SP-4306 Engines and Innovation: Lewis Laboratory and American Propulsion Technology





[127] In 1958, when the NACA became part of NASA, NASA became its own principal customer. It supervised contracts with industry to provide NASA with hardware for space exploration. During the NACA period Lewis Laboratory's relationship with industry was substantially different. The laboratory's role was to stimulate innovation in engine design. There was no legal mechanism to facilitate the transfer of technology generated through government research to industry. Exactly how the ideas in a NACA report took concrete form in the design of an engine could never be determined. It was part of the unwritten rules of this interaction that the government did not ask for credit or receive patents. No engine company liked to admit that innovation did not come from within its own laboratories or from the shop floor.

In the early post-World War II period, the engine industry was fearful that the NACA would interfere in the development of engine prototypes. In 1946 and 1947 the Industry Consulting Committee, composed of aircraft and engine manufacturers, criticized the laboratory's research plans for not being fundamental enough. Oscar Schey remarked that the manufacturers did not object to the NACA's research in principle, but there was no agreement over what exactly constituted fundamental research. Industry defined fundamental research as "anything that can be done with a pencil and slide rule and such facilities as the industry does not have."1 If research were limited to the more theoretical aspects of the aircraft engine-problems solved with pencil and slide rule-the laboratory might be accused of duplicating the work of the universities. 2 The laboratory valued its intermediate position between industry and academia. The heart of its work was to prod industry to innovate, but it had to avoid being used by industry to clean up immediate development problems. At the same time, it could not allow its research to become so advanced that it was of no practical use. The balance was never easy.

Although testing engine prototypes could be construed as development, it seemed essential to the laboratory's mission. The laboratory could only promote innovation if it had a thorough knowledge of existing engines. Through testing in the Altitude Wind Tunnel and later in the "four burner" area, engineers learned the mysteries of all types and makes of gas turbine engines. The machine itself was a teacher, and expertise came, in Bruce Lundin's view, from "running engines. " Lundin, who graduated from the University of California in 1942 with an engineering degree, reflected, "The reason you have the expertise is that you learn in the facilities. You don't get your expertise by a slide rule or running a computer... You get your expertise by working with real hardware and real conditions."3




The Industry Consulting Committee and members of the NACA Executive Committee at the Cleveland laboratory, September 26, 1945. Vannevar Bush is second from left.

The Industry Consulting Committee and members of the NACA Executive Committee at the Cleveland laboratory, September 26, 1945. Vannevar Bush is second from left.



Although testing isolated components like cylinders in the piston engine could provide data to predict engine performance, the jet engine as a dynamic system was far more complex. It required full-scale testing, in either a wind tunnel or a special propulsion systems laboratory. Although the jet engine's components - the compressor, combustor, and turbine - were also tested in special "rigs," some problems were apparent only when the entire system was "bolted together." On the importance of the systems approach, one engineer reflected:


An engine constitutes a dynamic system and how it reacts and behaves to external and internal changes and disturbances is of vital significance to safe flight. For example, too rapid a throttle advance can cause a compressor to go into "stall" and trigger a "surge" in the engine system. This can result in physical damage and/or combustor flame-out. How and why such phenomena occur and developing analytical means to describe and predict such events from component data are legitimate research objectives. The theories that are developed can only be verified by running a variety of systems at full scale over a range of flight conditions.4


One of the goals of basic research in gas turbine engines was to isolate and define problems common to them all. This required knowledge of all types of existing engines. In the early post-World War II years, the engine companies had no choice but to allow the Cleveland laboratory to test their engines; neither the military nor the engine companies had adequate engine facilities. They had to rely on the NACA to test military engine prototypes. Through an understanding with the military services, after the completion of a particular company's test program, the laboratory kept the engine for an additional six months. The engine was completely disassembled by [129] machine shop technicians so that the engineers could study its components and run tests. At the end of six months, Cleveland engineers knew the engine's strengths and weaknesses as well as, or better, than its original designers.

NACA engineers welcomed the increased interaction with industry brought about by this testing program. The new relationship with the engine industry had begun with the reform of the Power Plants Committee in 1940, when the engine companies won representation. Ben Pinkel, who represented the NACA on many of the subcommittees during the war and early postwar period, recalled this reform as a positive step in the creation of an effective relationship with industry. "We worked in the dark down at Langley. We did what we thought was good, but we weren't sure. " There was no system for getting information about the kinds of problems industry needed solved. Contact between engine manufacturers and NACA engineers was limited to a yearly conference. "After each talk, we would ask them, 'Well, what are your problems?' The engine company people would not talk in front of an audience that contained its competitors." Although representatives of the airframe manufacturers made many follow-up visits to Langley to communicate their requirements confidentially, the engine manufacturers remained secretive. Power Plants engineers at Langley were never able to duplicate the productive working relationship between the NACA and the airframe industry. It took the new committee structure, created by George Mead, to foster the development of trust between the proprietary engine industry and government researchers. In Ben Pinkel's view, service on various NACA committees "allowed us to get an insight, a very intimate insight" into the problems of the engine companies and the military. Government and industry engineers formed strong working relationships. For the first time, when information or a piece of equipment was needed, a phone call could bring immediate results. "The idea of this personal contact, of knowing the people in the field," Pinkel recalled, "I don't know if everybody appreciated that, but it was great."5

Although the results of research were published by the NACA, industry engine designers had no obligation to use the knowledge made available to them. More than the availability of advanced research was necessary to encourage innovation, which was costly, and the potential benefit of a small change had to be weighed against problems that it might cause in other parts of the complex engine system. To become an instrument in the transfer of advanced engine technology to industry, Lewis Laboratory had to create a market for its expertise through the building of a network of personal contacts with the growing and highly competitive industry.




Theodore von Karman, often critical of the NACA, aptly called it "skeptical, conservative, and reticent."6 von Karman could speak with the relative freedom of the academician; he could never appreciate the constraints placed on the government researcher. The practice of restricting the flow of information from the NACA originated at Langley in the 1930s through the efforts of the NACA's fastidious Executive Secretary, John Victory. All correspondence was reviewed at the branch level and signed by the engineer-in-charge. Incoming mail went first to the engineer-in-charge, and phone calls were strictly monitored. Although national security considerations may have influenced the retention of these practices after World War II, it is most likely that they originated from the need to protect secret or proprietary information. Given the traditional near-phobic concern of the engine industry about proprietary matters, NACA engineers had to be extremely careful about what information they shared with the aeronautical community outside [130] the laboratory. A loose tongue might reveal an innovation painstakingly developed by one company to its competitor.

This need for reticence, however, presented the NACA with a dilemma. The purpose of the laboratory was to encourage innovation and to stimulate competition among the engine companies by making information freely available to its entire constituency. Industry allowed publication of certain basic research, but new knowledge that could be used to make a profit was considered proprietary, the property of the company. Innovations made by industry scientists and engineers were either protected by patents or kept secret or proprietary to prevent competitors from reaping the fruits of the arduous and expensive development.7 It became apparent that, to preserve its relationships with the engine industry, Lewis Laboratory had to be willing to protect the proprietary interests of individual companies by respecting limitations on the free publication of its research.

In the testing of full-scale engines, the Cleveland laboratory ran into the teeth of the proprietary rights issue. The laboratory existed to promote competition among the engine companies, not to become a competitor itself. The government was not supposed to participate directly in development; its role was to provide basic research to support the development of engines by private industry. In practice, as long as the laboratory had facilities superior to those of the engine companies, its work could legitimately shade off into development. Industry needed the NACA to test its engines and was willing to listen to suggestions for their improvement. However, since the engine companies were in the process of building their own facilities, this aspect of its work might be curtailed in the near future. Without early access to state of the art engines, the laboratory was in danger of losing its place on the cutting edge of propulsion research.

Carlton Kemper, Executive Engineer of Lewis Laboratory, expressed this dilemma in a memo to Headquarters, November 1, 1946: "It is realized that fundamental research can be conducted on obsolete and obsolescent models of a given aircraft powerplant, but interest is always at a low ebb unless results are presented for the latest aircraft-engine models."8 He suggested that the laboratory should "cooperate wholeheartedly with these manufacturers" and that part of a successful relationship would depend on working out a mutually satisfactory policy on proprietary rights. Only this would ensure a continuing supply of engines in the development stage. General Electric, stung by the Army Air Forces award of the production contracts for the I-40 and the TG-180 engines to the Allison Company, was the first to voice its concerns to the NACA. The company admitted that Allison could produce engines more cheaply because of its government-owned factories. Nevertheless, General Electric was determined that in the future "engineering knowledge will not be turned over to a competitor at no cost, as was done in this case."9 Kemper warned that General Electric's productive relationship with the laboratory was in jeopardy unless a satisfactory solution to the problem of proprietary rights could be found. Specifically, Kemper reported, General Electric did not object to the release of wind tunnel data as long as the laboratory refrained from discussing how improved efficiencies in the turbine or compressor, for example, were obtained. "Since the war is over and they are now in a highly competitive field, they request that the Committee refrain from releasing their engineering designs to their competitors."

Kemper revealed that General Electric's decision to stay in the aircraft engine business would mean "real competition" for Wright Aeronautical, Pratt & Whitney, and the Allison Division of General Motors. That was all to the good. The more players in the engine business, the more likely they were to feel pressure to innovate, In Kemper's view, General Electric had [131] wisely decided to concentrate on development of new designs and would not invest in production facilities. Rather, it planned to subcontract with other companies for the manufacture of its new engines.

This strategy by General Electric had implications for the future research role of the laboratory. Kemper stressed that, with its new policy, General Electric would be all the more insistent that the laboratory concentrate on fundamental problems in jet engines, particularly the improvement of specific components,


To maintain our position in the research field we must concentrate on the fundamental problems of the compressor and turbine, on the design of NACA combustion chambers that incorporate the fundamental information gained by the Committee on combustion, controls, metallurgy, operating cycles, and on methods of designing more efficient compressors and turbines. It is only by having better ideas than industry that we can maintain our outstanding position in the jet-engine field.10


Despite Kemper's warning, a collision course over the proprietary rights issue had already been set. The NACA came into conflict, not with General Electric, but with Pratt & Whitney, when the company took its first step in the new field of jet propulsion. An article in Flight Magazine in spring 1946 first called attention to the superiority of the British Nene to General Electric's I-40. From the same design in less time and with inferior facilities for testing, Rolls Royce had produced a superior engine. Development of the Nene, initially ten months behind that of the I-40, had continued after World War II.11

Exactly what precipitated the Navy's interest in the Nene is unclear, but it may be related to the problems that Westinghouse was encountering in the development of the 19XB and the 24C, its turbojet with. an axial-flow compressor. Toward the end of 1946, the Navy Bureau of Aeronautics had obtained two Nene engines and tested them at the Navy's engine laboratory near Philadelphia, Penn. In a hurry to develop the Nene, the Navy invited Pratt & Whitney to tackle the job, betting on the company's solid engineering reputation to carry it off despite limited experience with turbojet engines.12 Interservice rivalry may have played a role in this decision. With the Army Air Forces committed to the I-40, the Nene represented an opportunity to upstage the Navy's rival. However, satisfaction in having a superior engine was no doubt tempered by the sobering knowledge that Great Britain, as a goodwill gesture under a Labor Government, had allowed Rolls Royce to sell the license to the Nene to the Soviet Union in 1946.13 A superior engine in the hands of a potential enemy made the production of the Nene a high national priority.

Prior to its purchase of the license to manufacture the Nene from Rolls Royce, Pratt & Whitney lacked experience in the new jet propulsion technology. The company realized that the new companies in the aircraft engine field General Electric and Westinghouse - had the advantage of a head start. Pratt & Whitney's strategy was to leap frog over its competition, building on the solid engine expertise of the British. However, from a national security point of view, the setting up of Pratt & Whitney in the production of a foreign engine had a negative side. Would the superiority of the Nene, produced by a strong and experienced engine company, squeeze out the fledgling aircraft engine efforts of Westinghouse and General Electric?

The same recognition of the superiority of British gas turbine engines that made American companies eager to obtain licenses for their manufacture made Cleveland engineers anxious to test all types of British turbojet and turboprop engines. They needed experience. They knew the strengths and weaknesses of American prototypes and were in an ideal position to point out what [132] made British engines superior. Testing the Nene seemed particularly desirable. In December 1946 Carlton Kemper wrote to the Washington office, "Such a study should be particularly valuable in that the Nene engine is reported to have higher thrust, lower specific weight, and lower fuel consumption than current American service engines.14 Exactly why the NACA was unable to obtain the Nene directly from the Navy is unclear, but the NACA took the unusual step of purchasing an engine directly from the Taylor Turbine Corporation, which owned the American license prior to its sale to Pratt & Whitney.

The Army Air Forces stood behind the NACA's decision to test the Nene and to disseminate the results to all the companies that manufactured gas turbine engines. In the view of Colonel H. Z. Bogert, the Army Liaison Officer at the Cleveland laboratory, to limit the distribution of research results hindered the ability of the United States to compete with the British. With the Nene also in the hands of the Soviet Union, the issue went beyond protecting commercial rights to issues of national security. However, even within the Army, there was no consensus on the correct policy to follow. Should distribution be limited to the five companies already involved in turbojet engine development? The civilian engineers employed at Wright Field argued that the government did not have the right to violate the proprietary rights of individual companies, since the Army paid only about 15 percent of the expenses for research and development. Kemper, however, took Bogert's side and argued for a wide distribution of research results. He thought that "it was poor policy to spend large sums in operating the Altitude Wind Tunnel and then to make the pertinent information available to only five companies because of the proprietary information in the report.15

After Pratt & Whitney began negotiations in April 1947 to acquire manufacturing and sales rights to the Nene, it became concerned over what role the NACA would play in allowing competitors to share the results of the NACA study. In December, with the acquisition of the license from Taylor Turbine complete, Pratt & Whitney informed the NACA that they held exclusive rights to the Nene and Derwent series of turbojet engines. They were, as of that date, actively engaged in production for the Navy, and the engines were therefore "in the same competition category as other Pratt & Whitney Aircraft engines." They did not object to the testing of the engine, but requested that the results be kept entirely confidential.16

There was no question that, with a good jet engine, Pratt & Whitney would be able to compete very effectively against Westinghouse, General Electric, and Allison without the help of the NACA. Moreover, with a projected date of 1950 for the completion of its Wilgoos Turbine Laboratory in West Hartford, Conn., Pratt & Whitney would soon have facilities for testing comparable to those of the Cleveland laboratory. The debate over the Nene would have important implications for any future relationship that the laboratory might develop with Pratt & Whitney and the rest of the engine industry.

In May 1948 Cleveland engineers completed the preliminary report of the tests of the Nene in the laboratory's new Altitude Chamber, designed, by Ben Pinkel. Located in the "four burner area" of the West Wing of the Engine Research Building, these "burner rigs" were the forerunners of the Propulsion Systems Laboratory completed in 1952. The NACA sent the report to Pratt & Whitney, Rolls Royce, and the military services. At the same time it expressed the desire to make the report available to other American manufacturers "who may need this research information to facilitate fulfillment of military contracts."17

Perhaps anticipating a problem with Pratt & Whitney over the distribution of the report, Hugh Dryden, Director of the NACA, brought up the general issue of reports involving specific....



Cutaway view of the Nene engine.

Cutaway view of the Nene engine.



....engines in a meeting of the Power Plants Committee in May 1948. Dryden pointed out that the NACA did not want to undermine the "competitive free enterprise system," but "it was necessary to reconcile the interests of the military services, the engine manufacturer involved, and the engineering profession, which is interested in establishing a general body of knowledge on aircraft engine research."18 Besides, Dryden pointed out, Pratt & Whitney had never objected to receiving reports summarizing the performance of the engines of its competitors, namely, Allison, General Electric, Packard, and Westinghouse.19

Pratt & Whitney's response was an unequivocal, if not unexpected, no. W, P. Gwinn, the General Manager of the company, responded, "From our point of view the information ceases to be confidential once it is given to competitive firms, either directly or indirectly. While an excellent report, in our judgment, it does not contain research information."20 Research information, in Pratt & Whitney's view, should be more general. Pratt & Whitney objected to the report's careful record of data relating to performance and design characteristics.

Pratt & Whitney's commercial interest in the engine could not be protected. The Nene in the hands of the Soviet Union made it imperative that American engines surpass the standard it had set. Because of the Nene's challenge to the American jet engine community, it became known as the "Needle engine."21 The role of the Cleveland laboratory was analogous. Its research became a prod or needle that kept industry from returning to its prewar path of extremely conservative (if profitable, in the short term) engine production.

The urgent need for a policy statement on the "release of information on specific engines" was brought up in December in the meeting of the Power Plants Committee, where it was debated at length. Dryden pointed out that "it would be uneconomical for the NACA Lewis Flight Propulsion Laboratory to construct engines for conducting research in comparison with obtaining engines built by the engine manufacturers." In general, specific engines were "supplied by the [134] military services for research requested by them. In just one case the NACA purchased the engine." He warned that if the NACA were forced to provide its own engines with public funds, it would consider itself responsible to the industry as a whole. In other words, results of testing would be published freely, and proprietary rights would not be protected. With the present system, it was only after a certain time lapse that design improvements made by a particular company were disclosed to other manufacturers, While the total number of reports involved was relatively small, Dryden admitted that a policy that would provide a satisfactory definition of proprietary information was necessary.22

The question of why Lewis Laboratory had to test specific engines at all, although not actually raised, was pertinent. Why did the laboratory appear to go out of its way to engage in work so close to development? If the laboratory was doing fundamental research, why should it test the engine prototypes of a particular company? There were two reasons: first, the laboratory performed a service to the Air Force by testing aircraft engines prior to their purchase; second, in a field that was changing so rapidly, without experience with actual engines, Lewis engineers could not be sure that their work would be relevant to the engine problems that needed urgent solution. The development of the gas turbine engine was directly related to the security of the nation. Competition could not be protected if it meant that in the event of a war the United States might have to rely on inferior engines. As one of the military members of the Power Plants Committee stated during the debate over the Nene, "One problem from the Government point of view...



Four burner area in the Engine Research Building.

Four burner area in the Engine Research Building.



[135] ....was how desirable improvements which are known to the Government can be made in engines being purchased by the Government."23

The problem with an open market system at a time of heightened concern over national security was the conflict between national interest and what would be most beneficial to the individual companies. The NACA Power Plants Committee itself was a reflection in microcosm of this larger problem. As the minutes of the meeting in which these issues were discussed reported, "The Power Plants Committee is responsible to the nation as a whole, while the members of the committee from industry are responsible to the stockholders of their companies." Proprietary rights were necessary to preserve competition, but "the question is how much compromise there should be in the best interest of the country."24

The debate revealed that, in general, there appeared to be two classes of information whose release industry found objectionable. The first type involved defects and limitations of a particular engine that could be used to damage the reputation of a company. The second type could involve, for example, a superior component like a combustor. Pratt & Whitney's representative, Leonard S. Hobbs, observed, "A man is not improved by turning over to him what a good man did." With enough information a competitor could deduce what made the combustor superior and make similar improvements. The innovating company could lose the fruits of its investment in development. In response to Hobbs's objection, Massachusetts Institute of Technology (MIT) Professor Edward S. Taylor pointed out that improved performance "is an excellent stimulus to everyone else to obtain similar improvements:' Edward P. Warner, former chief scientist at Langley, later professor at MIT and editor of Aviation, lent his prestige to the government side of the argument: "Everyone recognizes the desirability of releasing information that stimulates the other man to do as well."25

Although Lewis Laboratory won the privilege to distribute its report on the Nene because the engine was purchased prior to Pratt & Whitney's license, the policy hammered out in debates in the Power Plants Committee, the NACA Executive Committee, and the Industry Consulting Committee restricted a wide range of information from open dissemination. The policy approved in June 1949 stated that, to preserve a manufacturer's competitive position, technical information on models or components under active development would be withheld unless a specific agreement were reached with the manufacturer, Information on production models could only be furnished after review by the manufacturer. In addition, the manufacturer was to be furnished with the list of companies and individuals to whom the NACA intended to send information. Finally, any oral communication by the NACA before a report was issued was subject to review.

This strict policy on proprietary rights prevented free dissemination of knowledge gleaned at government expense. However, the NACA could not refuse to agree to it. Without a satisfactory relationship with industry, the Cleveland laboratory would lose its central position in the mainstream of jet engine development. The cardinal rule of the laboratory became discretion. When representatives of engine companies arrived to follow the tests on a particular engine built by their company, their movements on the laboratory grounds were strictly limited to prevent them from obtaining information about an engine of a competitor undergoing tests at the same time. The staff learned to choose their words carefully. They mastered the elaborate choreography of "who gets what information." This discreet behavior of NACA engineers contributed to the growing respect for the laboratory on the part of the engine companies. However, the NACA paid a price. Capitulation to the engine companies kept the NACA in the mainstream of engine [136] development, but it limited the information the NACA could publish freely to the entire industry. Its role as a goad to promote innovation by stimulating competition was compromised.

The unfavorable outcome of the debate over proprietary rights reveals the vulnerability of the NACA as the tensions of the Cold War increased. Although military planners looked on the USSR as a possible enemy in the event of World War III as early as 1945, this threat did not seem immediate because of the perceived inferiority of Soviet technology.26 The Nene design in Soviet hands began to change that perception. Oscar Schey, head of the Compressor and Turbine Division, pointed out in a 1948 memo that, in contrast to the engine situation in the late 1930s, when they had more than 20 years of experience in reciprocating engines, the engine community had barely four years of experience in jet technology. "As Dr. Lewis often pointed out at the beginning of World War II," he wrote, "we had to fight the war with the five engines that had already been developed and were in production. " In 1948 the United States mass produced only one turbojet engine, the Allison J-33 (General Electric's 1-40).27 Knowledge of the limitations of the General Electric 1-40 compared to the Nene heightened the concern of all knowledgeable engine experts. So great was the pressure to improve existing engines that Schey advocated an extension of the work week to 48 hours. When Congress passed the Unitary Wind Tunnel Plan Act the following year, the Air Force received funding for the Arnold Development Engineering Center in Tullahoma, Tenn. With extensive wind tunnels and other facilities for testing engines projected for Tullahoma, the facilities at the Cleveland laboratory would lose their unique value to the propulsion community. Moreover, the Act stipulated that the Unitary Plan tunnels built by the NACA were to be made available to industry for testing programs.28 The Cold War threatened to push the laboratory back into development - its wartime role of mopping up for the engine companies.




The focus on the Nene raised the question, why did the British produce superior engines when their facilities were markedly inferior to those of the United States? Not only did the United States have better facilities, but American engines were made of better alloys developed to withstand the higher temperatures of the combustor and turbine. A consensus emerged that the superiority of British engines was the result of meticulous engineering and closer cooperation between members of the propulsion community. For example, John Collins, Chief of the Engine Performance and Materials Division, believed that British superiority could be "attributed to a large extent to refinements in the details of the engine design and construction."29 Dryden was more blunt. He observed after a trip to England at the height of the proprietary rights debate that the "lack of money for facilities has forced them to make the best use of their brains."30 In addition, the British had been able to foster "a much closer collaboration between the engine companies in technical matters." Dryden called the attitude of Rolls Royce executives on the release of information, "in refreshing contrast to those of Pratt and Whitney, for example."31

Dryden's perceptions correctly reflected the more cooperative approach of British engine companies. The British Gas Collaboration Committee, established in November 1941 to spur the development of the turbojet, encouraged engineers to share information. Frank Whittle recalled that the committee "helped a lot to decide in what order things should be done." About ten groups involved in jet engine development met monthly, and, although the meetings were stuffy and formal, at the parties in the evenings, "we really found out what each other was doing."32 The rationale for the Collaboration Committee was the belief that good ideas should be made available [137] to whomever could use them. In Dryden's eyes, the difference in attitude on the part of British companies contributed to the continued superiority of British engines.

In the United States competition was regarded as the key to a healthy economy. The sharing of technical innovations was prohibited by American anti-trust laws. 33 As late as 1948, the general lack of coordination and communication among research laboratories and industry was noteworthy to P. F. Martinuzzi, an Italian gas turbine expert employed by the British. He remarked, on a trip sponsored by the American Society of Mechanical Engineers, that within the American industry "the general trend is to tackle the problems independently of past experience and of what competitors are doing." Available data were neglected by designers. The author had high regard for the research of the Cleveland laboratory, but it was hardly a clearinghouse for information. Companies engaged in development of jet engines did not pay much attention to what the NACA or any other laboratories were doing. 34

Despite the availability of NACA research, the engine companies resisted new ideas on the technological frontier. Hans von Ohain, then a research scientist at Wright Field, recalled that when they were invited to the Cleveland laboratory to hear the results of the laboratory's latest research, "it was almost a festival because they had such interesting and good things to say." The Air Force was "all ears," but the work at Lewis was so advanced that "industry fought it to the teeth."35 This was particularly true in the compressor area, where fundamental work on the transonic compressor was eventually incorporated into the design of the turbofan. Von Ohain credits Silverstein with the vision to persevere with compressor research, despite the attitudes of the engine companies.

Gradually, the research of the Cleveland laboratory won respect and assisted in the transfer of new ideas from the realm of the research report to the design of an engine. In addition to published reports, technical transfer occurred through personal contacts between government engineers and scientists and their counterparts in industry. The most effective avenues for this exchange were special conferences to which selected individuals were invited. In addition, the laboratory held triennial inspections to show off its facilities and explain the latest research. Employees who were selected to give talks at various laboratory "stops" prepared their talks carefully. NACA engineers learned to be articulate, personable, and lucid in explaining complex material. Laboratory tradition also encouraged after-hours socializing with industry representatives. Gradually Lewis engineers became valued colleagues to their counterparts in industry. For the engine designer, being, able to associate a report with a face and knowing the history of a particular piece of research through personal conversations created a general climate for acceptance.



To develop afterburners required full-scale engine testing. Here a system consisting of twin exhausts is tried on General Electric's I-40, 1949.

To develop afterburners required full-scale engine testing. Here a system consisting of twin exhausts is tried on General Electric's I-40, 1949.


[138] A mutual desire to keep abreast of what the other was doing led to a series of official British and American contacts through the late 1940s and early 1950s. A series of British missions visited the Cleveland laboratory, and representatives from the laboratory went abroad. The Army organized one of the first American postwar tours, which came to be called by the British, "The American Gas Turbine Mission." Walter T. Olson represented the Cleveland laboratory on the nearly month-long tour in June 1947, visiting the major British engine manufacturers, as well as the British government laboratories, the National Gas Turbine Establishment at Whetstone, the National Physical Laboratories at Teddington, and the Royal Aircraft Establishment at Farnborough. The tour ended with visits to American engine companies to educate them concerning the latest British advances.

The mission drew no general conclusions about the reasons for continued British superiority. Nevertheless, an example cited by Olson showed the advantage of greater coordination and the sharing of information. The development of a "universal" combustor by the Lucas Company had led to its adoption by a number of British companies, thereby saving them the trouble of repeating work that had already been done. Olson wrote:


The main advantage in combustion that England enjoys is that virtually all new gas turbine engines start off with a reasonably well developed combustor. In the United States the engines now under development have a variety of styles of combustor, many of them quite unproven. This is because in the United States there has been no one organization with the manpower, the money, and a clear mandate to develop a "universal" combustor for the industry; that is no counterpart of the Lucas Company.36


While the general superiority of British engineering, combined with a spirit of greater collaboration, could be seen in the Nene, British work on engines with axial-flow compressors, however, appeared to be behind that of General Electric's TG-180 and the various models of the Westinghouse "Yankee" engine G34/24C). In compressor, design, the strong emphasis by the NACA on the development of an axial compressor eventually allowed the United States to pull ahead of the British. Testing the Nene, in fact, contributed to the Cleveland laboratory's growing confidence that the Nene's centrifugal compressor had limitations that would soon be overcome by the more efficient axial design. Nevertheless, the British were also pushing the development of an engine with axial compressors. Rolls Royce's Avon engine was "without question the 'blue chip! project" because, Olson reported, many British aircraft companies with projects in the design stage planned to use the Avon engine. 37 The first major departure from the Whittle design, the Avon was used in the Canberra Bomber and other important British planes. It was selected for the De Haviland Comet, intended to be the world's first passenger jetliner.38

Clearly with the knowledge of the Cleveland laboratory's work on the axial compressor in mind, Olson noted, "It is quite generally appreciated among compressor research and design personnel that some theory for the effect of the boundary layers in compressors and cascades is urgently needed. Only trivial progress has been made on this problem to date."39 Great Britain was at a disadvantage because it lacked altitude chambers to test full scale engines and facilities to test components, such as compressors, at high speeds.40 The National Gas Turbine Establishment was the only organization in Great Britain conducting large-scale cascade tests over a wide range of conditions, but Olson revealed, "The cascade results are inaccurate because of boundary layer effects in the cascade test rig itself." 41




[139] Lewis Laboratory's Compressor and Turbine Division conducted research on both centrifugal and axial compressors. John Stanitz applied a relaxation solution to the problem of two-dimensional compressible flow in a centrifugal compressor with straight radial blades - an achievement that established him as an expert in centrifugal compressors.42 However, the compressor staff always had greater enthusiasm for the axial compressor - a legacy of the NACA's first eight stage axial compressor designed by Eastman Jacobs and Eugene Wasielewski in 1938 and tested in 1941. The smaller frontal area of the axial compressor made it more compact and better suited aerodynamically for flight than the more cumbersome centrifugal compressor. However, the greater aerodynamic complexity of the axial compressor presented enormous scientific and engineering challenges. An axial compressor had to be designed so that air moved smoothly across each of the rows of compressor blades. Research initiated in 1944 with the transfer from Langley of work on the Jacobs-Wasielewski eight-stage compressor laid the basis for the laboratory's future achievements in the compressor field. Jacobs and Wasielewski had approached compressor design by applying the theory for an isolated airfoil. This became the standard approach of American designers until the mid-1950s.43

Frank Whittle, for example, looked with bemused superiority at what he considered the Cleveland laboratory's misplaced emphasis on the axial compressor. On a visit to the laboratory in 1946, he asserted that the centrifugal compressor would continue to be preferred for its rugged dependability. In 1948 the abandonment of the centrifugal compressor by American designers was called a "pity" by the Italian expert P. R Martinuzzi (at that time working for the British) "because it appears that the axial compressor types which have replaced the earlier centrifugals are not more reliable, are heavier and 'several times' more expensive." Martinuzzi speculated that American emphasis on the axial compressor might reflect "a desire to disclaim British influence."44

Between 1945 and 1950 the relative merits of the centrifugal versus the axial compressor were debated in Great Britain.45 However, in the United States few engineering voices were raised in support of the centrifugal compressor. The main effort among American engineers focused in the early postwar period on developing the axial compressor. American industry designers came to rely on NACA-generated data based on the isolated airfoil approach. As Brian Nichelson pointed out in his recent Ph.D. dissertation:


It made sense for the Americans to rely on the isolated airfoil method in light of the wealth of data available from the NACA on the performance of a large family of airfoil profiles. Whereas the Germans had rejected the isolated airfoil approach because it would have required a great deal of experimental data, the Americans already had such data available, courtesy of the NACA. It also made sense in another respect: Americans had long used a blade element design technique based on airfoil theory in designing propellers and single-stage fans and blowers. As a result, American designers not only felt comfortable using this type of design theory, they also began to view the time and energy spent in developing it as an investment. Thus the isolated airfoil approach became the main American axial compressor design theory during the 1940s.46


The isolated airfoil approach was not precise enough to give accurate predictions of compressor performance. The limitations of the isolated airfoil approach were first recognized by [140] British aerodynamicists A. A. Griffith, Hayne Constant, and A. R. Howell of the Royal Aircraft Establishment (RAE). Howell published his two landmark papers on cascade theory in 1945. However, American compressor designers, reluctant to abandon old approaches and habits, ignored the British cascade method until the mid-1950S.47

It is difficult to determine exactly what role members of the Lewis Compressor Division played in initially promoting the isolated airfoil approach and later coaxing the engine manufacturers to give it up. Industry designers never liked to admit they picked up useful information from NACA reports and conferences. From the early postwar years, members of the Compressor and Turbine Division had concentrated on developing a supersonic compressor based on the work initiated by Arnold Redding at Westinghouse and Arthur Kantrowitz at Langley during World War II. British cascade studies received increased attention as this work expanded. In the area of three-dimensional flows, the research of Frank Marble, Chung-Hua Wu, and Lincoln Wolfenstein built on Howell's work and that of German researchers Walter Traupel and Richard Meyer. Marble described the flow of an ideal incompressible fluid through an axial compressor. Wu and Wolfstein tackled the problem of a compressible fluid flowing across stages of an infinite number of blades.48

In 1952 efforts at Lewis Laboratory were directed by Robert O. Bullock to the development of a transonic compressor. Bullock headed a group that included William K. Ritter, William A. Benser, Harold B. Finger, John E Klapproth, Melvin J. Hartmann, Arthur A. Medieros, Seymour Lieblein, and Irving A. Johnsen. Hartmann and others developed a flow model for estimating the shock losses that could be anticipated as the air flowed through the compressor. Seymour Lieblein developed the diffusion factor, D, now universally accepted as a measure of blade loading. Ten years of single- and multi-stage investigations culminated in the development of an experimental eight-stage axial-flow transonic compressor.49

To verify theories developed analytically, the compressor staff designed and built complicated facilities, called single- and multi-stage compressor test rigs. The data they provided were essential to industry designers. Without this verification of mathematical predictions, no engine company would have had the temerity to undertake the expensive development of a new compressor. Results, made available to the entire industry through NACA reports, became the "Compressor Bible" to members of the engine community. Eventually the Compressor Division prepared a manual that summarized the entire corpus of compressor knowledge. This manual, issued in 1956 as a three-volume NACA Confidential Research Memorandum edited by Irving Johnsen and Robert O. Bullock, marked the culmination of NACA compressor research."50

The NACA may have played a role in the development of compressors similar to that of the British Lucas Company for combustors. The laboratory concentrated on generic components for application in a variety of engines produced by different manufacturers. While....



The Jacobs-Wasielewski eight-stage axial compressor perfected in the 1950s.

The Jacobs-Wasielewski eight-stage axial compressor perfected in the 1950s.


[141].....the Lucas company actually built combustors to sell, the NACA aimed to establish a body of knowledge on which designers could depend. NACA compressor work advanced the general state of the art through dissemination of information, thereby saving individual companies the cost and time of doing this research themselves. At the same time, by making knowledge freely available to the entire engine community, it discouraged one company from locking in a competitive advantage.




For the NACA, maintenance of elaborate research facilities cut into the time that could be devoted to actual research, and, at first, the British maintained their lead in the new field of jet propulsion. As Ben Pinkel recalled, a member of a British delegation once asked him, "When do you have time to brood?" However, in the long run these facilities paid off. In the absence of superior facilities, the British government funded basic research by the engine companies that was carried on independently of the development of specific engines.51 Not only did the British differ in the way that research was funded, but also in styles of approach to the development of specific engines. The British used a cut-and-try approach that depended on building and testing successive models of a particular engine. As Ray Sharp observed on a lengthy trip to Europe in 1951:


Instead of concentrating first upon acquiring the tools, the equipment, best suited for use in investigating powerplant problems and developing more powerful engines, the....



One of the unique compressor rigs used to test axial compressors, 1948.

One of the unique compressor rigs used to test axial compressors, 1948.



[142] ....British spend great amounts of manpower and money to build large numbers of a new experimental model, each one slightly different from the other. They often come up with a very good end-product, but the cost is greater, I believe, than our system in which we first study the problems involved, using our equipment, and then go ahead and build only two or three of a new model.52


So respected was the resultant engineering from the British system that in 1953, when Westinghouse needed help with its foundering 24C turbojet engine, the company signed a mutual assistance agreement with Rolls Royce to share afterburner technology in order to benefit from British turbojet expertise. On a visit to the Cleveland laboratory after the signing of this agreement, the Rolls Royce representative confided that he had been "directed by Lord Hives to follow through on the collaboration between the two companies and see if Rolls Royce could 'make an engine company out of the bloody buggers.'"53 However, while the British approach yielded short-term benefits, by the early 1950s British domination of the aircraft engine field had begun to slide.

The key to the postwar American approach to engine development was the involvement of government engineers. The Cleveland laboratory built the necessary facilities for testing complete engine systems, but its expertise went beyond full-scale testing to the study of individual components. NACA engineers developed theories to predict engine performance and verified these theories in special "rigs." The NACA tackled specialized areas of research, such as components, combustion and fuels, lubricants and seals, materials, and heat transfer. Through publication and interaction between industry and government engineers, the laboratory encouraged innovation while saving the engine companies some of the costs of development. Government research promoted innovation. A designer could not ignore a particular innovation if it was likely that his company's competitors were going to incorporate it into their latest engine prototypes.

The Korean War (1950-1953) marked a turning point in the development of the American turbojet industry and the end of British dominance. Before the Korean War,...


A Westinghouse axial-flow turbojet fitted with NACA variable area nozzle for afterburner studies in the Altitude Wind Tunnel, 1951.

A Westinghouse axial-flow turbojet fitted with NACA variable area nozzle for afterburner studies in the Altitude Wind Tunnel, 1951.


[143] ...more than half the aircraft engines produced in the United States were of the piston engine type. By the end of the war, the balance had shifted, primarily because of the reequipment of the Navy with jet planes.54 During the war, Pratt & Whitney was the licensee for the production of the Rohs Royce Tay, or J48, the most powerful engine produced by either the United States or Great Britain. The Tay, however, was the last British engine to reflect the superiority of British engines. When Wright Aeronautical bought the license for the British Armstrong Siddeley Sapphire (designated the J-67 by the United States Air Force), a turbojet with an axial compressor, the company found that its thrust was too low for the aircraft it was intended to power. The failure of Wright's development of the Sapphire contributed to its demise.

Ironically, Pratt & Whitney, many years behind Westinghouse and General Electric in acquiring turbojet expertise, began to dominate the turbojet industry after its development of the JT3 (J57). The JT3 initially had better fuel economy and more than double the thrust of its competitors. The innovative design feature of Pratt & Whitney's engine was an axial compressor with a double shaft (also called a dual-rotor or two-spool), a feature that dramatically increased the efficiency of the compressor. This engine placed the company in the forefront of aircraft propulsion development.55 General Electric's answer to Pratt & Whitney's JT3 was the J79 with an innovative compressor with variable stators.56

By the mid-1950s the American turbojet industry had matured and narrowed to two companies: Pratt & Whitney and General Electric. British aircraft engine companies found it increasingly difficult to compete against their American counterparts. Two tragic crashes of the Comet in 1954 left the De Haviland Company in an unfavorable competitive position. The crashes were caused by metal fatigue brought on by the cyclical pressurization of the cabin, not by the aircraft's Avon engines. Before the Comet regained its Certificate of Airworthiness, De Haviland had lost the commercial market to Boeing's 707 and the Douglas DC-8, powered by Pratt & Whitney's JT3.57 The British had set the stage for the turbojet revolution, but they could not sustain their early lead.

The development of superior NACA facilities for testing engine prototypes played a role in American dominance in the engine field. This view is supported by remarks made by Rolls Royce representatives on a visit to Lewis Laboratory in 1955. They lamented that the company "has been 'led up the garden path' by the Labor and Conservative governments which have promised to provide full-scale test facilities for the British gas turbine industry since 1945."58 Since these promised facilities still had not materialized, Rolls Royce planned to spend the equivalent of $15 million to build two small wind tunnels and two altitude test chambers. In addition, in 1955 the British made plans to...



Pratt & Whitney's dual spool turbojet engine (JT3/P57) in the Altitude Wind Tunnel for nozzle studies as part of the NACA's aircraft noise suppression research, 1957.

Pratt & Whitney's dual spool turbojet engine (JT3/P57) in the Altitude Wind Tunnel for nozzle studies as part of the NACA's aircraft noise suppression research, 1957.


[144] ....build a large altitude test facility to test full-scale engines at the National Gas Turbine Establishment at Pyestock, with a second at Bedford. These facilities came too late to recoup the British lead. Rolls Royce continued to send its engines to Cleveland for testing. As late as 1956, records from the log of the Altitude Wind Tunnel indicate that the NACA tested the Rolls Royce Avon engine.

The Cold War justified the continued sharing of British engine technology with the United States - an exchange heavily weighted in favor of the United States. Lewis engineers developed an intimate knowledge of British engines they could share with Pratt & Whitney and General Electric. American engine companies received a financial boost from large defense contracts necessary because of the dominant role of the United States in the North Atlantic Treaty Organization (NATO). The early 1950s also marked a decline in the influence of Lewis Laboratory in the aircraft engine field. The military services and industry had begun to develop facilities comparable or superior to those of the laboratory. The era of the air-breathing engine research at Lewis seemed to be reaching a natural point of termination. It was time to reassess Lewis's future role in the nation's propulsion research.





1. Memo from Oscar Schey to the Washington office, "Survey of Fundamental Research of the NACA-Aircraft Industries Association Comments," 19 November 1946, NASA Lewis Records, 34/376. See also Minutes of the Industry Consulting Committee, 3 December 1947, Committees and Subcommittees, National Archives, Record Group 255.

2. Memo for the Chief of Research from Eugene Manganiello, 25 February 1946, NASA Lewis Records, 34/624.

3. Interview with Bruce Lundin, 15 July 1986. Also interview with Carl Schueller, 12 October 1984.

4. Seymour C. Himmel, personal communication.

5. Transcribed interview with Ben Pinkel, 3 August 1985, p. 17.

6. Quoted by Walter A. McDougall,(the Heavens and the Earth (New York: Basic Books, 19851, p. 164.

7. See George Wise, Willis R. Whitney, General Electric, and the Origins of US Industrial Research (New York: Columbia University Press, 1985), p. 106.

8. Memo from Carlton Kemper to NACA, 1 November 1946, NASA Lewis Records, 34/317.7.

9. Memo from Carlton Kemper to Director of Research, "Visit to General Electric River Works, Lynn, Mass., with Colonel Bogert to Discuss Their Objections to the Method of Handling Proprietary Material in NACA Reports," 3 February 1947, NASA Lewis Records, 341317.76.

10. Ibid.

11. Flight, 18 April 1946, p. 389-93. Note: Because at the time the Nene was developed, the British had no suitable airframe, the Rolls Royce Company built a scaled-down version, the Derwent series of engines, to power the Meteor, one of the few airplanes able to fly fast enough during World War II to shoot down the V-1. Development of the Nene was actually started ten months after the 1-40, but, unlike General Electric, which stopped development at the end of the war, Rolls Royce engineers continued to perfect the Nene. See Robert Schlaifer, The Development of Aircraft Engines (Boston: Graduate School of Business Administration, Harvard University, 1950), p. 373 and 476.

12. The Pratt & Whitney Aircraft Story (West Hartford: Pratt & Whitney Aircraft Division of United Aircraft Corporation, 1950), p. 168.

13. Sir Stanley Hooker stated in Not Much of an Engineer (Shrewsbury, England: Airlife, 1984), p. 98, "With Sir Stafford Cripps at the Board of Trade, the left-wing British Government appeared perfectly happy to sell our latest engine to the Russians, and in September 1946 clinched a deal for 25 Nenes and 30 Derwents, the first few of which the team took back to the Soviet Union and copied exactly in double-quick time. They were produced in colossal numbers for the MiG-15 and -17, 11-28, Tu-14 and many other aircraft. These aircraft were also supplied to the Soviet satellite countries, and North Korea! Over 20 years later I saw VK-1s (Soviet Nenes) being overhauled in Romania!' For a discussion of British labor policy, see also Keith Hayward, Government and British Civil Aerospace (Manchester: Manchester University Press, 1983), p. 12 27.

14. Carlton Kemper to NACA, "Investigation of Rolls Royce Nene jet propulsion engine:' 9 December 1946, NASA Lewis Records, 34/623.

15. Carlton Kemper, "Conference Called by Colonel Bogert at Wright Field, January 23, 1947, Regarding Proprietary Material in NACA Reports for the Army Air Forces," NASA Lewis Records, 34/317.7.

16. W. P. Gwinn to NACA, 3 December 1947, Power Plants Committee, National Archives, Record Group 255, 41112.05.

17. Zelmar Barson and H. a Wilsted, "Preliminary Results of Nene II Engine Altitude-Chamber Performance Investigation, I-Altitude Performance Using Standard 18.75-Inch-Diameter jet Nozzle," NACA Research Memorandum E8EI2, 25 May 1948. J. W. Crowley to L. S. Hobbs, 25 May 1948, National Archives, Record Group 255, 41112.05.

18. Power Plants Committee Minutes, 21 May 1948, National Archives, Record Group 255, 112.02, p. 9.

19. Hugh L. Dryden to W, R Gwinn, 2 August 1948, National Archives, Record Group 255, 4/112.05.

20. W. P. Gwinn to J. W, Crowley, 9 July 1948, National Archives, Record Group 255, 4/112.05.

21. Pratt & Whitney Aircraft Story (West Hartford: Pratt & Whitney Aircraft Division of United Aircraft Corporation, 1950), p. 168.

22. Power Plants Committee Minutes, 10 December 1948, National Archives, Record Group 255, 112.02, p. 13.

23. Power Plants Committee Minutes, 10 December 1948, National Archives, Record Group 255, 112.02, p. 11.

24. Ibid.

25. Ibid, p. 12.

26. Michael S. Sherry, Preparing for the Next War (New Haven: Yale University Press, 1977), p. 169-219.

27. Oscar Schey, "Memorandum for the Director," 11 March 1948, NASA Lewis Records, 34/376.

28. Alex Roland, Model Research, vol. 1, NASA SP-4103 (Washington, D.C.: U.S. Government Printing Office, 1985) p. 215-219.

29. John Collins to Director of Aeronautical Research, 29 January 1947, NASA Lewis Records, 34/376.

30. Minutes of the NACA Executive Committee, 9 September 1948, National Archives, Record Group 255, 14/112.05.

31. Hugh L. Dryden to John Victory, 29 August 1948, NASA Lewis Records, 232/150.

32. An Encounter Between the Jet Engine Inventors, History Office, Aeronautical Systems Division Air Force Systems Command, Wright-Patterson Air Force Base, Historical Publication, 1978, p. 97.

33. Abe Silverstein's comment to the author, September 1986.

34. P. R Martinuzzi, "Gas Turbines in the United States," Flight, 7 October 1948, p. 439-441.

35. Interview with Hans von Ohain by V. Dawson, 11 February 1985, National Air and Space Museum, Washington, D.C.

36. Walter T Olson to Executive Engineer, "Tour of Aircraft Gas Turbine Industry in England," 22 August 1947, NASA Lewis Records, 34/621.

37. Ibid.

38. See Michael Donne, Leader of the Skies, Rolls-Royce: The First Seventy-five Years (London: Frederick Muller Limited, 1981), p. 68; Keith Hayward, Government and British Civil Aerospace: A Case Study in Post-War Technology Policy (Manchester: Manchester University Press, 1983), p. 19-22.

39. Walter T. Olson, "Tour of Aircraft Gas Turbine Industry in England," p. 5.

40. Ibid, p. 87-88.

41. Ibid, p. 4.

42. See John D. Stanitz, "Two-Dimensional Compressible Flow in Conical Mixed Flow Compressors," NACA TN 1744, 1948.

43. Brian J. Nichelson, "Early jet Engines and the Transition from Centrifugal to Axial Compressors: A Case Study in Technological Change," Ph.D. Dissertation, University of Minnesota, 1988, p. 115. John T. Sinnette, Jr., Oscar W. Schey, and J. Austin King, "Performance of NACA Eight-Stage Axial-Flow Compressor Designed on the Basis of Airfoil Theory," NACA TR 758, 1943. This report was first published as NACA Wartime Report E4H18 in August 1944. NACA TR 758 was actually published in 1945. John T. Sinnette, Jr., and William J. Voss, "Extension of Useful Operating Range of Axial-flow Compressors by Use of Adjustable Stator Blades:' NACA TR 915, 1948. It seems likely that NACA data on the use of variable stator compressor blades contributed to the design (begun in 1951) of General Electric's enormously successful J79.

44. P R Martinuzzi, "Gas Turbines in the United States," Fight, 7 October 1948, p. 439. Frank Whittle's comment was reported in an interview with the author by John Sanders, 6 April 1985. The Whittle visit is described in Wing Tips, 19 July 1946, NASA Lewis Technical Library.

45. Brian Nichelson, "Early Jet Engines," p. 162-208.

46. Ibid, p. 115-116.

47. Ibid, p. 153. See also R F. Martinuzzi, "Continental and American Gas-Turbine and Compressor Calculation Methods Compared:' Transactions of the American Society of Mechanical Engineers 71:325-333. 1 am indebted to Captain Brian Nichelson for this reference and for his insight into the differing British and American approaches. Silverstein appears to have advocated the isolated airfoil approach as late as 1949 in the Twelfth Wright Brothers Lecture, "Research on Aircraft Propulsion Systems!' journal of the Aeronautical Sciences 16:197-226.

48. Chung-Hua Wu and Lincoln Wolfenstein, "Application of Radial Equilibrium Condition to Axial-Flow Compressors and Turbines Design," NACA TN 1795, 1949.

49. For a summary of this work, see Seymour Lieblein and Irving A. Johnsen, "Resume of Transonic-Compressor Research at NACA Lewis Laboratory." Transactions of the ASME Journal of Engineering for Power, offprint 60-WA-97, 1960.

50. Members of the Compressor and Turbine Research Division, "Aerodynamic Design of Axial Flow Compressors," vol. 1-3, NACA RM E56B03, E56B03a, E56B03b, 1956. A revised declassified edition was published as Aerodynamic Design of Axial-Flow Compressors, NASA SP-36, 1965. Reference to the "Compressor Bible" was made in an informal talk with the author by Marvin A. Stibich, Aero Propulsion Laboratory, Wright-Patterson Air Force Base, Dayton, Ohio. The division disbanded in 1957, when the laboratory shifted into nuclear and space-related projects. It was brought back to life in the late 1960s, when the laboratory returned to aeronautics work.

51. Hugh L. Dryden to John Victory, 29 August 1948, NASA Lewis Records, 34/300.

52. Interview with Sharp and J. J. Haggerty American Aviation Magazine, December 1951, and E. R. Sharp biography file, NASA History Office, Washington, D.C.

53. John H. Collins, Jr., "Visit of Messrs. L. Dawson of Rolls Royce, Ltd. and R. P. Kroon, V. V. Schloesser, and M. Norton of Westinghouse Electric Corporation, on June 5, 1953:' NASA Lewis Records,'232/150.

54. Charles D. Bright, The Jet Makers. The Aerospace Industry from 1945 to 1972 (Lawrence, Kansas: The Regents Press of Kansas, 1978), p. 15.

55 In 1952 Pratt & Whitney received a Collier Trophy for the JT3, the first award for a power plant in 21 years. See booklet, "Presentation of 1972 Elmer A. Sperry Award to Leonard S. Hobbs and Perry W. Pratt," AIAA Ninth Annual Meeting, Courtesy of United Technology Archives, East Hartford, Conn. The dual-spool concept may originally have been British.

56. Development of General Electric's J79, headed by Gerhard Neumann, began in 1951. It was flight tested in 1955. See Seven Decades of Progress: A Heritage of Aircraft Turbine Technology (Fallbrook, Calif.: Aero Publishers, 1979), p. 84-91.

57. Keith Hayward, Government and British Civil Aerospace: A Case Study in Post-War Technology Policy (Manchester: Manchester University Press, 1983), explores some of these issues, although his discussion of the aircraft engine industry is limited.

58. Carlton Kemper, "Visit of Personnel from Rolls Royce Ltd. England to Lewis on January 10 and 11, 1955, 19 January 1955, NASA Lewis Records, 232/150.