This was the only known airborne reactor experiment by the U.S. with an operational nuclear reactor on board. The NB-36H was scrapped at Fort Worth in 1958 when the Nuclear Aircraft Program was abandoned. After the ASTR was removed from the NB-36H, it was moved to the National Aircraft Research Facility. Based on the results of the NTA, the X-6 and the entire nuclear aircraft program was abandoned in 1961. Development plans Had the program progressed, follow-on aircraft would have been based on the successor to the B-36, Convair's swept-wing B-60. The X-6 would have been powered by General Electric X-39 engines (J47 engines modified to use nuclear energy as fuel), utilizing a P-1 reactor. In a nuclear jet engine, the reactor core was used as a heat source for the turbine's air flow, instead of burning jet fuel. One disadvantage of the design was that, since the airflow through the engine was used to cool the reactor, this airflow had to be maintained even after the aircraft had landed and parked. GE built two prototype engines, which can be seen outside the Experimental Breeder Reactor I in Arco, Idaho. A large, wide hangar was built at Test Area North, part of the National Reactor Testing Station (now part of the Idaho National Laboratory; Monteview) to house the X-6 project, but the project was canceled before the planned runway was built, necessitated by the expected weight of the nuclear-powered aircraft. Soviet program In the 1960s, the Soviet Union's Tupolev design bureau had its own design for an experimental nuclear-powered aircraft, the Tupolev Tu-119, which was a Tu-95 bomber with two of its conventional turboprops replaced by nuclear-powered turboprops. Specifications See also References External links Dream of Atomic-Powered Flight original published on Aviation History, March 1995. Joe Baugher. B-36 Peacemaker. Section devoted to NB-36H X-006 Cancelled military aircraft projects of the United States X-06, Convair Nuclear-powered aircraft Six-engined pusher aircraft Aircraft with auxiliary jet engines High-wing aircraft X-6