Republic Aviation Corporation built P-84 Thunderjets in the 1940s. The Thunderjets were the last of the subsonic straight-wing fighter-bombers to see operational service. It was the aircraft with which flight-refueling techniques for fighters was 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).
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 designations of this aircraft, both swept wings; the YF-84F having the inlet in the nose and the YRF-84F having the nose area elongated for cameras then faired, moving the inlets into the sides of fuselage just ahead of the wings with two fences installed on each wing for improved airflow. The "R" stood for reconnaissance. The YRF-84F was flown on research missions, chase for other research flights and for pilot proficiency.
The YF-84A (NACA #134) was used for research studies, pilot proficiency flights, and chase for other research flights while the YF-84A (45-59488) supplied the spare parts for for #134 to remain flying.
