Chapter 2


To many NACA engineers, the agency's first fifteen years represented remarkable aeronautical progress. The next fifteen years, from 1930 to 1945, seemed even more remarkable, as streamlined aircraft became commonplace, World War II spawned an impressive variety of modern combat planes, and rocketry became an awesome force in twentieth century warfare.

The propeller research tunnel at Langley continued to yield significant information that resulted in equally significant design refinements in the new generation of airplanes. One of the most obvious had to do with fixed landing gear. As a means to increase speed, retractable landing gear was not unknown, since this approach had been tried on various airplanes before and after World War I. But retractable gear required additional equipment for raising and lowering and appeared to lack the ruggedness and reliability of conventional, fixed gear. On the other hand, fixed gear was thought to be a major drag factor, although nobody had accurately assessed the aerodynamic liability. NACA engineers set up a series of tests using the propeller research tunnel to get an accurate measure of the fixed gear's drag on a Sperry Messenger. The results were astonishing. Fixed gear was estimated to create nearly 40 percent of the total drag acting on the plane. This eye-opening news, a dramatic demonstration of the performance penalty incurred by fixed gear, prompted rapid development of retractable gear for a wide variety of airplanes. The NACA's tests played a large role in the evolution of modern, retractable-geared aircraft.

There were further projects that pointed the way to sleeker airplanes emerging by the end of the 1930s. Trimotored airliners, like the Fokkers, Fords, and Boeings, had become standard equipment in America and elsewhere during the late 1920s. They could not easily be redesigned to mount retractable gear, but the trio of big, blunt radial engines that powered them could be shrouded with the new NACA cowling to give them much improved performance. Engineers at Langley took a Fokker trimotor powered by three Wright J-5 Whirlwind engines and fitted it with cowlings. Confident expectations of sudden enhancement of performance were dashed and engineers were baffled. They began to wonder if the installation of engines had something to do with it. So as not to encumber the wing, the original designers had placed the engines on struts beneath the wing (or, in the case of biplanes like the Boeing 80, between the wings). After getting the big Fokker set up in the propeller research tunnel, Langley engineers ran a series of tests that conclusively changed the looks of multiengine transports to come. They discovered that the best position for the engines was neither above or below the wing, but mounted as part of its structure--situated ahead of the wing, with the engine nacelle faired into the wing's leading edge.

This was the sort of information that also contributed to the evolution of the modern airliners of the decade. Conventional wisdom in the past had dictated that wings should be mounted high on the fuselage, permitting engines to be slung underneath with clearance for the propeller arc. This meant complex struts (creating drag) and led to the use of awkward, long-legged fixed gear (creating even more drag). By mounting engines in the wing's leading edge, the wing could be positioned on the lower part of the fuselage, which meant that the landing gear was now short-legged and less awkward--in fact, retractable. Influenced by NACA research, low- winged monoplanes with retractable gear soon replaced the high-winged design for airliners and many other aircraft.

The propeller research tunnel at Langley had obviously been a profitable facility, although it had limitations for thorough testing of full-sized aircraft. In 1931, when the full scale tunnel was officially dedicated, Langley engineers used it to launch a new round of evaluations which, while sometimes less dramatic than cowlings, unquestionably added new dimensions to the science of aerodynamics. Its impressive statistics marked the beginning of test facilities of heroic proportions.

Nonetheless, the full scale tunnel did not overshadow other Langley test facilities. There were those who felt that the shortcomings of the variable density tunnel, with its acknowledged drawbacks in turbulence, would soon be eclipsed by the huge full scale tunnel. With partisans on both sides, friction between personnel from the variable density tunnel and the full scale tunnel became legendary. In time, both established a relevant niche in the scheme of things. Meanwhile, the variable density tunnel played a key role in many projects, and its personnel made a singular contribution to the theory of the laminar flow wing.

While the variable density tunnel could test many more varieties of aircraft designs, which could be built as scale models, the turbulence issue continued to dog research findings. In the process of studying this issue, researchers took a closer look at flow phenomena, especially the "boundary layer," where so many problems seemed to crop up. The boundary layer was known to be a thin structure of air only a few thousandths of an inch from the contour of the airfoil. Within it, air particles changed from a smooth laminar flow from the leading edge to a more turbulent state towards the trailing edge. In the process, drag increased. After observing tests in a smoke tunnel and evaluating other data, aerodynamicists concluded that the prime culprits in disrupting laminar flow were traceable to the wing's surface (rivet heads and other rough areas) and to pressure distribution over the wing's surface.

full size biplane is mounted infront of a wind tunnel for testing
A Vought O3U set up for tests using the full scale wind tunnel at Langley, completed in 1931.

Eastman Jacobs, head of the variable density tunnel section, came up with various formulas to allow for the tunnel's turbulence in evaluating models and pushed for a larger, improved tunnel. He also championed a systematic experimental approach in airfoil development.

Jacobs was often challenged by a Norwegian emigre, Theodor Theodorsen, of the Physical Research Division. Theodorsen, steeped in mathematical research, was a strong proponent of airfoil investigation by theoretical study. His opposition to Jacobs's proposal for an improved variable density tunnel and his insistence that, instead, Langley personnel needed more mathematical skills and theoretical concepts, sharpened the debate between experimentalists and theorists within the NACA. Jacobs, in fact, kept abreast of current theories, and he eventually fashioned a theoretical approach, backed up by his trademark experimental style that led to advanced laminar flow airfoils.

While the NACA deserves credit for its eventual breakthrough in laminar flow wings, the resolution of the issue illustrates a fascinating degree of universality in aeronautical research. The NACA--born in response to European progress in aeronautics-- benefited through the employment of Europeans like Munk and Theodorsen, and profited from a continuous interaction with the European community.

In 1935, Jacobs went to Rome as the NACA representative to the Fifth Volta Congress on High-Speed Aeronautics. During the trip, he visited several European research facilities, comparing equipment and discussing the newest theoretical concepts. The United States, he concluded, held a leading position, but he asserted that "we certainly cannot keep it long if we rest on our laurels." On his way home, Jacobs stopped off at Cambridge University in Great Britain for long visits with colleagues who were investigating the peculiarities of high-speed flow, including statistical theories of turbulence. These informal exchanges proved to be highly influential on Jacobs' approach to the theory of laminar flow by focusing on the issue of pressure distribution over the airfoil. Working out the details of the idea took three years and engaged the energies of many individuals, including several on Theodorsen's staff, even though he remained skeptical.

Once the theory appeared sound, Jacobs had a wind tunnel model of the wing rushed through the Langley shop and tested it in a new icing tunnel that could be used for some low-turbulence testing. The new airfoil showed a fifty percent decrease in drag. Jacobs was elated, not only because the project incorporated complex theoretical analysis, but also because the subsequent empirical tests justified a new variable density tunnel.

In application, the laminar flow airfoil was used during World War II in the design of the wings for the North American P-51 Mustang, as well as some other aircraft. Operationally, the wing did not enhance performance as dramatically as tunnel tests suggested. For the best performance, manufacturing tolerances had to be perfect and maintenance of wing surfaces needed to be thorough. The rush of mass production during the war and the tasks of meticulous maintenance in combat zones never met the standards of NACA laboratories. Still, the work on the laminar flow wing pointed the way to a new family of successful high-speed airfoils. These and other NACA wing sections became the patterns for aircraft around the world.

ground view of a P51 Mustang
The NACA's laminar flow airfoil was first used on the North American XP-51 Mustang.

NACA reports began to emerge from an impressive variety of tunnels that went into operation during the 1930s. The refrigerated wind tunnel, declared operational in 1928, became a major tool for the study of ice formation on wings and propellers. In flight, icing represented a menace to be prevented at all costs. Langley's research in the refrigerated tunnel contributed to successful deicing equipment that not only enabled airliners to keep better schedules in the 1930s but also enabled World War II combat planes to survive many encounters with bad weather. Another facility at Langley, a free-spin wind tunnel, yielded vital information on the spin characteristics of many aircraft, improving their maneuverability while avoiding deadly spin tendencies. A hydrodynamics test tank solved many riddles for designers of seaplanes and amphibians, by towing hull models to simulated takeoff speeds.

The NACA also took a bold look ahead to much higher airplane speeds to come. In the mid-1930s, when speeds of 200 MPH were quite respectable, the agency proposed a "fullspeed" tunnel, providing the means for tests at a simulated 500 MPH. With an 8 foot diameter, the tunnel allowed tests of comparatively large models, as well as some full scale components. Completed early in 1936, the eight- foot tunnel played a major role in high-speed aerodynamic research, laying the foundations for later work in high subsonic speeds as well as the baffling transonic region.

As the research capabilities of the NACA expanded, so did the persistent, nagging problems that followed the introduction of successive generations of aircraft. For the NACA, one of the most unusual apparitions to appear in the 1930s was the autogyro. First developed by a Spaniard, Juan de la Cierva, in the 1920s, the autogyro was thought to have great promise in the immediate future. At first glance, it looked like a helicopter, with a huge multi- bladed rotor situated above the fuselage. Unlike the helicopter, the autogyro had stubby wings and used a nose-mounted engine with a conventional propeller for forward momentum. In moving ahead, the main rotor turned, so that its long thin airfoil blades provided lift, with some assistance from the shortened wings. The autogyro could not take off or land vertically, nor could it hover, but its abbreviated landing and takeoff runs were dramatic, and proponents claimed that the aircraft minimized dangerous stalls. Some writers of the era envisioned the autogyro as a replacement for the family sedan. Accordingly, the NACA bought a Pitcairn PCA-2 autogyro (designed and manufactured in Pennsylvania by Harold Pitcairn) and began tests in 1931. These trials did not contribute to a permanent niche in American life for the autogyro, but Langley was launched into continuing work on rotary-wing aircraft. In fact, some of the maneuverability tests and other investigations on the autogyro led to testing criteria used into the 1980s.

Flight research like that involving the autogyro marked this activity as an increasingly valued component of Langley's procedures. Accomplished on an ad hoc basis most of the time, flight testing became more formalized in 1932, when a flight test laboratory appeared at Langley. With separate space allocated for staff, shop work, and an aircraft hangar, the new laboratory made its own contributions to aviation progress during the 1930s.

ground view of an autogyro
Expanded flight test operations included evaluation of the Pitcairn autogyro.

Among the various airplanes that passed through Langley were two of the most advanced airliners of the era: the Boeing 247 and the Douglas DC-1, which led to the classic DC-3. The Boeing and Douglas designs incorporated the latest aviation technology that had evolved since the end of World War I. With the Ford Tri-Motor of the 1920s, wooden frame and fabric covering had given way to all-metal construction. Unlike the Ford, the Boeing and Douglas transports were low-winged planes with retractable landing gear, and their more powerful twin engines were cowled and mounted into the leading edge of the wings. At 170-180 MPH, they were considerably faster than any of their counterparts, and attention to details like soundproofing and other passenger comforts made them far more popular with travelers. Later versions of the Douglas transport, like the DC-3, added refinements like wing flaps and variable pitch propellers that made it even more effective in takeoffs and landings, as well as cruising at optimum efficiency at higher altitudes. But it was not clear what would happen if one of the two engines on the new transports failed. At the request of Douglas Aircraft, Langley evaluated problems of handling and control of a twin-engine transport with one engine out. These tests, conducted just six months before the DC-3 made its maiden flight, provided the sort of procedures to allow pilots to stay aloft until an emergency landing could be made.

The design revolution leading to all-metal monoplane transports had a similar impact on military aircraft. During 1935, Boeing began flight tests of its huge, four-engined Model 299, the prototype for the B-17 Flying Fortress of the Second World War. The big airplane's performance exceeded expectations, due in no small part to design features pioneered by the NACA. The Boeing Company sent a letter of appreciation to the NACA for specific contributions to design of the plane's flaps, airfoil, and engine cowlings. The letter concluded, "it appears your organization can claim a considerable share in the success of this particular design. And we hope that you will continue to send us your 'hot dope' from time to time. We lean rather heavily on the Committee for help in improving our work."

The ability of the NACA to carry out the sort of investigations that proved useful was often the result of continuing contacts with the aviation community. One of the most interesting formats for such ideas was the annual aircraft engineering conference, which began in 1926. Attendees included the movers and shakers from the armed services, the aviation press, government agencies, airlines, and manufacturers. These were busy people, and the NACA gave them a carefully orchestrated two-day visit to Langley, with plenty of time for conversation.

Over 300 people made each annual trip, an invitation only opportunity during the 1930s. The NACA's executive secretary, John Victory, became the principal organizer of the event, which had almost sybaritic overtones in a depression era. After gathering in Washington, the group boarded a chartered steamer for a stately cruise down the Chesapeake Bay to Hampton, Virginia. Once ashore, the travelers partook of a generous Southern breakfast at a local resort hotel, then headed for Langley in an impressive motorcade that numbered over 50 cars. The program included reviews of current projects, followed by smaller group tours, lab demonstrations, and technical sessions throughout the day. Conference participants motored back to the hotel for cocktails on the veranda, an elaborate banquet, and an overnight return cruise to Washington. Public relations played an obvious role in such outings, but the conferences represented a useful avenue for maintaining contact, for keeping a finger on the pulse of the aviation community, and for keeping the aviation community abreast of the NACA's latest research and facilities.

Although the NACA personnel may not have enjoyed luxurious perquisites on a daily basis, the agency continued to be a magnet for many young aeronautical engineers. Langley's impressive facilities in particular were a powerful lure, in addition to the opportunity to work closely with well-known people at the cutting edge of flight. Through the 1930s, Langley managed to maintain a degree of informality that provided a unique environment for newly hired personnel. John Becker, who reported for duty in 1936, remembered the crowded lunchroom where he found himself rubbing shoulders with the authors of NACA papers he had just been studying at college. "These daily lunchroom contacts provided not only an intimate view of a fascinating variety of live career models," he wrote, "but also an unsurpassed source of stimulation, advice, ideas, and amusement." The tables in the lunchroom had white marble tops. By the end of the lunch hour, the table tops were invariably covered by sketches, equations, and other miscellany, erased by hand or by a napkin and drawn over again. Becker lamented the loss of this "great unintentional aid to communication" when Langley's growing staff required a larger, modern cafeteria with unusable table surfaces.

Much of this growth--and the end of an era for Langley and the NACA--occurred during the wartime period. In 1938, the total Langley staff came to 426. Just seven years later, in 1945, Langley numbered 3000 personnel.

Military Research

The prewar research at Langley had a catholic fallout, in that the center's activities were applicable to both civil and military aircraft. The commercial aircraft and fighting planes of the first one-and-a-half decades following World War I were very similar in terms of airspeed, wing loading, and general performance. For example, Langley's work on the cowling for radial engines had the encouragement of both civil and military personnel, and the NACA cowling eventually appeared on a remarkable variety of light planes, airliners, bombers, and fighter aircraft. Many other NACA projects on icing, propellers, and so on were equally useful to civil and military designs.

About the mid-1930s the phenomenon of mutual benefits began to change. Commercial airline operators put a premium on safety and operational efficiency. While such factors were not shunned by military designers, the qualities of speed, maneuverability, and operations to very high altitudes meant that NACA research increasingly proceeded along two separate paths. By 1939, the Annual Manufacturers Conference was phased out and replaced by an "inspection," planned solely for representatives of the armed services and delegates from firms having military contracts.

For most of the time after the mid-1930s benchmark, military R&D took the lead in the NACA, and its fallout was incorporated into civilian airplanes. Moreover, there are indications that the U.S. Navy often fared better than the U.S. Army in reaping benefits from Langley's extensive R&D talents. This situation may have stemmed from Langley's early days, when there was some friction about civilian NACA facilities located at the Army's Langley Field. Old hands at the NACA felt that certain Army people wanted to shift the NACA's work to McCook Field in Ohio and to conduct all of its operations under an Army umbrella. Under the circumstances, the Navy appeared to have smoother relations with the NACA. At the same time, the Navy had reason to rely heavily on the NACA's expertise. During the 1920s and 1930s, the service developed its first aircraft carriers. Concurrently, a rather special breed of aircraft had to be developed to fit the demanding requirements of carrier operations. Landings on carriers were bone-jarring events repeated many times (a carrier landing was wryly described as a "controlled crash"); takeoffs were confined to the limited length of a carrier's flight deck. In the process of beefing up structures, improving wing lift, keeping aircraft weight down, enhancing stability and control, and studying other problems, naval aviation and the NACA grew up together. Between 1920 and 1935, the Navy submitted twice as many research requests as the Army.

There were still some instances in which civilian needs benefited military programs. In 1935, Edward P. Warner, Langley's original chief physicist, was working as a consultant for the Douglas Aircraft Company. Warner had the job of determining stability and control characteristics of the DC-4 four-engined transport. Accepted practice of the day usually meant informal discussions between pilots and engineers as the latter tried to design a plane having the often elusive virtues of "good flying qualities." At Warner's request the NACA began a special project to investigate flying qualities desired by pilots so that numeric guidelines could be written into design specifications. At Langley, researchers used a specially instrumented Stinson Reliant to develop usable criteria. Measurable control inputs from the test pilot were correlated with the plane's design characteristics to develop a numeric formula that could be applied to other aircraft. Further tests on 12 different planes gave a comprehensive set of figures for both large and small aircraft. As military programs gained urgency in the late 1930s, the formulas for flying qualities were increasingly used in the design of new combat planes.

The growing international threat found the American aviation industry in far better shape than was the case on the eve of World War II. In terms of civil aviation, the United States had established an enviable record of progress. Commercial airliners like the DC-3 had set a world standard and, in fact, were widely used by many foreign airlines on international routes. Airline operations had reached new levels of maturity, not only in terms of marketing and advertising to attract a growing clientele, but also in a myriad variety of supporting activities. These included maintenance and overhaul procedures, radio communication, weather forecasting, and long-distance flying. Many of these skills proved valuable to the military after the outbreak of war. Pan American World Airways (Pan Am), which had pioneered long distance American routes throughout the Caribbean, Pacific, and Atlantic shared its skills and personnel to help the Air Transport Command evolve a remarkable global network during the war years. Pan Am relied on a series of impressive flying boats designed and built by Sikorsky, Martin, and Boeing during the 1930s. Although the military airlift services depended more on land-planes like the DC-3 (military version known as the C-47) and DC-4 (or C-54), many of the imaginative design concepts of the flying boats pointed the way to the multi-engined airliners that replaced them.

There were even benefits for the light plane industry. Despite the depression, personal and business flying became firmly entrenched in the American aviation scene. Manufacturers offered a surprising array of designs, from the economical two-place Piper Cub J-3 to the swift 45 place business planes produced by Stinson and Cessna. At the top of the scale the Beech D-18, a twin-engine speedster, offered the era's ultimate in corporate transportation. When war came, these and other manufacturers were ready to turn out the dozens of primary trainers (larger planes for navigational and bombing instruction) and various components that made up the other equipment in the U.S. armed forces.

The Air Force itself was beginning to receive the sort of combat planes that enabled it to meet aggressive fliers in the skies over Europe and the Far East. Prewar fighters like the Curtiss P-40 soon gave way to the Lockheed P-38, Republic P-47, and North American P-51. A new family of medium bombers and heavy bombers included the redoubtable B-17 Flying Fortress, derived from the Boeing 299. Aboard the U.S. Navy's big new aircraft carriers, biplanes had given way to powerful monoplanes like the Grumman Wildcat, followed by the Hellcat and Vought Corsair. There were also new dive bombers and long-legged patrol planes like the Catalina amphibian. Directly or indirectly, the majority of these aircraft profited from the NACA's productivity during the 1930s as well as during the war.

The War Years

Even though Langley and the NACA had contributed heavily to the progress of American aviation, there were still some in Congress who had never heard of them. Before World War II, a series of committee reports brought a dramatic change. During the late 1930s, John Jay Ide, who manned NACA's listening post in Europe, reported unusually strong commitments to aeronautical research in Italy and Germany, where no less than five research centers were under development. Germany's largest, located near Berlin, had a reported 2000 personnel at work, compared to Langley's 350 people. Although the Fascist powers were developing civil aircraft, it became apparent that military research absorbed the lion's share of work at the new centers. Under the circumstances, the NACA formed stronger alliances with military services in the United States for expansion of its own facilities.

In 1936, the agency put together a special committee on the relationship of NACA to National Defense in time of war, chaired by the Chief of the Army Air Corps, Major General Oscar Westover. Its report, released two years later, called for expanded facilities in the form of a new laboratory--an action underscored by Charles Lindbergh, who had just returned from an European tour warning that Germany clearly surpassed America in military aviation. A follow-up committee, chaired by Rear Admiral Arthur Cook, chief of the Navy's Bureau of Aeronautics, recommended that the new facility should be located on the West Coast, where it could work closely with the growing aircraft industry in California and Washington. Following congressional debate, the NACA received money for expanded facilities at Langley (pacifying the Virginia Congressman who ran the House Appropriations Committee) along with a new laboratory at Moffett Field, south of San Francisco. The official authorization came in August 1939; only a few weeks later, German planes, tanks, and troops invaded Poland. World War II had begun.

The outbreak of war in Europe, coupled with additional warnings from the NACA committees and from Lindbergh about American preparedness, triggered support for a third research center. British, French, and German military planes were reportedly faster and more able in combat than their American counterparts. Part of the reason, according to experts, was the European emphasis on liquid-cooled engines that yielded benefits in speed and high altitude operations. In the United States, the country's large size had led to the development of air-cooled engines that were more suited to longer ranges and fuel efficiency. Moreover, according to Lindbergh, the NACA's earlier agreement to leave engine development to the manufacturers left the country with inadequate national research facilities for aircraft engines. Congress quickly responded, and an "Aircraft Engine Research Laboratory" was set up near the municipal airport in Cleveland, Ohio. This third new facility in the midwest gave the NACA a geographical balance, and the location also put it in a region that already had significant ties to the powerplant industry.

The site at Moffett field became Ames Aeronautical Laboratory in 1940, in honor of Dr. Joseph Ames, charter member of the NACA and its longtime chairman. The "Cleveland laboratory" remained just that until 1948, when it was renamed the Lewis Flight Propulsion Laboratory, in memory of its veteran director of research, George Lewis. Key personnel for both new laboratories came from Langley, and the two junior labs tended to defer to Langley for some time. By 1945, after several years of managing their own wartime projects, the Ames and Cleveland laboratories felt less like adolescents and more like peers of Langley. The NACA, like NASA after it, became a family of labs, but with strong individual rivalries.

Brewster Buffalo is mounted in front of the wind tunnel for testing
Drag reduction studies on the Brewster XF2A-1 Buffalo influenced many later military fighters.

In the meantime, requirements of national security took priority. One significant project undertaken on the eve of World War II demonstrated the sort of work at Langley that had a major influence on aircraft design for years afterward. During 1938, the Navy became frustrated with the performance of a new fighter, the XF2A Brewster Buffalo. After the navy flew a plane to Langley, technicians set it up in the full scale tunnel for drag tests. It took only five days to uncover a series of small but negative aspects in the plane's design.

To the casual eye, the 250 MPH fighter with retractable gear appeared aerodynamically "clean." But the wind tunnel evaluations pinpointed many specific design aspects that created drag. The exhaust ports, gunsight, guns, and landing gear all protruded into the slipstream during flight; the accumulated drag effects hampered the plane's performance. By revamping these and other areas, the NACA reported a 10 percent increase in speed. Such a performance improvement, without raising engine power or reducing fuel efficiency, immediately caught the attention of other designers. Within the next two years, no fewer than 18 military prototypes went through the "cleanup" treatment given to the XF2A. Even though the Brewster Buffalo failed to win an outstanding combat record, others did, including the Grumman XF4F Wildcat, the Republic XP47 Thunderbolt, and the Chance Vought XF4N Corsair. The enhanced performance of these planes often represented the margin between victory and defeat in air combat. Moreover, specialists in the analysis of engine cooling and duct design later set the guidelines for inducing air into a postwar generation of jet engines.

The pace of war created personnel problems, especially when selective service began to claim qualified males after 1938. In the early years of the war, NACA personnel officers did considerable traveling each month to get deferments for employees working on national defense projects. Nonetheless, the NACA sometimes lost more employees than it was able to recruit. The issue was not resolved until early in 1944, when all eligible Langley employees were inducted into the Air Corps Enlisted Reserves, then put on inactive status under the exclusive management of NACA. The NACA draftees were given honorable discharges after Japan's surrender in 1945. The issue of the draft was not a threat to women, who made up about one-third of the entire staff by the end of the war. Although most of the female employees held traditional jobs as secretaries, increasing numbers held technical positions in the laboratories. Some did drafting and technical illustrating; some did strain-gauge measurements; others made up entire computing groups who worked through reams of figures pouring out of the various wind tunnels. A few held engineering posts. If women at Langley did not advance as rapidly in civil service as their male counterparts, most of the female employees later recalled that their treatment at the NACA was better than average when compared to other contemporary employers.

a man and woman are pictured measuring a wing
More women joined the NACA during World War II; technicians prepaired wind tunnel models, like this flying boast wing, for realistic tests.

Over the course of the war years, the NACA's relationship with industry went through a fundamental change. Since its inception, the agency refused to have an industry representative sit on the main committee, fearing that industry influence would make the NACA into a "consulting service." But the need to respond to industry goals in the emergency atmosphere of war led to a change in policy. The shift came in 1939, when George Mead became vice-chairman of the NACA and chairman of the Power Plants Committee. Mead had recently retired as a vice-president of the United Aircraft Corporation, and his position in the NACA, considering his high level corporate connections, represented a new trend. During the war, dozens of corporate representatives descended on Langley to observe and actually assist in testing. In the process, they forged additional direct links between the NACA and aeronautical industries.

aerial photo of a squadron of P-38s
Early in the war, extensive analysis of the Lockheed P-38 Lightning solved problems in high-speed dives.

Much of the wartime work involved refinement of manufacturers' designs, ranging from fighters through bombers like the B-29. Aircraft as large as the B-29 design were not tested as full sized planes, but considerable data was generated from models. During 1942, the B-29 design was thoroughly investigated in Langley's 8-foot high-speed tunnel, and Boeing engineers heaped praise on Langley technicians for their cooperation and the high quality of the data generated by the tests.

Despite the success of American warplanes, two of the major aeronautical trends of the era nearly escaped the NACA's attention. The agency endured much criticism in the postwar era for its apparent lapse in the development of jet propulsion and in the area of high-speed research leading to swept wings. America's rapid postwar progress in these fields suggest that there may have been a lapse of sorts, although not as total as many critics believed.


There was nothing in the original NACA charter that charged it with research in rocketry. Some of the NACA's personnel had a personal interest in rocketry, but most early developments in this field came from sophisticated amateur associations like the American Interplanetary Society. During World War II, governments suddenly became more interested in rocketry as a powerful new weapon.

The existence of organized groups like the VfR in Germany signaled the increasing fascination with modern rocketry in the 1930s, and there was frequent exchange of information among the VfR and other groups, like the British Interplanetary Society (1933) and the American Interplanetary Society (1930). Even Goddard occasionally had correspondence in the American Interplanetary Society's Bulletin, but he remained aloof from other American researchers, cautious about his results, and concerned about patent infringements. Because of Goddard's reticence, in contrast to the more visible personalities in the VfR, and because of the publicity given the German V-2 of the Second World War, the work of British, American, and other groups during the 1930s has been overshadowed. Their work, if not as spectacular as the V-2 project, nevertheless contributed to the growth of rocket technology in the prewar era and to the successful use of a variety of Allied rocket weapons in the Second World War. Although groups like the American Interplanetary Society (which became the American Rocket Society in 1934) succeeded in building and launching several small chemical rockets, much of their significance lay in their role as the source of a growing number of technical papers on rocket technologies.

But rocket development was complex and expensive. The cost and the difficulties of planning and organization meant that, sooner or later, the major work in rocket development would have to occur under the aegis of permanent government agencies and government-funded research bodies. In America, significant team research began in 1936 at the Guggenheim Aeronautical Laboratory, California Institute of Technology, or GALCIT. In 1939, this group received the first federal funding for rocket research, achieving special success in rockets to assist aircraft takeoff. The project was known as JATO, for jet-assisted takeoff, since the word "rocket" still carried negative overtones in many bureaucratic circles. JATO research led to substantial progress in a variety of rocket techniques, including both liquid and solid propellants. Work in solid propellants proved especially fortuitous for the United States; during the Second World War, American armed forces made wide use of the bazooka (an antitank rocket) as well as barrage rockets (launched from ground batteries or from ships) and high velocity air-to-surface missiles.

The most striking rocket advance, however, came from Germany. In the early 1930s the VfR attracted the attention of the German army, since armament restrictions introduced by the Treaty of Versailles had left the door open to rocket development. A military team began rocket research as a variation of long-range artillery. One of the chief assistants was a 22-year-old enthusiast from the VfR, Wernher von Braun, who joined the organization in October 1932. By December, the army rocket group had static-fired a liquid propellant rocket engine at the army's proving grounds near Kummersdorf, south of Berlin. During the next year it became evident that the test and research facilities at Kummersdorf would not be adequate for the scale of the hardware under development. A new location, shared jointly by the German army and air force, was developed at Peenemuende, a coastal area on the Baltic Sea. Starting with 80 researchers in 1936, there were nearly 5000 personnel at work by the time of the first launch of the awesome, long-range V-2 in 1942. Later in the war, with production in full swing, the work force swelled to about 18,000.

Having completed his doctorate in 1934 (on rocket combustion), von Braun became the leader of a formidable research and development team in rocket technology at Peenemuende. Like so many of his cohorts in original VfR projects, von Braun still harbored an intense interest in rocket development for manned space travel. Early in the V-2 development agenda, he began looking at the rocket in terms of its promise for space research as well as its military role, but found it prudent to adhere rigidly to the latter. Paradoxically, German success in the wartime V-2 program became a crucial legacy for postwar American space efforts.