tric. At Arnold's insistence, there were no representatives from the reciprocating aircraft-engine industry, because he feared they would oppose any radical new departures in engine development; later it was claimed that they were excluded because their "energies" were judged to be "completely absorbed in production problems." After meeting seven times in the course of five months, Durand's committee recommended that the services let contracts for three types of jet engine development-one to Allis Chalmers, one to Westinghouse, and one to General Electric. Progressives of 1915 might have blushed at the conflict of interest here, but Durand's committee was never intended to be either democratic or egalitarian. It was intended to get the United States back in the race for aircraft engine supremacy. The way to do that was to bring in the best industrial representatives available, review their research, and support the most promising ones. Not surprisingly, the Main Committee decided that the projects of all the companies represented on the special committee were worthy of support. The military services, who were of course also represented, took the committee's recommendation and awarded development contracts to the three firms.39

The NACA had gone a long way toward rescuing the situation and reestablishing its credibility as the central agency for coordinating American aeronautical research. But it did not stop there. It also recommended that its own project for jet propulsion, under the direction of Eastman Jacobs's at the Langley laboratory, should receive full support and early trials. Jacobs's scheme was a variation on the Campini ducted fan which used a traditional reciprocating engine to drive a fan within a duct behind the engine. To get spurts of additional thrust for combat, fuel could be burned in the duct behind the fan, adding jet propulsion to the conventional thrust. At the time the Durand committee met in 1941, Jacobs had not solved the problem of stable combustion in the afterburner, but the Main Committee nonetheless recommended support. Though Jacobs would make considerable progress over the next two years, he never succeeded in developing an engine as appealing to the military services as the turbine engines developed by the commercial manufacturers. In 1943 the services turned down a request by the Committee to construct an airplane incorporating the Jacobs engine, and there the project died. Jacobs and some other staffers at Langley felt the services were wrong to ignore what Jacobs called a "conservative straightforward engineering design"; but what the services felt they needed-rightly, as it turned out-was a radical new design to help the Americans catch up with England and perhaps Gerinany.40

After the original recommendations of the Durand committee, the NACA's wartime efforts in this field, as in most others in American aeronautics, were limited to coordinating and testing. Significantly and ominously, the NACA was kept in the dark about much that was happening in jet-engine development. When the services brought a Whittle engine to the United States and assigned General Electric the task of building a similar engine, entirely apart from the development contract that company already had on NACA recommendation, the NACA was not told, in keeping, it seems, with a general promise of secrecy made by Arnold to the British. Only through rumor did it learn of the jet-propelled airplane being developed by Bell Aircraft under contract to the services. When Warner wrote from England in 1943 that the British were supplying the United States with all the jetpropulsion information they had, Hunsaker suggested in reply the extent to which the NACA had been reduced from its traditional role: "The idea that they [the British] are supplying 'us' everything they have does not apply to NACA but may apply to the services. The details of this situation are somewhat sticky but I can give you the story orally." Part of the story was simply that the services had put an unprecedented lid of secrecy on all jet-propulsion development. Not only did this policy shut out the NACA more completely than ever

before from developments in military aviation, but it also prevented the manufacturers from freely exchanging information on their projects. In fact, the two sections of the General Electric Company working on the separate jet projects did not know that the other team existed, though of course rumors flew at a great rate. The "Buck Rogers" project for a jet airplane at Bell Aircraft was apparently unknown to some of the employees there. The full story of American jet development during the war has never been made public, but enough is known to suggest that it is a case history in the hazards of excessive secrecy.41

This general cloak of secrecy, however, does not fully explain the extent to which the Committee was excluded from its normally close and candid collaboration with the military services, as Hunsaker's letter to Warner suggests. What had really happened was the onset of a crisis of confidence, a suspicion on the part of the services that the NACA had let them down. Military men understood that they themselves were ultimately responsible for the state of military unpreparedness in which they found themselves. Depending on the NACA to tell them what was important had lulled them into a comfortable laxness in which they had left their own flanks unguarded. Now they were second-best in an important new technology, and they felt that their past reliance on the NACA had been a mistake. So they took to running this new technology by themselves, relying on their own judgment, their own sources of information. Since they wanted to keep the whole field as secret as possible, there was no reason to inform the NACA. The Committee had no "need to know"; keeping the NACA abreast of developments would serve only to multiply potential leaks of information without getting any assistance or advice in return, for the services expected

none.

None of this was explicit. There were no confrontations, no exchanges of acrimony, no pointing of fingers. Outwardly all went on as before, and the written record remained as polite, cordial, and sterile as ever. But beneath the surface and between the lines was a cooling of attachments and a keeping of distances such as the NACA had never known. When Jerome Hunsaker sent General Arnold a paper on "Aeronautical Research" in September 1942, he received in return the suggestion that he concern himself less with the possibility of "frozen designs" in American aircraft production and more with developing better aircraft engines for fighters. "I do not feel that progress made in the improvements of engines is keeping pace with that of the airplane," wrote Arnold. Hunsaker derived from this letter the "impression that there is a feeling that American engine development has been outdistanced by that of foreign powers," and he asked for a meeting with the chief of the Army Materiel Command to clarify the army's position. He was told that the army expected to fight out the war with the aircraft

engines then in production (a reason given then and later by both the army and the NACA for delay in developing jet propulsion). The Committee should therefore occupy itself with refining the engines already in production, a role that effectively barred the NACA from the jet-propulsion development being pursued by the army. The Committee did become involved in testing such jet engines as reached prototype stage; but, when it attempted in the winter of 1942-1943 to penetrate army long-term councils, it was politely advised to stick to conventional engines. 42

General H.H. Arnold inspects the kind of work he wanted the NACA to do during World War II: a researcher at the Aircraft Engine Research Laboratory points out ice buildup on a conventional propeller blade during the general's tour of the laboratory 9 November 1944. George Lewis and John Victory look on at left. (LeRC)

Sensing this new situation without ever being candidly apprised of it, the NACA tried to cut its losses by doing for jet propulsion what it was best at doing. It had been working on compressor design for years in connection with turbosuperchargers. The principles and problems in both fields were almost identical and the NACA could transfer its expertise to the newer field, as indeed it did. Furthermore, the Com

mittee could use its new laboratory at Cleveland for some of the testing required once the new engines reached prototype stage. Although the Cleveland laboratory had not been designed for research in jet propulsion, some of its equipment was suitable for testing both conventional and jet engines, and the Committee quickly sought appropriations for new equipment specifically suited to jet development.43

Improved design of centrifugal superchargers during World War II led to significant increases in efficiency. (LeRC)

And Eastman Jacobs, stung and dissatisfied with the services' rejection of his ducted-fan proposal, began a line of argument that he maintained through the war and into the era of practical jet aviation: too much emphasis was being put on engine development and not enough on the means of fitting these new engines to aircraft. The engine and the airframe must be matched to each other, he maintained, or the efficiency of both would be compromised. Essentially he was arguing for more attention to the aerodynamics of jet engines, and aerodynamics was the NACA's forte, a way for the Committee to make a real contribution to jet-aircraft development even if it was largely excluded from development of the engines.44

LOOKING BEYOND THE WAR

The NACA's failure to discover and develop jet propulsion should not be allowed to mask its real and significant contributions to American aerial victory in World War II. Though air power was not the sole,