[135] 1-by 3-Foot Tunnels. The Ames 1- by 3-foot supersonic wind tunnels were completed and first operated in August 1945. The manufacturer of the jack-operated flexible throat, however, had trouble perfecting his product and it was another year and a half before the flexible throat was ready for use. In the meantime the tunnels were operated with fixed throats. In the case of the continuous-flow tunnel, one throat was designed for a Mach number of 1.5 and the other for a Mach number of 2.0.
Finally the flexible throats arrived and were installed. They worked very poorly. The motor-driven screw jacks were controlled by cams and microswitches. The control was not sufficiently precise and the curvature of the flexible plates had to be checked by hand. Since it sometimes took as much as 2 or 3 days to make a throat and speed change, such changes were avoided. By 1949, Ames engineers felt that they could not tolerate the nuisance much longer. They submitted a proposal to Headquarters for new nozzles (throats) for the 1- by 3-foot tunnels, which would be improved versions of the slidingblock nozzle earlier designed for the 6-by-6. Included in this proposal was a plan to increase the operating pressure of the 1-by-3 No. 1 and thus also its Reynolds number range. The proposal was not approved, however, and before it was resubmitted, the plan to use sliding-block nozzles in the 1- by 3-foot tunnels had been abandoned.
12-Foot Tunnel. Robert Crane had been put in charge of the 12-foot tunnel and George Edwards was his assistant. The tunnel made its first run on July 5, 1946, and the next 9 months or so were spent in calibration and shakedown tests. These tests confirmed the low turbulence level of the tunnel. The first test of a research nature, of a low-aspect-ratio triangular wing, was run on May 6, 1947. Research work continued until January 1949 when four blades of the fan were found to be cracked; all blades had then to be replaced. This emergency operation delayed research for more than 6 months.
[137] In a tunnel pressurized to 6 atmospheres, the cracking of fan blades is a serious matter. In this case its discovery before blade failure was only a matter of luck. Ames engineers were aware that blades of essentially the same design had been used in the new Caltech Cooperative Wind Tunnel. The blades in both cases were different from those used in ordinary tunnels as they had to be of variable pitch to accommodate wide variations in wind-tunnel pressure. When a serious blade failure occurred in the Co-op Tunnel, Bob Crane immediately inspected those in the 12-foot fan and it was only then that the cracks in the four blades were discovered. Thus Ames profited by Caltech's misfortune. The blades were redesigned and no more trouble occurred. What would have happened if one of the 12-foot blades had let loose is not known for sure; but, in anticipation of such a contingency, the tunnel wall in the plane of the fan had been heavily reinforced.
Low-Density and Heat-Transfer Tunnels. Two new men appearing on the scene at Ames at this time were Jackson Stalder and Glen Goodwin. They were working under Alun Jones in the Flight Engineering Section. Being original thinkers as well as hardheaded engineers, they wanted to do something different but were not quite sure what. They became intrigued with the problems of the high-speed, high-altitude missiles then being discussed by the aeronautical avant-garde and more specifically with the notion of putting wings on the V-2 missile-a notion that Eugen Sanger, a German scientist, had mentioned. Of interest to Jack and Glen were the aerodynamic forces to which such a missile would be subjected while flying at very high altitudes-way out where the air molecules are so far apart that they act as individuals rather than as members of a close-packed team. "Why are you interested in aerodynamics where there's no air?" Jack was frequently asked. His reply often seemed a little vague but his interest in the subject persisted.
Jack and Glen, supported by Morris Rubesin, a new arrival, got permission to build a small, inexpensive "low-density" tunnel. The tunnel, which had a test section of approximately 2 by 2 inches, was of a nonreturn type through which air was induced to flow by means of an evacuated tank at the exit. Very low pressures were achieved in the tank, and thus in the test section, by a combination of mechanical and oil-diffusion pumps. The tunnel was located under the return passage of the big 40-by-80 where it could draw power for its pumps from the 40-by-80 power supply. As the tunnel approached completion in 1948, it was learned that a similar tunnel was being built at the University of California under the direction of Dr. Sam Schaaf.
Glen Goodwin and Morrie Rubesin had become interested in the heating that occurred in the boundary layers of high-speed aircraft and they Sought and secured permission to build a small "heat-transfer" wind tunnel. This tunnel, which was designed largely by Thor Tendeland, was of a [138] closed-circuit, continuous-flow type having a fixed 6- by 6-inch supersonic throat designed for Mach 2.4. It also, for power-supply reasons, was placed under the 40-by-80. The low-density tunnel began operation in 1948, and the heat-transfer tunnel a little later. They were combined in a low-density heat-transfer (LD-HT) section under Jack Stalder who reported to Harry Goett, Chief of the Full Scale and Flight Research Division.
Hypersonic Facilities. In addition to the LD and HT tunnels, two other advanced facilities were proposed in 1946. One was a 10- by 14-inch hypersonic (Mach 6 or 7) tunnel proposed by Al Eggers, and the other was a supersonic free flight (SSFF) tunnel conceived and proposed by Harvey Allen. Funds for each of these facilities, in amounts of about $125,000, were....
....authorized by Congress in July 1947. The low cost of each facility was made possible by a plan to use the compressors of the 12-foot tunnel as a source of power.
Justification for the new facilities was based on the need for investigating the aerodynamic characteristics of long-range ballistic missiles, such as the German A-9, which would fly at Mach numbers of 7 or more. Reportedly, certain people in NACA Headquarters, principally Dr. Hunsaker, did not see the need for hypersonic tunnels at that time, but these opposing forces yielded to persuasion and the low cost of the proposed facilities made the persuasion easier.
10- by 14-Inch Tunnel. For convenience in the use of the 12-foot compressor system, it was planned to house the 10- by 14-inch tunnel in a new structure attached to the 12-foot auxiliaries building. The compressors which pressurized the 12-foot tunnel to 6 atmospheres were large enough to Operate a tunnel of about 1-square-foot test section at a Mach number of 3.0; and thus, since mass flow decreases with increasing supersonic Mach number, they should theoretically be able to supply more than enough air to operate the tunnel at a Mach number of 6 or 7. The problem was not so.....
....much with the volume of air available as with the maximum pressure-6 atmospheres. A peculiar characteristic of a supersonic tunnel is that it requires a much higher pressure for starting than for continuous operation. The 6 atmospheres of pressure available from the 12-foot compressor could easily start a Mach 3 tunnel, but starting a Mach 6 tunnel would take 30 atmospheres-a pressure ratio of 30 to 1. If, however, the nozzle were designed with variable geometry, the tunnel could be started at Mach 3 and then quickly increased in speed to Mach 5 or 6. The 12-foot-tunnel air supply could then be utilized with maximum effectiveness. But variable-geometry throat systems were known to be very complicated and expensive and their construction seemed scarcely consistent with the limited funds available for tunnel construction. A1 Eggers, however, exercised his ingenuity and came up with the design of a special double-hinged type of double-throated nozzle that was relatively inexpensive and would provide the desired operating characteristics. The system required the use of suction at the nozzle exit to increase the operating pressure ratio and the use of a second throat with boundary-layer removal to increase the efficiency with which the air could be decelerated after passing through the test section.
After the system details for the 10- by 14-inch tunnel had been worked out through model tests, there remained one troublesome problem: air condensation. As air accelerates in the test section of a wind tunnel, not only [141] does its pressure fall but so does its temperature. In tunnels that reach high subsonic or supersonic speeds, the cooling which occurs in the throat causes any moisture in the air to condense as fog. This problem is regularly solved by drying the air before use. But as the speed of a wind tunnel increases to high supersonic levels, the temperature in the test section falls so low that the air itself begins to condense, or liquefy. This situation completely upsets the energy balance in the air, distorts the flow pattern, and limits the speed of a wind tunnel to about Mach 5. In the design of the 10- by 14-inch tunnel, the air-liquefaction problem was thoroughly investigated in a model tunnel. The best solution, it was found, was to heat the air as it entered the tunnel. About 350° F of heating was required to permit tunnel operation at a Mach number of 6.0. This heating, it was determined, could best be achieved in the 10- by 14-inch tunnel by means of a 300-kilowatt electrical heater.
The 10- by 14-inch tunnel was still under construction at the end of 1949; but its operating group, headed by Alfred Eggers, was scheduled to become a Section in Allen's High Speed Research Division.
Supersonic Free-Flight Tunnel. It was pretty clear that wind tunnels had serious limitations for simulating conditions of high-speed missile flight. The heating required to prevent air liquefaction at Mach numbers over 7 or 8 was difficult to achieve and the resulting high inlet temperature would certainly be a troublesome factor in the operation of a wind tunnel. An-...
....-other problem was that the Reynolds number of a tunnel such as the 10-by-14 had the unfortunate characteristic of decreasing with speed. Such considerations led Harvey Allen to believe that some new kind of facility was required to simulate conditions of extremely high-speed flight. The feasibility of attempting such simulations in steady-state, continuously operating wind tunnels was becoming increasingly doubtful. The temperatures, pressures, velocities, costs, and everything else were just too high. It now appeared desirable to build facilities in which the extreme conditions of flight would be simulated only fleetingly. The test measurements would be vastly more difficult to make and the data output of the facility would be very low, but these disadvantages might be tolerable if test speeds could be substantially increased.
Allen was aware of the ballistics range used by armament manufacturers. Presumably one could shoot a model instead of a bullet down the range, assuming that the model could be made strong enough to stand the very high accelerations involved. The fastest guns had muzzle velocities of only 4000 feet per second, but by redesign they might reach speeds of 6000 or 8000 feet per second. Such redesign might also be able to provide a more uniform, sustained impulse that would reduce structural loads on the model. These ideas involved nothing particularly new, but Harvey figured that the scheme might be carried a few steps farther. Inasmuch as the speed of sound is lower at low temperatures, it appeared that the Mach number of a test could be increased 15 percent if the model were fired into an air chamber refrigerated to about -70° F, corresponding to air temperatures a missile might ordinarily encounter in flight. A still better method would be to shoot the model upstream in a supersonic wind tunnel of moderate Mach number. In such a wind tunnel, the air temperature would be just about right and the air velocity would add to the relative Mach number of the model. A Mach number of perhaps 10 or 12 could thus be achieved and the Reynolds number would increase with speed as it does in flight rather than [143] decrease with speed as it usually does in a hypersonic wind tunnel. There would also be no model-support interference to worry about.
These, then, were the principles upon which the design of the supersonic free-flight wind tunnel (SSFF) was based. The idea was a Harvey Allen original; however, the implementation of the idea may have required more genius than the conception. The perfection and full exploitation of the SSFF tunnel test technique was a process that continued for years and required the ingenuity of many people in the High Speed Research and the Research Instrument Divisions.
The new tunnel was located in an addition to the 1- by 3-foot tunnel building immediately adjacent to the blowdown tunnel. Indeed, the supersonic nozzles used were the fixed nozzles of the blowdown l-by-3 which by now had been replaced with flexible nozzles. One of these nozzles was redesigned for Mach 2.0 and the other for Mach 3.0. A program of gun development also got under way. The guns, procured from the military, ranged in caliber from 0.22 inch to 3 inches. The thrust of the guns was often transmitted to the models through sabots which peeled off cleanly as the model left the gun. A special catcher was installed in the tunnel to recover the model after it had passed through the test section.
The test section of the SSFF tunnel was elongated and in it a series of windows was installed through which shadowgraph pictures were taken. The timing mechanism and other measuring equipment were of unique design and of remarkable precision. The instrumentation not only provided shadowgraph pictures of the flow pattern around the test model as it flew past the windows but also allowed a quantitative determination of the lift, drag, and center of pressure of the air forces to which the model was being subjected.
The supersonic free-flight tunnel was completed late in 1949 but did not become productive until later. Its operating group, first headed by Victor Stevens, became a Section of the High Speed Research Division.
Helium Tunnel. In the development of facilities for investigating the hypersonic aerodynamics of missiles, the 10-by-14 and the SSFF did not exhaust the ideas of Ames engineers. They proposed in 1948 the construction of a 1- by 1-foot blowdown tunnel that would operate with compressed helium gas. Gases other than air, specifically Freon, had been used earlier in a wind tunnel at Langley; the peculiar advantage of helium was that its liquefaction temperature was so low that it could operate in a wind tunnel, without liquefying, at Mach numbers up to 25. Another factor favoring the use of helium at Ames was that storage and transfer facilities for the gas existed at Moffett Field, left over from the days when blimps were operated from the base.
Countering the advantages just noted was the question of whether flight conditions in air could properly be simulated in a wind tunnel using....
.....helium. Helium is a monatomic gas and the ratio of its specific heats, y, is quite different from that of air. These characteristics might affect simulations at high speeds where the thermodynamic properties of the gas are especially important. On the other hand, it might be possible to make an allowance for the thermodynamic differences between helium and air. Besides, how else was one to obtain data, good or bad, at a Mach number of 20? The 10-by-14 apparently was operable only Up to Mach 6 or so, and the limits of the SSFF appeared to be about 12. Therefore was not the 1- by 1-foot helium tunnel worth the gamble of an estimated $330,000? Ames engineers [145] thought so. NACA management thought not. The proposal, made in fiscal year 1949, was turned down.
6- by 6-Foot Supersonic Tunnel. The 6- by 6-foot supersonic tunnel was first operated on June 16, 1948. Charles Frick was in charge. In one of the early runs the motor that drove the huge sliding block in the throat suddenly stalled with an awful groan. The block would not move. The side plates were removed from the throat to see what was wrong. The wind-tunnel gang and Carl Bioletti, who had designed that portion of the tunnel structure' stood waiting expectantly. When the walls had been removed, the sides of Harvey s beautifully polished and expensive sliding block, as well as the walls themselves, were found to have been badly scored. Someone had goofed. The sidewalls had not been sufficiently stiff, had deflected inward under internal suction loads, and had seized the block. Was the block ruined? It looked pretty bad. Red Betts, the fixer, was called in. His expression as he viewed the mutilated surfaces was somber indeed. "What do you think, Red?" asked Bioletti. After due consideration, Red shook his head and replied, "Better get a rope." "What can we do with a rope?" Carl queried. "Hang yourself before the boss finds out," said Red, still unsmiling. As it turned out, Carl didn't take Red's advice; and Red, demonstrating once again his mechanical genius, quickly had the gouges filled up with a metal filler of some kind and the block and wall surfaces again as smooth as glass. The sidewalls were stiffened with tremendous I-beams and gave no further trouble. The design fault was an oversight for which Carl took the blame, although he had gone to the trouble of having his design checked by other people, none of whom had observed the weakness.
As had been expected, the fabrication of the 50-inch-diameter schlieren windows for the 6- by 6-foot tunnel turned out to be a difficult task. Corning was the only glass company that would attempt to produce the required flaw-free window blanks. The contract called for Corning to produce four blanks which then would be ground and polished by the Tinsley Laboratories of Berkeley, California. The technique was to pour the blanks and let them cool (anneal) at a precisely controlled rate for 9 months. The first two blanks produced in this manner were at least sound, but the next two, after the annealing period, were found to be cracked. So also, on another try, were the following two blanks. Corning engineers were discouraged but were induced to try two more blanks with the mold temperature a little higher-equal in fact to the temperature of the glass as poured. Happily this attempt was successful. The blanks came out uncracked. Corning was reported to have considered the pouring of the 6-by 6-foot-tunnel window blanks the most difficult task it had undertaken-even more difficult than the pouring of the 200-inch Pyrex blanks for the mirror of the Mount Palomar telescope.1 But although the window blanks were structurally sound,....
....they were found, on polishing, to be not completely free of striae and other internal imperfections. The second pair was better than the first in this regard and, in any case, Harvey Allen was able to find a way to minimize the effects of the imperfections on schlieren pictures.
Other Construction. The new hangar was completed in 1946, and early in 1949 construction got under way on a new instrument research building. Also undertaken, late in 1949, was the construction of an administrative building annex intended to augment the capacity of the main administration building which, almost from the first, had proven to be too small.
The general feeling seemed to be that, once an airplane was well into the supersonic range of flight, the conditions it would encounter should be fairly stable. This belief seemed to be confirmed by the first supersonic flights of the XS-1. There was much concern, however, over the wildly disturbed mixed-flow conditions that prevailed in the transonic range, and this range had to be traversed twice in every supersonic flight. The transonic zone was obviously a regime of flight that required a great deal of study and, if supersonic flight of operational airplanes was to be achieved in the near future, the study was of a most urgent character. Unfortunately, through an ironic twist of nature, the transonic range was one in which wind tunnels would not work properly. According to Dr. Dryden, it was a "blind spot" in the spectrum of tunnel operation. Subsonic tunnels choked by the time they reached Mach 0.8 or 0.9, and supersonic tunnels did not function properly at Mach numbers much below 1.2. In between there was choking and a mishmash of shock waves reflected between model and tunnel walls that precluded any true simulation of actual flight conditions.
Faced with the situation just mentioned, ingenious engineers went to....
....work to devise alternative methods for acquiring design data in the transonic range. At Langley, Bob Gilruth, in 1944, found that transonic data could be obtained by mounting a small test airfoil in the accelerated-flow region over the wing of a high-speed airplane such as the P-51. This technique, called the "wing-flow method," produced some useful data but at very small scale. Langley also, in 1945, established a pilotless-aircraft research station at Wallops Island, Virginia. Here transonic and supersonic data were returned by telemeter from rocket-launched models that later fell into the sea. This technique was made possible by the multichannel telemeter which, incidentally, had been developed in 1941-1942 for aircraft flight testing by Harvey Giffen of Vultee Aircraft, Inc.2 On the whole, the methods used at Wallops, though effective, were expensive and technically difficult.
The next step in developing transonic test methods came in 1946, when Lockheed and NACA engineers simultaneously observed that the wing-flow method could be applied to wind-tunnel testing by installing a bump, simulating the wing, on the floor of a high-subsonic-speed wind tunnel. At times the bump technique was applied in the 16-foot tunnel while the wing-flow method was used in flight.
In 1946 the Flight Engineering Section at Ames foresaw the end of the [148] deicing work and proposed a continuing program of research in the general field of aircraft operating problems. This proposal was turned down by NACA management. Then along in 1947 Harry Goett, who was in general command of the flight engineering activity, suggested to NACA Headquarters that Ames set up a pilotless-aircraft test operation similar to the one being established by Langley at Wallops. Dr. Dryden was opposed to having Ames duplicate Langley's efforts in developing rocket-launching and telemetry techniques, but he did not object when Harry proposed the dropping of recoverable models from a high-flying airplane. Thus as the icing work began to phase out in 1947, Ames developed the technique for recovering intact, by means of air brake and parachute, instrumented test models dropped at high altitudes from an airplane. In this way aerodynamically clean models, if dropped from a sufficiently high altitude, would traverse the transonic range and, indeed, reach low supersonic speeds before they had to be braked for a landing.
The airplanes chosen by Ames engineers for the drop operation were a group of three Northrop P-61 "Black Widow" night fighters of which one, intended for photoreconnaissance uses, had been equipped with a turbosupercharger. Another one, owing to the relative scarcity of P-61 airplanes, had been borrowed, for cannibalization purposes, from the museum of the Smithsonian Institution. In the drop operation, the supercharged P-61 was flown to altitudes up to 42,000 feet. As it did not have a pressure cabin, the physical stamina of the pilots was sorely taxed. But useful data were obtained and the development of the recovery technique, a notable accomplishment in itself, was helpful to other agencies later in attempts to recover expended missiles. The greatest contributors to the development and use of the drop technique at Ames were Alun Jones, James Selna, Bonne Look,...
....and Loren Bright. Among the pilots who flew the P-61 for the drop tests were George Cooper, Rudolph Van Dyke, and Robert Whempner of Ames and Joseph Walker of the NACA High Speed Flight Station at Edwards, California.
The methods so far advanced for obtaining transonic data were slow, complex, costly, or otherwise not wholly satisfactory. NACA had no intention of giving up its efforts to make wind tunnels operate in the transonic range, and the matter was being actively pursued by John Stack and his staff at Langley. These efforts bore fruit in January 1947 when Ray Wright and Vernon Ward, who worked under Stack, tested a model of a "slotted-throat" tunnel By means of this test, and much additional work, Langley found that the installation of a number of suitably shaped slots in the walls of the test section of a wind tunnel would eliminate the choking phenomenon and suppress the shock-wave reflection. With this modification, a wind tunnel could provide a reasonably true simulation of transonic flight conditions. Tunnels capable of transonic operation were nevertheless of a rather special design, and it was not until December 1949 that Langley completed its first transonic wind tunnel. Following Langley's example there was a great rush all over the country to build transonic tunnels, and the wing-flow and bump methods of transonic testing quickly disappeared. The Ames Laboratory converted the 1- by 3 1/2-foot tunnel for transonic operation by drilling holes in the top and bottom walls. Sliding plates were used to open or close the holes to the degree desired. A simple flexible throat was also added. Additionally, Ames proposed that the 16-foot be converted into a transonic tunnel.
Perhaps nothing more clearly revealed the revolution in aeronautical thinking in the early postwar period than a program of facility planning, then under way, that was known as the "Unitary Plan." Never before had so grandiose a wind-tunnel building program been seriously proposed by responsible people, and never before had the desires of interested groups been so thoroughly canvassed in establishing a facilities program. The tremendous scope of this program, which was at first expected to cost over a billion dollars, gave evidence of the importance which knowledgeable people now attached to aeronautical development. At the doorstep of realization was a vast and wonderful array of transonic and supersonic airplanes, guided missiles, and the portentous hypersonic intercontinental ballistic missile. Such developments would require many facilities so extensive and costly that they must be planned on a national scale.
NACA, of course, would need new facilities for research. The military would need new facilities for test and evaluation. The Air Force, indeed, was firmly resolved to establish itself in the field of aeronautical research and development and had set its sights on a new air engineering development center. It was also considered desirable to provide universities with high-speed wind tunnels to acquaint them better with, and improve their ability to teach, the new disciplines of aeronautical science. Many aircraft companies had by now acquired their own subsonic wind tunnels but would have to rely on the Government to make available the costly transonic, supersonic, and hypersonic wind tunnels required for future aircraft development. Finally, the planners recognized that a number of the facilities proposed would require vast amounts of power for their operation. These, it was felt, could best be accommodated in a new supersonic research center, operated by NACA, and located near the Grand Coulee or the Hoover Dam.
Since the program was of national scope and covered the needs of everyone, it was called the "Unitary Plan"-a name proposed by Dr. Vannevar Bush. The planning began with the Air Force late in 1945, was picked up by NACA in 1946, and was carried on by a galaxy of organizations and people in 1947, 1948, and 1949. Special panels to deal with the problem were formed in NACA and some of NACA's regular technical committees became deeply involved. Various military groups were active in the planning, as were the Joint Research and Development Board, the President's Air Policy Board, and the Congressional Aviation Policy Board. Industry was thoroughly integrated into the planning councils through membership on NACA and military committees and panels. The universities also entered the planning through membership on NACA committees. Finally, and perhaps fortunately, there were the Appropriation Committees of Congress which remained singularly calm about the whole matter.
[151] The contributors to the Unitary Plan, most of whom were normally sane and sound individuals, fed upon each other's enthusiasm with the result that a truly remarkable state of euphoria developed. The atmosphere of the planning councils was notably inflationary. The plans rapidly mushroomed, the proposed facilities became more numerous, more pretentious and costly, and many were quite beyond the state of design knowledge. Of course the Unitary Plan was intended to be a 10-year program, but it took a brave man in the field of aeronautics to look ahead 10 years.
In any case, everyone's wants were collected into a huge pile which was then consigned, for organizing into a sensible program, to a Special Committee on Supersonic Facilities headed by Dr. Jerome C. Hunsaker, the staid and notably conservative Chairman of NACA. After due consideration, the Hunsaker committee came out with recommendations for a 10-year Unitary Plan Program of facility construction. The Plan was approved by NACA in January 1947.
The building program that had been organized by the Hunsaker committee and approved by NACA involved two new research and development centers-one for NACA and one for the Air Force-and 33 new wind-tunnel facilities, of which 14, costing $5 million, were to go to universities. The total cost was over $1 billion. The plan contemplated, among other things, a 40-foot transonic propulsion tunnel requiring 530,000 horsepower and costing over $171 million; a 15- by 15-foot supersonic propulsion tunnel requiring 657,000 horsepower and costing over $50 million; a 6- by 6-foot or an 8-by 8-foot hypersonic (M up to 10.0) tunnel pressurized to as much as 100 atmospheres, requiring 410,000 horsepower and costing at least $110 million. One of the intended tunnels would cost half again as much as the value of all of the research facilities at all three of the existing NACA laboratories.
The proposed Unitary Plan was now turned over to the Joint Research and Development Board, who reduced it to a 5-year plan costing "only" $600 million. In the course of the next year, it was reviewed by a number of groups and in 1949, in much curtailed form, appeared in an authorization bill jointly submitted by NACA and the military. This bill, which was passed on October 27, 1949, was divided into two parts, Title I and Title II. Title I authorized expenditures of up to $10 million for university facilities and $136 million for new NACA wind tunnels. Title II authorized the construction of a new air engineering development center for the Air Force which was to include among its facilities two Unitary Plan tunnels.
When the authorization bill had gone through, more specific planning got under way. Many meetings of NACA special panels and committees were held to determine characteristics and priorities of facilities that would be built for NACA and the universities. A prototype university facility was actually built at Langley. The money allocated to NACA, it was felt, would [152] be sufficient to build one major wind tunnel at each of the Committee's three laboratories. To deal further with design matters, Dr. Dryden on December 19, 1949, established an NACA Project Office for the Unitary Wind Tunnel Programs and appointed John F. Parsons as chief. In his new capacity, Parsons was to report directly to Dryden.
It was not until spring of the following year that the Unitary Plan legislation came up for consideration before the congressional appropriations committees. It had been expected that Unitary Plan appropriations might be spread over 2 or 3 years; but Albert Thomas, chairman of the House subcommittee, told NACA in effect, "We'll give you $75 million now and don't come back for any more." And this was the way that, on June 29, 1950, the bill became law. NACA got $75 million for Unitary Plan facilities and the universities got nothing. NACA people were a bit let down. After soaring to rare empyrean heights, they were now back at sea level. But $75 million was not to be sneezed at. It was not much less than the combined value of existing research facilities in all three NACA Laboratories. The Air Force had done considerably better than NACA in Unitary Plan acquisitions. The Air Force had obtained a new research center (AEDC) which it shortly was to name for General Hap Arnold, who deserved the honor for he had really started the whole thing.
1 See David 0. Woodbury, The Glass Giant of Palomar. New
York: Dodd, Mead & Co., 1941.
2 Telemeter (Radio Data Recorder) described in Memorandum (dated Jan. 24, 1942) from Edwin P. Hartman to NACA Coordinator of Research, covering a visit to Vultee Aircraft, Inc., on Jan. 8, 1942.
