By the mid-1930s the wind tunnels of NACA had helped transform the "wire-and-rag" biplanes that fought the War to End Wars into all-metal, low-wing monoplanes. The sleek Douglas DC-3 was already flying passengers coast to coast. The first U.S. Flying Fortresses were aloft, and Supermarine Spitfires streaked peacefully across the skies above England. Progress in the air had been rapid, but for the second time war threatened to scrap reasonable timetables of development.
It was the pre-World War I situation all over again. European countries, feeling the tension growing as the Nazis marshalled German resources, began to pour more and more money into aeronautical research. American aeronautical leaders realized that the acceleration of foreign research was seriously eroding this country's leadership. The superb NACA wind tunnel facilities were no longer the biggest and the best. America was not building supersonic wind tunnels and testing turbojet and rocket engines like the Europeans. The easy answer was that the country was just pulling out of the Great Depression and was preoccupied with economics rather than far-away European war jitters.
Nevertheless, the widening gaps in aeronautical research were recognized in report after report. In October 1938 NACA urged the construction of a whole new aeronautical laboratory at Sunnyvale, California, as well as the expansion of the Langley facilities. To justify its recommendations, NACA pointed out that Germany had multiplied its aeronautical facilities tenfold and boasted five research centers to America's one. Italy had even built an entire city, Guidonia, devoted exclusively to aeronautical research. In late 1938 even an isolationist Congress saw another European war on the horizon.
Just days before the Nazi invasion of Poland, Congress authorized the new Sunnyvale facility. On December 20, 1940, NACA quietly broke ground for the new laboratory at Moffett Field, California. (This facility is now the Ames Research Center of NASA.)
Langley expanded too by opening up a whole new West Area and staking out a site for a new 16-foot high-speed wind tunnel, a stability tunnel, and other research facilities in November 1940.
As the European conflict intensified, a special NACA committee, headed by Charles A. Lindbergh, was appointed to see if the United States was doing enough in aeronautics. It was not, according to the report issued by Lindbergh and his committee. American facilities for aircraft engine research "are inadequate," stated the report. Prewar reluctance to spend funds on research had evaporated, and by mid-1940 Congress had authorized a NACA Flight Propulsion Laboratory to be built near the Cleveland Municipal Airport. Like the Langley and Ames sites, it would also require new wind tunnels, but of radically different design, as befitted its different mission.
The expansion of NACA research came none too soon. Germany flew its first turbojet aircraft on August 27, 1939. Both Great Britain and Germany had operational jet fighters by the end of the war. America did not, but it was close behind. Germany also led the way with the pulse-jet V-1 and the rocket-powered V-2 ballistic missile, technologies the Allies had ignored. Actually, all the new (though belated) NACA facilities were employed during the war, but less for radical innovation than for perfecting huge fleets of high-performance fighters and bombers. In the long run, the immense fleets of more conventional weapons made all the difference in the victory.