The J73 engine was developed by the General Electric Company from the J47 engine in the early 1950s. The more powerful J-73 was used in F-86H aircraft instead of the J47 as in earlier series F-86s. In September 1954, during the National Aircraft Show at Dayton, Ohio, a J73 engine powered an F-86H to a world's speed record of 649.302 mph for a 500-kilometer closed course in the General Electric Trophy Event. At the same show, the J73-powered F-86H also established a Thompson Trophy Event record of 692.818 mph over a 100-kilometer closed course.
The F-86H's high-wing loading and power, deficiencies at high altitudes demoted its role. The J-73 engine generated almost 50 percent more thrust (with only 18 percent more gross weight) but gained little in top speed due to the airframe's Mach limitations. Hence, the F-86H, ordered in 1951 as a fighter bomber, reclassified in 1952 as a primary day fighter, ended up in 1954 as a tactical support fighter-bomber. This did not mark the F-86H--last of the F-86 series as a complete failure. It eventually became a better air-to-ground gunnery platform than the F-86F, with faster climb and acceleration rates. Meanwhile, problems of all kinds plagued the aircraft.
The new J73 engines were in short supply and this problem was soon compounded by a lack of spare parts. Logistical support of the J73 became even more difficult following modification of all J73s to the -3A configuration and the subsequent upgrading of all -3As to the -3D final version. In May 1955 General Electric was 224 production engines behind schedule, the Air Force was unable to satisfy projected engine changes, and logistical support of the engines in use remained critical. In the meantime, to make matters worse, F-86H airframes had to be modified before any of the earlier J-73 engines could be replaced by the new J73D.
The Air Force quickly disposed of its F-86Hs in favor of the F-100C--TAC's first level flight, supersonic day fighter. In late 1957 the only F-86Hs still possessed by TAC were assigned to a fighter day unit at Seymour Johnson AFB, N.C., and their transfer to the Air National Guard was completed in June 1958.
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