The TF39 was developed to power the Lockheed C-5A Galaxy, the largest aircraft in the US Air Force fleet. The high-bypass turbofan was a giant leap in aircraft engine design, offering high thrust levels (41,100 pounds) and revolutionary fuel efficiency. The TF39 was the first high-power, high-bypass jet engine available and included such pioneering technological accomplishments as an 8-to-1 bypass ratio, 25-to-1 compressor pressure ratio, a 2,500°F turbine temperature made possible by advanced cooling techniques, and a GE-designed thrust reverser. The engine's fan, compressor, combustor, turbine, and exhaust systems were almost perfectly matched, and each system was significantly more efficient than its predecessors.
GE Aviation was awarded the contract by the US Air Force to develop the TF39 in 1965. The first engine went to test the same year. Between 1968 and 1971, 463 TF39-1 and -1A engines were produced and delivered to power the C-5A fleet. In December 1982 the Air Force contracted with Lockheed Martin to provide an additional 50 C-5B aircraft. In February 1983, Lockheed Martin sub-contracted with GE for delivery of 200 TF39-1C (43,000 pounds thrust) engines and thrust reversers. Initial delivery of the first TF39-1C engine occurred in January 1985 and the 200th engine shipped in November 1988.
The TF39 became the parent of GE's highly successful CF6 family of commercial engines for wide-body aircraft. In addition, it has gone to sea in the form of the derivative LM2500 Marine and Industrial engine. Since introduction, the TF39 has benefited directly from CF6 design technology -- components, materials, processes, manufacturing techniques, and repair processes.