This photo shows a Republic Aviation Corporation YRF-84F Thunderstreak (51-1828 -- NACA tail number 154) on the ramp at the NACA High-Speed Flight Research Station in 1954. Early in 1952 Republic developed a reconnaissance version of the YF-84F Thunderstreak but built only one of them. The nose was elongated to take the camera equipment and faired in. The intakes were relocated from the nose to the wing-root, retaining the swept wing, but with fences added for improved airflow. The canopy was retained from the old Thunderjet-type, YF-84A. The NACA High-Speed Flight Research Station obtained this aircraft in 1954, using it for pilot proficiency flights until 1955.

Republic Aviation Corporation, Long Island, New York, built P-84 Thunderjets in the 1940s. The Thunderjets were the last of the subsonic straight-wing fighter-bombers to see operational service. They were the aircraft with which flight-refueling techniques for fighters were developed. The first fifteen P-84 production aircraft were fitted with Allison J35A-15 engines and designated YF-84As. (Note: In 1948 aircraft belonging to the newly independent United States Air Force went through a change in designation for the new production aircraft. The P [pursuit] became F [fighter] with the Y indicating service test of a prototype aircraft.)

The NACA High-Speed Flight Research Station (later redesignated the NASA Dryden Flight Research Center after the National Aeronautics and Space Administration was formed from the older National Advisory Committee for Aeronautics) acquired two YF-84A Thunderjets; YF-84A (45-59490), which was given the NACA tail number 134, transferred from Langley Aeronautical Laboratory, Hampton, Virginia, in November 1949, and YF-84A (45-59488) transferred from Ames Aeronautical Laboratory, Mountain View, California, in December 1950.

The YF-84A (NACA number 134) was used for research studies, pilot proficiency flights, and as chase for other research flights while the remaining YF-84A (45-59488) supplied the spare parts for number 134 to remain flying. The YF-84As had straight wings with a nose inlet for air intake into the engine.

Flight tests using the YF-84F Thunderstreak (49-2430), on loan from the Air Force, studied the aileron effectiveness of the aircraft before spoilers were incorporated. There were two versions of this aircraft, both with swept wings. The YF-84F had the inlet in the nose. On the YRF-84F the nose area was elongated, to accommodate cameras, then faired. This configuration moved the inlets into the sides of the fuselage just ahead of the wings, with two fences installed on each wing for improved airflow. The R in this designation stood for reconnaissance.

The YRF-84F (51-1828) was the only aircraft built with this designation. It came to the High-Speed Flight Research Station in April 1954, bore the NACA tail number of 154, and departed in October 1956. It was flown on research missions, as chase for other research flights, and for pilot proficiency.