I have often wondered just what research took place at the National Advisory Committee for Aeronautics (NACA) during World War II in relation to “drag clean-up.” John F. Victory, NACA’s secretary boasted in 1942 that “The employees of the NACA have a big and important job to do. They are at war with similar research organizations in Germany, Japan, and Italy. It is their responsibility and they are using their technical knowledge and skill to make sure that the airplanes that are given to American and allied flyers are better and more efficient instruments of war than those flown by enemy airmen.”
While those efforts resulted in a number of important developments one that the NACA emphasized was its efforts to create cleaner aerodynamic fuselage designs and wing configurations to increase the speeds of fighter aircraft.
The NACA’s many wind tunnels were employed with direct benefit in this endeavor. Old NACA hands liked to recall how the Committee had been approached by Hap Arnold in June 1939 asking for a 400 mph fighter that could go head-to-head with and beat the best German aircraft. He spoke at length with NACA director of research George W. Lewis about this requirement and Lewis promised that the NACA could give the Army a plane with a 400 mph top speed.
The Bell P-39 had been designed as a 400 mph fighter but it had been unable to attain that level of performance, although a stripped down prototype had flown as fast as 390 mph at Wright Field, Ohio. During the summer of 1939 engineers at Langley investigated ways to eliminate drag on the aircraft and increase its speed. They used the full-scale wind tunnel to test various configurations and eventually came up with several modifications which pointed toward 400 mph flight under optimum conditions. In reality, the NACA engineers increased the speed of the P-39 by about 16 percent, but because of the weight of production models it never did fight or even fly at 400 mph.
A more successful aerodynamics effort was the development of low-drag wings for the P-51 “Mustang,” the “Cadillac of the Skies,” which helped it to be one of the great fighters of World War II.
During the war Langley performed such research for 23 aircraft in production for the military. The drag cleanup it achieved provided the edge that Arnold had wanted for his fighter pilots. A 10 percent increase in performance was often enough to outrun or outmaneuver an enemy in a dogfight.
No doubt, this was a significant aspect of the NACA’s wartime role in applied research. I would like to know more about those efforts through a more detailed study in the future.