The test aircraft ran from the exotic, such as the Wilford XOZ-1 Gyroplane, through standard military aircraft such as the Boeing XB-15 and B-17. Test pilots were often assigned to fly particular types of aircraft because of their past experience, although there was a great deal of latitude in this. McAvoy, who had successfully tested the Grumman XF3F-1 after two civilian pilots had been killed in it, flew everything from fighters to the four-engine Hall Aluminum flying boat. Reeder specialized in rotary-wing aircraft, but also flew standard military aircraft such as the Republic P-47 or North American P-51. In his 42-year career, Reeder flew more than 230 different types of aircraft, including advanced swept-wing jets.

The NACA regularly released photos of experimental aircraft suspended for tests in the famous Full-Scale Tunnel (FST). The results of these tests often resulted in subtle changes to the airframes that increased performance and safety. The FST enabled engineers to make quick changes, and retest the aircraft to validate the results. Oftentimes the changes resulted from the combination of scientific, engineering, and flight experience that characterized NACA actions.

Jones foresaw the advantages of a swept-back wing for high-speed flight. Unfortunately, his idea didn’t meet with full acceptance at NACA.

A similar approach was used in the revolutionary process by which NACA engineers, inspired by John Stack, approached the problem of converting two “standard” wind tunnels (the 8-foot and the 16-foot high speed) to testing at supersonic speeds. Doubling the tunnel’s horsepower had not achieved the necessary margin. A sustained effort by John Becker, Eugene C. Draley, Coleman duPont Donaldson, a young man named Richard Whitcomb, and others created a totally new “slotted throat” approach to avoiding “choking” in the tunnels. In a painful and protracted step-by-step process, small models were introduced with new mounting techniques and with both major and minor interior changes to the tunnel walls that ultimately made testing at supersonic speeds possible.

While World War II crowded Langley with new American and foreign types, there was some criticism of the NACA’s failure to anticipate the need for a supersonic wind tunnel. NACA engineer Robert Gilruth backed tests in which models were mounted on the wings of a P-51, which then dove to a speed of Mach .75. Another approach was the far-seeing – but ignored – research of Robert T. Jones, a student of Max Munk and an expert on stability and control. Jones foresaw the advantages of a swept-back wing for high-speed flight. Unfortunately, his idea didn’t meet with full acceptance at NACA.

For many of the engineers, scientists, and test pilots, the change was in name only, for they continued their routines as in the past, eagerly greeting each new advance in aviation as NACA had done for 43 years.

Nonetheless, NACA embraced the jet age, with the famous Stack leading the design experiments that ultimately permitted the aerodynamic testing of the Bell X-1 in the NACA wind tunnels. (Stack, working with the NACA veteran Jean Roché and then-Maj. Ezra Kotcher, USAAF, paved the way at NACA for testing rocket-powered aircraft). After Chuck Yeager’s seminal flight on Oct. 14, 1947, NACA test pilot Herbert Hoover became the first civilian to fly faster than the speed of sound. Another NACA star, Robert Champine, also went supersonic in the X-1, and then conducted tests on two Douglas test planes designed by the great Ed Heinemann, the D-558-1 Skystreak and its follow-on D-558-2 Skyrocket.

Perhaps the most well-known NACA contribution in the postwar jet age was Whitcomb’s famous “area rule,” first applied to a Grumman F11F-4 Tiger. It was then used to salvage the Convair YF-102 design, for which Whitcomb received the Collier Trophy in 1954. Later in his career, Whitcomb was noted for the development of the supercritical airfoil in the 1960s, and a decade later, for the development of the now nearly universal “winglet” as drag reduction devices. (It should be mentioned that drawings in Roché’s notebook of the early 1930s show similar winglets, intended for exactly the same purpose.)

With the advent of the “Space Age,” highlighted by the 1957 launch of the Sputnik satellite by the Soviet Union, NACA became the obvious organization to take up space research. President Dwight D. Eisenhower signed the National Aeronautics and Space Act in July 1958, and on Oct. 1, 1958, the new NASA took over the NACA, including its three major research laboratories (Langley Aeronautical Laboratory, Ames Aeronautical Laboratory, and Lewis Flight Propulsion Laboratory), along with 8,000 employees, its $100 million budget, and dozens of small test facilities. For many of the engineers, scientists, and test pilots, the change was in name only, for they continued their routines as in the past, eagerly greeting each new advance in aviation as NACA had done for 43 years.