The Pratt & Whitney J75 was developed between 1951 and 1954 to meet the needs of advanced supersonic fighters under development for the U.S. Air Force and Navy. Its configuration and control, fuel and lubrication systems are similar to those of the smaller J57. The larger J75 incorporated many mechanical and aerodynamic improvements.
The military version with afterburner powered the Convair 106 interceptor and the Republic F105 Thunderchief fighter-bomber. This artifact is installed in the museum's F105, which served in Viet Nam. The commercial version of the J75 was certificated in 1957 and powered several long-range versions of the Boeing 707 and Douglas DC-8 airliners.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.