The NACA was the National Advisory Committee for Aeronautics, a predecessor of the National Aeronautics and Space Administration (NASA). The HSFRS was a predecessor of NASA’s Dryden Flight Research Center, and Langley Aeronautical Laboratory became NASA’s Langley Research Center.
The P-51D was the first aircraft to employ the NACA laminar-flow airfoil design and could dive to a speed of roughly Mach 0.8. As an F-51 Fighter, instead of a P-51D pursuit aircraft, the aircraft was used as a proficiency aircraft at HSFRS. Records show that the aircraft was also used as a chase and support aircraft 395 times. Neil Armstrong was among the pilots using it to chase some of the X-planes (that is, provide safety support). The P-51D was retired in 1959 as the result of a taxiing mishap.