In the 1940s, NACA was a research and development organization, devoted to cutting-edge aeronautical research. At the Langley Research Center, advanced wind tunnels were used to test new aircraft designs, and studies were taking place on new concepts such as the X-1 rocket plane.[8] Kraft was assigned to the flight research division, where Gilruth was then head of research. His work with NACA included the development of an early example of gust alleviation system for an aircraft flying in turbulent air.