efforts did not end there though. AWPC committees standardized language, defects, procedures, and training.

Standardization was not only a means of achieving internal and external efficiencies, it was a familiar method of establishing order and creating novel systems of engineering knowledge. It implied the exchange of best-practice technology as well as the consensual definition of what was appropriate behavior for a worker, an engineer, or a manufacturing firm. The pervasive and continued recourse to standards activities by engineers was due in large part to the fact that this was an extremely familiar form of engineering exchange within the context of industrial coordination. The AWPC committees themselves had been established in a manner very similar to the SAE’s committees, both characterized by technical expertise, small groups with a tight focus, company representation, and industrial coordination.45

CONCLUSION

In the early days of mobilization, it was commonly assumed that America’s industrial strength could be redirected towards the mass production of armaments. In an atmosphere of hopeful naivete, planners believed in a kind of design – production modularity, where one company’s high-performance designs could be transferred to another company’s high-performance production system. Ultimately the country did convert to wartime production and achieve remarkable success in the mass production of aircraft. Yet it required a painful education, one that exposed the extent to which design and production were embedded within a company’s engineering culture and traditions of practice. One might be able to explain away Ford’s well known difficulties in producing the B-24 as simply a case of inter­industry technology transfer, but just as many problems appeared among longtime members of the aircraft industry.

In ways that are often invisible to engineers and managers within a company, the mixing and matching of design and production systems and widespread technology transfer illuminates the nature of engineering information. Engineering knowledge is not solely the province of the research engineer or the product designer. Nor is it embodied succinctly and completely in numerical data or technical drawings. On the way to the final product, information is both lost and accrued. In an ironic turn to the historiography of technology as knowledge, we find engineering knowledge

embodied in physical artifacts, not simply in the final product as we would expect, but in design and production. In tools, machinery, processes, and plant layout, information is perpetuated within a company, reinforcing workplace traditions while simultaneously reflecting workers’ traditions of practice.

The process of production, hidden by scholarly emphasis on product design and performance, complicates our understanding of engineering knowledge. For the manufacturing firm, the ability to design and produce is not the function of a single engineer, but of an organization. We can neither presuppose that design exists outside of production, nor model the factory as a linear process from idea to finished product. Underlying this argument are the different factory actors who execute some manner of design: aeronautical engineer, structural engineer, production engineer, tooling engineer, machinist, foreman, worker, and occasionally, manager. The engineering department may arrive at what it believes to be a complete design, but what rolls out the factory doors will in all likelihood be a different product.

The historical circumstance of wartime cooperation is itself remarkable. The quantity of exchange, where it is documented, is staggering. Both the product – oriented and industry-wide organizations found ways to transfer information, however ungainly they might seem to those who believe in the power of the technical drawing. Drawings were complemented by thousands of master gages, jigs, fixtures, tools, and the occasional example aircraft. Where documents and physical devices could not guarantee precision, these organizations resorted to the exchange of personnel. Interchangeable airplane assemblies were as much a result of practice as they were of accurate measurement. So too, the AWPC promulgated standardized procedures in order to make engineering information interchangeable. Standardization served to expunge critical differences in culture and practice.

What this history tells us is that for many years prior to World War II, firms developed their own ways of doing things. They were content with their handling of engineering information so long as it produced the desired artifact. In manufacturing, companies are held to the success of their product, not the outside reproducibility of their engineering information, as in a scientific laboratory. World War II subjected the production process to new scrutiny as manufacturers attempted to understand why engineering information was not truly portable. In the end they found that production systems were as varied and idiosyncratic as the aircraft they produced.

INTRODUCTION

The “modem” American commercial airport was invented during the two decades before the start of the Second World War. This opening statement has to be written in the passive voice because while it is easy to speak of the invention of airports, there are no inventors – no “Wright Brothers” – responsible for this remarkable technological system which makes commercial air transportation possible. This paper explores a major aspect of the “invention” of airports which was the process of standardization of airport design. In particular, it emphasizes the interaction between and among three separate groups of professionals – engineers, architects and city planners.

The idea that airports were technologies which needed to be designed, let alone something which required the services of “experts” to undertake, did not always exist. Orville Wright argued in a special editorial for Aviation magazine in 1919 that: “The airplane has already been made abundantly safe for flight. The problem before the engineer today is that of providing for safe landing.”1 Few paid much attention to Wright’s pronouncement though. Commercial air transportation entrepreneurs and other aviation enthusiasts wanted to emphasize the image of an airplane whizzing freely through the sky unhindered by all earthly obstacles. Above all else, this preoccupation with unfettered speed worked to eclipse a nascent discussion about the infrastructure needed to transform civilian aviation from mainly a random and recreational activity to a regular and commercial operation.

As various enterprises got underway, most notably the U. S. Post Office’s Air Mail Service, attitudes changed. Whether pilot or passenger (or even just the shipper of a letter or parcel), only the knowledge that it was possible to depart safely and then later return to earth made flight desirable. Consequently, interest in the details – the technical problems associated with safe landing – became paramount. Subsequent sections of this paper describe how first engineers, then architects, and finally city planners came to form a partnership of experts whose coordinated services were required for the design of airports. The creation of this specialized technical community helped fix the fundamental design, shape and purpose of the commercial airport, as well as the technologies and techniques to build and operate them.

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P. Galison and A. Roland, Atmospheric Flight in the Twentieth Century, 301-322 © 2000 Kluwer Academic Publishers.

The few historical accounts of airport development assume (either explicitly or implicitly) a deterministic relationship between airplane and airport. In other words, the size, shape, weight and speed of the airplane determined the physical characteristics of the place for taking-off and landing. Standardization of airport design then, it is argued, is a consequence of the emergence in the 1930s of the “modem” airliner, most especially the Douglas DC-3.2

Closer examination reveals a different story. Powerful political, economic, and cultural forces profoundly influenced airport design; even more than the performance characteristics of airplanes (which for commercial transports only rarely were designed to exceed the capacity of the existing infrastructure). Especially important to understanding this history is the story of the formation of the unusual interdisciplinary technical community responsible for airport design. It would be an alliance among professionals more typically noted for their extreme professional rivalry. Yet, there was more cooperation than conflict and that fact is critical to understanding how airport design was standardized.

This is not to say that there was no professional rivalry but the “struggle” among engineers, architects and city planners was limited.3 The relative harmony came through the steady expansion of the definition of what constituted the technological functions of an airport. Increasing consumer demand for air transportation profoundly shaped the technology of airports. So too did the participation of the federal government. The partitioning of a technological design problem does not necessarily result in positive relations among the participants but in this instance these factors served to mitigate conflicts. At the start of World War Two, this cooperative working arrangement among engineers, architects, and city planners mediated by government officials was manifest in an airport system design that had become a “normal technology.”4

Archibald Black was a budding entrepreneur who found his niche as an airport engineering expert in the early 1920s. Bom in Scotland in 1888, Black emigrated to the United States in 1906 and became a citizen in 1913. His education was something of a hodge-podge, including three years at New York City’s Cooper Institute, plus courses at the Cass Technical Institute in Detroit and Columbia University’s extension school. Black became an electrical engineer and worked on a variety of electrical and construction jobs until discovering aviation in 1910. In 1915 he began working for Curtiss Aeroplane Company in 1915, transforming a hobby into a full-time vocation. Within a year, he had become an airplane designer for Curtiss. In 1917, he took a new job as chief engineer for L. W.F. Engineering Company where he designed the first airplane to incorporate the famous Liberty engine. A wartime stint in the Navy brought him to Washington where he was put in charge of preparing all of the Navy’s aeronautical specifications.5

After the war, he began a long and productive career as a consulting engineer. Over the decade he would emerge as the most influential figure in the design of

American airports. But it was with much bravado that the 33-year old would assert in a letter to Secretary of Commerce Herbert Hoover that: “in addition to being the most experienced consulting engineer in this field in the country, the recent dissolution of a competing firm now makes ours the oldest also.”6 It was a bold claim that said more about the newness of aviation than it did about Black’s engineering expertise.

Still, within a year, Black had managed to gain quite a bit of attention for himself. His article, “How to Lay Out and Build an Airplane Landing Field,” appearing in Engineering News-Record, was selected for reprinting by the National Advisory Committee for Aeronautics in its Technical Memorandum Series. Aerial Age said the paper was “probably the first really constructive discussion of the subject published.”7 Black, who had spent much energy beating the drums in a generic pitch for the contributions engineers could make to aviation, suddenly found a rhythm which resonated. While he never lost his broad interests in advancing commercial air transport, Black became a champion for “scientifically arranged landing fields in America.”8

In 1922, landing fields (the word airport was not in common usage until the late 1920s) for airplanes did not seem like much. In comparison with the stupendously complex civil engineering design projects for bridges, tunnels, canals, railroads, and hydroelectric dams, the small square (usually) sod fields with a wooden hanger, a gas tank, and a wind cone hardly seemed to demand the services of an expert, let alone a specially-trained engineer. Appearances were deceiving according to Black. Even in his earliest articles, he argues for careful planning based on significant technical knowledge of civil and mechanical engineering, meteorology, and construction technology. The term “scientifically arranged” referred only to the design of a facility which enabled aircraft to get in and out of the air.

Thus, Black’s early articles emphasize that the shape and size of the plot required the detailed scrutiny of meteorological data. The sky was not benign and aircraft were fragile. Soil samples were required to design the surfaces for take-off and landings. Regular use required a prepared surface able to bear the loads exerted by an airplane. There were formulas for calculating the impact of obstacles such as trees or tall buildings, landing gear stresses, and how much grass seed should be sown. The type and arrangement of buildings needed to be optimized for safety and functionality. And finally, it was necessary to develop various communications systems that enabled ground personnel to relay vital information to airborne pilots.9

Black was not the first to suggest these things, however. Desperately casting about for a postwar mission, aviation officers in the Army embraced the idea of sharing with the public the knowledge gained during the war. Right after the war the Army had decided to plan its own national airway system and had begun to survey potential sites for airports. That work was endorsed by President Harding who stated during a special message to Congress in April 1921 that the Army Air Service should take the lead and aid the “establishment of national transcontinental airways, and, in co-operation with the states, in the establishment of local airdromes and landing fields.”10

Harding’s pronouncement led to the establishment of the Airways Section within the Training and War Plans Division of the Air Service the following December and the creation of a “Model Airways” program in June 1922. Fulfilling its obligation for the “promulgation of information pertaining to airdromes and airways,” the Air Service issued “Airways and Landing Fields,” a new Information Circular in March 1923.11

Like its earlier “Specifications for Municipal Airports,”12 this Army circular includes details about what constituted an ideal landing field. The Army “ideal” was developed in the context of an expanded model airway that served, first and foremost, military objectives which were to provide for the aerial defense of the nation. The Army had included in the specifications for its very first airplane (ordered from the Wrights in 1908) that the airplane be easily disassembled and, preferably, easily shipped in a standard Army wagon crate 13 After the war, however, the Army expected to be able to fly from base to base. The typical range of aircraft in the early twenties required frequent stops (indeed, the working assumption of the time was that safety required an airfield every 10-25 miles). Lieutenant F. O. Carroll, a Landing Field Officer for the Army Air Service, wrote that the Army would follow along the same routes of the Conestoga pioneers and continental railroads. His challenge was to “arouse the interest and secure the co-operation of the cities in this important national enterprise, and make them see that their future and the future of the country depends on the establishment of landing fields.”14

What the Army wanted most of all was air fields that conformed to a set of standards. Recognizing that all communities could not afford to build the same sort of facility, the specifications proposed four classes of landing fields. A fourth class field was for emergency use only; its landing surface might be just a narrow strip of land about 600 feet in length. The very best, the first class field, would be a square field at least 2,700 feet in any direction. The surface for landing and taking-off would be improved – level, smooth, sodded and well-drained. All approaches to the field would be free from obstacles such as telephone poles, electrical lines, trees and tall buildings. The field would be well marked with a landing circle (a large white circle, 100 feet in diameter, set into the ground), wind direction indicators, and the name of the facility in 15 foot high letters. Finally, a well-developed field had hangars, shops, gasoline, oil, telephones and transportation to the nearest town. Second and third class fields had slightly smaller dimensions and fewer amenities although standards for marking the field remained the same. There was little change in the basic requirements for air fields between 1920 and 1922, although the “square” field design was no longer the only preferred landing field shape – An “L” shaped field was considered almost as good as the square-shaped field.15

There were some who felt the Army’s vision for airways and airports left something to be desired. It was not the generic vision of a well-functioning system of airports and airways that was problematic to these individuals. Rather it was the belief that the Army’s own airfields had little to commend about them and that most Army officers were unable to render good advice on how to design and build an airport. The leading critic was the engineer, Archibald Black. Black’s main purpose in making his complaint was to lend support to his conviction that the best possible training for a would-be airport designer was engineering. Pilots, of course, had a great interest in airports, but Black believed that merely possessing the skill to pilot an airplane was not adequate qualification to design an airfield.16

Black actually had three related concerns. His first concern related to the quality of existing Army air fields. The tremendous urgency to build military air fields during the war had meant relying on firms which had neither experience in designing and building such facilities nor the time to make a thorough study of the problems that were unique to aviation. This observation was not intended to be an indictment of either the Army or the construction companies. Rather, Black believed that given the poor result there was “no reason for ignoring past experience and common sense, and arranging fields without careful consideration of the entire subject beforehand.”17

Black’s second concern about relying on the Army example was that subsequent to the war, some of the fields the Army had completed were of very high standard – too high to be meaningful for the average municipality. “Army equipment,” he wrote, “is considerably more elaborate than is likely to become necessary at municipal fields for some time.”18 In one article scrutinizing various airport designs, Black was equally critical of fields that were too large or elaborate as he was of small or “carelessly” organized layouts. The former represented unforgivable profligacy with public monies; the latter were safety hazards.19

Black’s third and most doggedly asserted criticism was reserved for “the customary practice of consulting some local hero, in the person of a former Army pilot.. ..”20 The veteran pilot while worthy of veneration was unlikely to be familiar with both air field design and current commercial aircraft technology. Black repeated this assertion at every opportunity. In American City he wrote, for example, “it is more advisable either to obtain the services of a specialist or to appoint, as a substitute, a well-rounded committee to do the planning. Any other policy may prove surprisingly expensive at some later date and the cost may be counted in human lives as well as in dollars.”21

The resolution to all these concerns, according to Black was to establish airport design as an engineering function. Thus, the essence of good design was one which placed safety paramount, followed by the careful expenditure of funds.22 His fullest statement on this subject was in an article written for Landscape Architecture in 1923. The piece, “Air Terminal Engineering,” began: “The selection, arrangement and construction of aircraft landing fields and other types of air terminals represent an entirely new phase of engineering which is yet very much in the paper state.”23 The benefits to relying on an “airport engineer” were three-fold. First and foremost, while a bad design would absolutely result in crashes, a good design would prevent costly accidents. Second, good design would result in the best overall construction price. And third, Black believed an engineer was best suited to determine the airport location, as well as to plan the buildings at the facility to take advantage of existing ground transportation and power, water, and telephone utilities.24

Black had recently returned from a European study trip and his head was swimming with details related to airport construction. It was in Europe that he first formed the belief that airports ought to be engineered. He was especially enthusiastic about the developments at Croydon Airdrome in London. There were three airports in London but Croydon had become the city’s main commercial facility after the war. Black was undeniably impressed by what he saw but two things seem to have been especially influential – Croydon’s airport lighting system and its carefully designed landing area surface.25

In his influential Engineering News-Record article, it becomes especially clear why Black believed airport design should be done by engineers. In this article, Black makes a strong case for special analytical skills an engineer might bring to the problem of design. Existing grass fields were fast proving inadequate. As the number of airplanes taking off and landing at any given airport increased beyond a small handful, the sod-covered surfaces rapidly disintegrated. Airplanes of this period were all “tail-draggers” and their skids carved deep gouges into rain-softened surfaces. The Army had experimented with concrete landing and take-off crosses. Black urgently warned readers about the pitfalls of concrete as a landing surface (it was fine for taking off). In addition to the great expense, it was too smooth for an era when airplanes did not have brakes and pilots relied on a rougher surface to slow down the vehicle.26

There was a prevalent misconception that turf was “softer” than concrete and therefore safer. Black dismissed such ideas. The landing gear and tires of an airplane were designed to bear specific loads; one surface or another made little difference to the airplane (assuming the initial design was adequate). Based upon Black’s analysis of airplane tire sizes and their normal loads, he readily concluded that most landing surfaces were not adequate. He became an early advocate for “runways,” special strips 75 feet wide and 1000 feet long. Runways were part of the larger landing surface area but they would be specially designed and constructed to carry the full load of an airplane during take-off and landing. This necessitated careful preparation of the subgrade as well as some kind of special surfacing. It also required renewed attention to drainage matters. Conventional roads relied on crowning as the central element of drainage design but Black found that such curved surfaces were very hazardous.27

Black pursued his studies of runways, consulting with highway engineers as well as experts at the Bureau of Public Roads. In later articles (and books) he provided much more substantial discussion of runway surfaces as well as providing specifications and cost analysis information.28 These articles were of noticeably different character from the literature being supplied by the Army which continued in the “do-it-yourself’ manner. What Black wanted to demonstrate was that airport design would only mature when the designers were able to comprehend fully the assumptions and methods employed by aircraft engineers in the design of airplanes. Black, who had spent several years designing aircraft, believed that the symbiotic relationship between airplane and airport could be best characterized in engineering terms – in a language of speed, power, weight, size, wing loading, power loading, lift, drag, and aspect ratios. The development of airports and airplanes needed to proceed in a coordinated fashion or commercial aviation would falter. These lessons became especially ingrained during his tenure with the group of engineers writing the Aeronautic Safety Code. By 1925, it was clear that Black had made his point, although the full impact of it would not be perceived until the passage of the Air Commerce Act in May 1926.29

Archibald Black was just one engineering consultant, and one advocate, or even a handful, does not a community of experts make. The aeronautical engineering community had begun to sprout small clusters of “experts” located in the university, industry, and the government. But with the exception of the Model Airways project of the Army, emphasis among engineers was almost entirely on airplanes.30 The powerful political currents swirling around the aviation legislation debates of this period had finally reached a consensus that the federal government had a leading role in stimulating and supporting the development of both military and civil aviation. Through the Air Commerce Act of 1926, Congress put most of the responsibility on the shoulders of the Commerce Department. With regards to airport development, Congress placed a severe handicap on the new Aeronautics Branch. The Air Commerce Act of 1926 expressly prohibited the Commerce Department from providing any financial support for airports. Yet despite having no financial resources or regulatory powers, Congress still included a specific provision in the law requiring the Commerce Department to examine and rate airports.31

Fulfillment of this obligation was not considered a burden, although without the power to mandate that all airport facilities participate in a ratings program the law lacked much punch. Still, the Aeronautics Branch was established amidst the heady intellectual fervor of “Fordism” and “mass production.” Commerce Secretary Herbert Hoover was a leading proponent of standardization in all industries so it is not surprising that department officials would place heavy emphasis on standardization as a crucial first step in transforming commercial aviation into a large scale transportation system. The Airport Rating program, one small part of a much larger regulatory program being initiated by the Department, was animated by similar standardization objectives. Airport Ratings helped ensconce airport engineers as the primary technical experts and deeply influenced the process and outcome of airport design. Thus even without the power of the purse, the Aeronautics Branch managed to become an incubator for the professionalization of airport design.32

The ratings, introduced in 1927, represented neither original nor dramatic reading. The crucial fact was that there was now a single coordinating body in the nation.33 Compliance was strictly voluntary but the Aeronautics Branch had now asserted a role in defining, what Lester Gardner called in his speech to the Fourth International Congress of Aerial Navigation in 1927, “airport excellence.”34 The new federal standards were largely identical with those of the Aeronautic Safety

Code. They included a set of basic minimum requirements for every field under consideration for a rating. The ratings scheme established borrowed the highway engineer’s “stage construction” practice meaning that they allowed for construction to proceed in “stages.”35 This helped address the fact that, because airport construction had been deemed a municipal function, individual airports were never going to be identical. As the Army had discovered, communities did not have the same financial resources or the same degree of interest. But more importantly, the air transportation companies found that 100 percent uniformity was unnecessary – air travel was clearly heavier between certain destinations for reasons independent of the quality of the airport. The primary concern for federal officials, then, was to provide a base-level of uniformity.

The ratings system was greeted warmly but ironically no airports made an application until 1930. The reason was that the system was voluntary. Austin MacDonald summed up the situation as follows: “Those responsible for the destiny of an airport are usually disinclined to accept anything less than the very highest rating issued. Rather than be branded as inferior, they are likely to defer their rating application, hoping that at some future time they will be able to meet all requirements and receive the unqualified approval of the Federal Government.”36 Still the effect of Airport Ratings was almost immediately apparent in airport design.

A stunning example was the Oakland, California, Municipal Airport which was a carbon-copy of the Commerce Department specifications. Oakland was the first major airport designed and built after the Aeronautics Branch had developed its airport ratings. Opening in 1928, in every aspect of its design – from drain tile and grass seed mixtures to hangars, lighting and hospitals, even the painted markings on the building rooftops – the Oakland airport conformed to the specifications listed in the standards for the highest airport rating. Even its physical layout was identical with the sketches of a model airport supplied along with the airport ratings. Oakland’s subsequent success as a working facility became strong testimony on behalf of the “engineered” airport. As an airport construction boom stimulated by Lindbergh’s epochal solo Atlantic crossing got underway, letters began to pour in to the Aeronautics Branch requesting advice on how to locate an airport engineer.37

Unlike the engineers who were involved in aircraft design, there was no laboratory or university environment in which the merits of different kinds of designs could be debated. There was only a very limited public discussion stimulated by the articles which appeared in various journals. When the Branch formed a special Airports Section in February 1929, one of the central functions of the new section was to become a clearing house of technical information (although there was no promise to provide any critical analysis of that information before dissemination). The ranks of airport engineers swelled and an examination of all airports built during this period clearly indicates that there was a general consensus as to what constituted “good” design versus “poor” design.38

Three factors were considered when making such judgments. First and foremost was pilot opinion coupled with the accident rate at a given field. Traffic volume was the second measure. Finally, profitability (or at least the ability to break even) was used to evaluate airport design. The consensus built around these indicators was strengthened with the establishment of professional organizations dedicated to airports. In May 1929 the Aeronautical Chamber of Commerce’s new Airport Section sponsored the first national airport meeting in Cleveland. Over three-hundred attended the Ohio meeting and another three – hundred attended the five regional conferences held in Boston, Atlanta, Los Angeles, and Bridgeport. Somewhat immodestly, though true, the Chamber concluded that “the minutes of the meeting and records of the papers read constitute a compendium of thought and experience on airport development from the best minds in the field.”39

But amidst this expanding professional interest, airport engineers suddenly became aware of a challenge to their fledgling claims of expertise. This challenge appeared not to question the engineer’s skill but rather it resulted from a renewed professional interest within the American architectural community for airports and airport design. City planners, too, began to take a vocal interest in airports. While ultimately it would be understood that airport design was sufficiently complex to require the skills of several different professionals, this was not true at the start.

Yet, airport engineers did not take long to concede publicly that there was a role for architects in the design of certain airport buildings. Philip Love of Love-Sultan, stated in a paper for the Third National Meeting of the Aeronautic Division of the American Society of Mechanical Engineers that: “At first, airport buildings were hard to treat architecturally, but a definite type of characteristic “airport” design is coming to the fore rapidly, and we are learning that sympathetic treatment of mass and color will give buildings a really pleasing appearance without exorbitant cost, and the whole industry has ascended to a plane where this is not only justified but demanded.”40 That nervous acknowledgment came at an important turning point in the next phase of airport design – the integration of architects into the community of experts that designed airports.

At the end of World War I, a British Design Panel had been formed to investigate stress and aerofoil performance.44 The Panel’s main concern soon came to focus on scale effect. At its second meeting, after a long discussion, the Panel concluded that the scale effect was important. The Panel decided to state its own opinion formally as soon as possible.45 An RAE group under Wood summarized the relevant experimental research on this subject.46 Wood’s preliminary report noted a considerable difference between full-scale and model data for lift, drag, and center of pressure. It was decided, however, to defer a final recommendation while awaiting the arrival of still more comprehensive data.

After a year of preparation, the RAE group submitted its conclusions on scale effect in February 1923.47 By then, Glauert was actively introducing German aerodynamic theory and the International Trials were taking place. The RAE report included Prandtl corrections to its research data. This application triggered a heated debate first with the Design Panel and then with the Aerodynamics subcommittee. Introducing the RAE report as a part of the general investigation into the scale effect, Panel Chairman William S. Farren highlighted this first use of Prandtl corrections by British researchers. Farren himself was not in favor of the correction, because he considered it scientifically more desirable to compare results of full-scale testing with those of wind tunnel testing modified only through “purely experimental corrections.” Before the meeting, he had consulted two Main Committee members on this matter, and reported their disapproval of the correction to his own Panel members.48 Farren clearly recognized that the question concerned a fundamental principle of experimental procedure.

In response to the Chairman’s comment, Wood stated that the Prandtl correction had already been confirmed by the International Trials and was regarded by the RAE as part of routine wind tunnel experiments. Glauert agreed with Wood, and cited as a parallel case those corrections due to the interference of wires, which had long been regarded as valid. But their arguments were not sufficiently persuasive. R. V. Southwell, Superintendent of the Aerodynamics Department of the NPL, contended that the Prandtl correction should have been applied in a different section of the report. Of the four sections of the RAE report, the first two dealt with results of full-scale and model experiments, the third with the comparison of these two results, and the last with some applications of Prandtl’s theory. He suggested that Prandtl corrections should have been used and discussed in Part 3 instead of Part 2. He added that the NPL would soon be in a position to confirm experimentally the values given for the correction.

The Design Panel deferred judgment on the validity of the application of the Prandtl correction.49 The Aerodynamics subcommittee discussed the matter the following month.50 Despite the Chairman’s initial comment that the application of the Prandtl correction was already standard practice at foreign laboratories, most members of the subcommittee disagreed with the manner of presentation employed by the RAE group. These scientists, including Bairstow, Farren, Jones, and Glazebrook were all emphatically of the opinion that it was undesirable to give figures to which “purely theoretical corrections” have applied. Corrections to raw data were sometimes made, they argued, but “such correction was based upon actual observations, and was not of the same nature as the Prandtl correction.” Southwell called attention to the fact that the application of the Prandtl correction was not yet standard practice at the NPL. He announced that their on-going experiment on a biplane in the four-foot wind tunnel could check the validity of this correction.

Lacking Glauert’s support, Wood’s argument in defense of the Prandtl correction was insufficient to persuade all these critics. He merely mentioned that the correction for tunnel walls was usually made in experiments on propellers. Finally, on the chairman’s motion, the following recommendation was approved: the general practice should be to give the actual results both in the form of figures and tables, while results to which the Prandtl correction had been applied could also be added at the discretion of the authors. Further discussion of the validity of the Prandtl correction was postponed until results were obtained from the NPL experiments.

Two months later, however, Southwell wrote to the ARC Secretary that the NPL was not yet in a position to provide decisive results. He asked that the Committee discuss this matter during the summer vacation so that the NPL staff could initiate the program promptly in the fall. Following his request, the Aerodynamics subcommittee decided to initiate two types of experimental investigations, both intended to test experimentally the accuracy of the Prandtl correction.51 The first experiment involved testing a model in both a four-foot and a seven-foot wind tunnel so as to determine the difference in results due to the interference of the tunnel walls. The second experiment was to visualize the air flow behind airfoils of different spans in order to determine to what extent Prandtl’s theory was “substantiated.”52

Based on the results of the NPL testing, Glauert submitted a report in November entitled “Experimental Tests of the Vortex Theory of Aerofoils.”53 The report concluded that the NPL results experimentally confirmed the accuracy of the Prandtl correction when applied to wind tunnel results on certain wings. The agreement between tests done in wind tunnels of different size when the Prandtl correction was applied was indeed much more striking than had been the case with the French results in the International Trials report. At the subcommittee meeting, these positive results impressed every member.

Yet some reservations continued to be expressed. G. I. Taylor questioned the scientific grounds of this confirmation, asking whether the effect was due to circulation or to the eddying of air around the airfoil. Taylor was asked by the chairman to discuss this matter with the NPL staff.54 The next month, Taylor submitted a paper dealing with this question and with Glauert’s treatment of Prandtl’s circulation theory.55 At the beginning of Glauert’s paper, Glauert had mentioned experimental confirmation very briefly. He cited the measurement of air flow around an airfoil at the NPL, showing that the circulation around the airfoil was independent of the area of the chosen contour; its value was very close to the theoretical value. In discussing this argument, Taylor pointed out in his report that if the contour was selected in a special way, the experimental results cited by Glauert would be obtained no matter whether resulting from the circulatory flow or the discontinuous stream flow. The observed results, therefore, could not be taken as confirmation of the physical hypothesis of Prandtl’s theory. As Taylor stated, his discussion was intended to “see how far evidence of this kind may be taken as confirmatory of Prandtl’s theory,” and added that his comments were “very probably well known to followers of the work of the Prandtl school.”56

After Taylor’s brief comment at the Aerodynamics subcommittee meeting, Bairstow and Horace Lamb expressed their own doubts, stating that they were not certain that the corrections calculated by the Prandtl theory were really accurate. They therefore considered it undesirable to change the method of presentation of wind tunnel results decided upon at the July meeting. Wood responded by referring to analogous corrections which were made for experiments of propellers and airships in wind tunnels of different sizes. Bairstow then made a proposal on the manner of presentation, which was seconded by Lamb. According to this proposal, the following method should be followed:

1. The numerical results of wind tunnel tests should be presented without the Prandtl correction.

2. A statement should be made as to the amount of the Prandtl correction.

3. The diagrams should be drawn from the results obtained after applying the Prandtl correction.57

Farren and Jones, both faculty members at Cambridge University’s Aeronautical Department, suggested that the proposal be amended so that instead of the old method as prescribed in the first term, the numerical results would be presented in a form to which the Prandtl correction was already applied. Farren and Jones thus changed their view on the Prandtl correction, and came to side with Wood and Glauert. Bairstow then slightly modified their proposal so that numerical results without the Prandtl correction were presented together with additional columns containing the same results with the Prandtl correction applied.

The result of the vote was very close, seven to six in favor of Farren’s and Jones’s amendment. The Aerodynamics subcommittee thus agreed to recommend to the Main Committee the following method of presentation:

The authors of reports describing wind tunnel tests should present their results… in a form after the Prandtl correction was applied. A statement would also need to be added as to the amount of the Prandtl correction.58 Glauert’s report was approved for publication.

Shortly afterwards, the Design Panel convened to discuss what manner of presentation it would use for its final report on scale effect. Southwell expressed his strong opinion on “the necessity for dispelling any impression that the Committee thought scale effect should be zero.”59 It was obvious to every Committee member that the statement was a criticism of the previous report of the “Scale Effect” subcommittee and of Bairstow, who had insisted on the insignificance of the scale effect as well as the inclusion of an explicit statement on such evaluation in its final report. Following Southwell’s suggestion, the Design Panel decided to include a brief history of the problem in its final report, pointing out that the application of the Prandtl correction caused “a marked improvement in agreement” between full-scale and wind tunnel tests.60 The controversy over the scale effect was finally settled.

A few years later, the Scale Effect Panel was formed. This time, the scale effect was not enclosed in quotation marks. Ironically, Bairstow was selected for its chairman.61 The task assigned to the panel was twofold: to study the scale effect as well as to examine the advantages of the use of a variable-density wind tunnel. This new type of wind tunnel had been developed by the NACA to reduce the scale effect.62 The tunnel was placed inside an air tight tank to create an aerodynamic condition with the same Reynolds number as in full-scale flight. The construction of this wind tunnel was based on the realization that the scale effect was now a significant factor to be taken into account. The panel was unanimous in recommending the construction of this new wind tunnel, and submitted the conclusion that it be constructed as a project for the program of 1928-29.63 The Main Committee sanctioned the project.

During the summer of 1928, D. R. Lane, a staffer for the new trade publication Airports, made an extensive survey of airports between San Francisco and Chicago. In an article about the trip, he wrote: “On this journey only three airports were seen at which there were real provisions for passengers to wait in comfort for the arrival of planes. These were the ports of San Francisco, Oakland and Detroit (Ford Airport) where there are comfortable waiting rooms in the administration buildings.”41 Of the three, Lane asserted that the terminal building at the Ford Airport was “probably the best airplane passenger station yet built in America.”42 That assessment was often repeated during the next couple of years including in Domestic Air News, the Aeronautics Branch’s bi-monthly publication which published an article that stated unequivocally: “The Ford Airport at Dearborn is one of the few real airports worthy of the name at present in operation in this country.”43

The Ford Terminal, which opened in November 1927, was a two story square white brick building with Spanish tile roof. Almost the entire 2,700 square feet of the first floor was given over to a passenger waiting room. The second floor, which was smaller than the first, housed the offices of Ford Air Transport Service and Stout Air Service. The most admired feature of the building was its wrap­around balcony from which visitors could watch all the action on the field. Pictures and various reports suggest that the passenger space was considered very comfortable with armchairs, tables, and separate lavatories for men and women. Lane made a special effort to point out this last feature, noting that it was “embarrassing to a woman passenger to be required to pass through a hangar where mechanics are at work.”44

There are two things which are historically important about the Ford Airport Terminal building. First, was the fact that it won rave reviews throughout the industry.45 Second, was that the building was designed by an architect. Henry Ford’s main concern was that his airport always be thought of as the best airport. The new business of carrying passengers did not automatically require the construction of a terminal; prior to the 1930s, most passengers simply walked from the airplane into the hanger or administrative offices. Ford Airport did not have even these facilities; it abutted two factory buildings. In fact, when the airport was first opened, passenger-carrying and exhibition flights required special advanced permission. The addition of regular passenger service to the mail service originating from Ford Airport changed this. Henry Ford encouraged those running day-to-day operations at the airport to stay abreast of new developments.46

Supplying a special building for passengers was one of those “new things” that needed to be provided for. However, Ford did not turn to an engineer to design the facility. Nor did he consult with the many ex-Army pilots in his employ. He turned to an architect. Henry Ford was not the first to employ an architect to design an airport building. However, the extremely high profile of the Ford Airport meant that developments taking place in Dearborn were viewed as bellwethers by the aviation community.47

In April 1928, two editorials about airports and architecture appeared – one in Scientific American and the other in the debut issue of Airports. The Airports editorial argued eloquently that “Aviation has found its niche in the activities of man. The airport is a potent factor in aviation’s success. A definite program of design and construction must be followed if we are to build our airports for posterity.”48 Alexander Klemin, writing his debut column on new development in aviation for Scientific American, stated: “We are apt to think of an airport as a large landing field with a group of ugly looking hangars at one end, a runway or two and a system of lighting.”49 Both pieces concluded with a call for an international architectural competition. However, while Klemin (who was greatly impressed by the results of two such competitions in England and Germany) thought this was a great solution to encourage American architects to become interested in airport design, the editors of Airports were more timid in advancing their idea. “There must be many Chambers of Commerce, municipal authorities and private individuals,” they wrote, “who will look with favor upon a plan of this kind. Others may deem it premature, destructive and incongruous.” The final question the editors posed to readers was: “Should it [employing architects to design airports] be encouraged?”50

Architects, no less affected than other Americans by the Lindbergh frenzy, seemed to need little encouragement. In May 1929, Architectural Record published “Airport Design and Construction,” a lengthy feature article by Robert L. Davison.51 Davison’s purpose was to summarize the state-of-the-art as well as to suggest the fundamental principles which would govern an architectural approach to the problem of airport design. While he believed that the flying field was still the province of the engineer, Davison claimed the buildings for the architect. Thus, Davison’s article was largely a primer in aeronautics – incorporating the Department of Commerce airport rating requirements, specifications of airplanes, design information about existing airports, and so forth. And even though the basic facts about aviation and airports constituted nothing new, Davison’s piece was unlike anything ever produced by airport engineers.

One key difference between the architectural and engineering approach to airport development was centered in the design process. Both architects and engineers found it necessary to make assumptions. Among practicing airport engineers, however, assumptions often remained unstated. For example, both architects and engineers discuss the problem of selecting a good site for an airport. Both give extensive descriptions of various features which must be considered before picking a site. Yet almost all of the articles written by engineers are seemingly diffuse. Gavin Hadden wrote that: “It is impossible to describe an exact set of conditions which will govern every airport design. The natural conditions alone – geographical, topographical, meteorological – present widely differing influences on specific problems and if to these are added the manmade conditions, which affect every site and its requirements, and which will further affect present requirements and future predictions, the variations may be multiplied many times.”52

Davison, by contrast, presented a short, succinct listing of requirements – for the flyer and the public. Each item on the list was assigned a point value. To pick a site, one simply checked each item on the list, assigned a value (up to the maximum assigned to that item) and then tallied up the total points. For example, “freedom from dense river fogs” was equal to an “8” so a value might range from “0” (always fogged in) to “8” (never subject to fogs). On the surface, Davison’s table may seem the more rigorously analytical of the two. Yet, the procedural difference between Hadden and Davison was actually a function of priority. Site selection was one of the most important problems of the entire design process for engineers, but far less so for architects. This was because airport engineers were almost exclusively preoccupied with the problems of safe take-offs and landing. Architects were focused on the new problem of transfer – the shifting of passengers and cargo from one mode of transportation to another.53

The story recounted here was, in sum, about the success and the failure of Leonard Bairstow. The whole story turned on the scientific and technological significance of the key instrument for aeronautical research: the wind tunnel. Bairstow made full use of it, defended the validity of the data from it, and argued for the continuation of model research in it. He further promoted the attempt to standardize the performance of wind tunnels all over the world and to accord the NPL a central role. For all these efforts to connect the inside and the outside of the laboratory, I compared him to a laboratory director in Latour’s Science in Action and Pasteur in Pasteurization of France.

At first, Bairstow was exceptionally successful. His prewar stability research was applauded at home and abroad. Despite an American request, the British regarded it too important to disclose. Through such accomplishment, Bairstow attained fellowship in the Royal Society, served on the Air Board, and became Professor of Aeronautics at Imperial College. He became an extremely powerful figure in the British aeronautical community.

Bairstow’s position would have been further enhanced had the NPL model of wind tunnel research been standardized around the world. That was one object of the decade-long International Trials project. During this project, however, it turned out that Bairstow’s previous argument for ignoring the scale effect was called into question. Prandtl’s new aerodynamic theory challenged Bairstow’s position. French use of the Prandtl correction sparked a scientific debate on the validity of Prandtl’s aerodynamic theory. Acceptance of the Prandtl correction implied criticism of Bairstow, who had insisted on the negligibility of the scale effect.

While Bairstow served as an excellent middleman between theoretical scientists and practical engineers in conducting model research on stability, he failed to be such a middleman between Teddington and Famborough. He might have been more sensitive and generous to the full-scale experimenters at Famborough, initiating a theoretical and experimental research program on scale effect. Instead, he defended his model research like a lawyer at court by pointing out possible weaknesses in full-scale testing. Perhaps the wartime emergency and the position of the Air Board prevented him from taking a more discreet stance on this matter. In any event, he left himself open to later criticisms and repudiation. In the end, the renamed Scale Effect subcommittee approved the desirability of constructing a new variable-density wind tunnel developed by American engineers. This was a clear judgment that Bairstow had been wrong.

If we take Latour’s argument seriously, we could pose a question. Why did Prandtl’s theory prevail in the postwar world? From 1904, when he arrived at Gottingen, to 1918, the year of armistice, Prandtl succeeded, like Bairstow, in conducting aerodynamic research and expanding his research facilities. But after the war, he was placed in severely limited conditions on poor financial and material bases and with almost no communication with foreign investigators. Yet his aerodynamic theory soon won over aeronautical engineers all over the world. It was mainly not through Prandtl’s own effort but through the efforts of foreign engineers, and his disciple in the case of the United States, that his theory was accepted worldwide. In this connection, we could turn our attention to the RAE engineers who championed the introduction of Prandtl’s theory in Britain. In arguing for the validity of the German theory and specifically promoting the application of Prandtl correction, they succeeded in restoring the position held by their colleagues at Famborough in the wartime scale-effect controversy.64