This NASA special publication presents a general overview of the flight research that has been conducted at Ames Research Center over the last 57 years. Icing research, transonic model testing, aerodynamics, variable stability aircraft, boundary layer control, short takeoff and landing (STOL), vertical/ short takeoff and landing (V/STOL) and rotorcraft research are among the major topics of interest discussed. Flying qualities, stability and control, performance evaluations, gunsight tracking and guidance and control displays research are also presented. An epilogue is included which presents the significant contributions that came about as a result of research and development conducted at Ames. Flight research has been an integral and essential part of the missions of, first, the National Advisory Committee for Aeronautics (NACA) and, later, its successor, the National Aeronautics and Space Administration (NASA). The NACA's Ames Aeronautical Laboratory was established at Moffett Field, California, in 1939. In its role as an aeronautical research laboratory, Ames, from its inception, made the most of the linkage between exploratory and developmental testing in its wind tunnels and in flight. The research carried out in flight had numerous technical areas of emphasis over the years, and most of the individual experiments can be categorized accordingly. These areas are identified in the narrative to follow as icing research; transonic model testing; aerodynamics research; flying qualities, stability and control, and performance evaluation; variable stability aircraft; gunsight tracking and guidance and control displays; in-flight thrust reversing and steep approach research; boundary-layer control research; short takeoff and landing (STOL) and vertical and short takeoff and landing (V/STOL) aircraft research; and rotorcraft research. From the earliest days of Ames Aeronautical Laboratory until the creation of NASA, the focus of flight research was on military aircraft and their operations. Icing research and the earliest efforts in aerodynamics and flying qualities research occurred during World War II and were intended to aid in the design and operation of aircraft for the Army Air Corps and the Navy. From the war's end until the late 1950s, motivation for research came from the need to achieve ever higher performance and to advance the technology in wing aerodynamics. Upon the transition from the NACA to NASA, headquarters assigned Ames the responsibility for powered-lift research, including flight research with STOL and V/STOL aircraft. This decision was influenced by Ames' broad technical background with this category of aircraft in aerodynamics, performance, stability and control, flying qualities, and operations and because of the presence of the 40- by 80-foot wind tunnel and its experienced aerodynamics staff that had developed considerable expertise in powered-lift technology. Another influence on this decision was the interest the U.S. Army had expressed in this area of technology and the beginnings of what would become a cooperative program in aeronautical research with Ames. Thus, powered-lift research grew into a major effort that has lasted to the present day, supporting military along with newly emerging civil needs. It included the development and flight of several proof-of-concept aircraft, particularly the XV-15 tilt rotor, which stands as one of Ames' most important contributions to aeronautical technology. Further, it was soon to be augmented with rotorcraft flight research when NASA chose to consolidate rotary-wing technology efforts at Ames in the late 1970s. This research was supported and strongly influenced by the Army through its research laboratory, which had been established and collocated at Ames in the late 1960s. This collaborative program continues to this day.