Editing General Electric CF6 (section)

===CF6-50===

The CF6-50 series are high-bypass turbofan engines rated between 51,000 and 54,000&nbsp;lb (227.41 to 240.79&nbsp;kN, or '25 tons') of thrust. The CF6-50 was developed into the LM5000 industrial [[turboshaft]] engines. It was launched in [[1969 in aviation|1969]] to power the long range McDonnell Douglas [[McDonnell Douglas DC-10|DC-10-30]], and was derived from the earlier CF6-6.

Not long after the -6 entered service, an increase in thrust was required. It was obtained by increasing the mass flow through the core. Two booster stages were added to the LP (low pressure) compressor and the last two stages of the HP compressor were removed<ref>"CF6 Reliability", Flight International,2 July 1977, p. 11</ref> which increased the overall pressure ratio to 29.3. Although the 86.4 in (2.19 m) diameter fan was retained, the airflow was raised to 1,450&nbsp;lb/s (660&nbsp;kg/s), yielding a static thrust of 51,000&nbsp;lb<sub>f</sub> (227&nbsp;kN). The increase in core flow decreased the bypass ratio to 4.26.

In late 1969, the CF6-50 was selected to power the then new [[Airbus A300]]. [[Air France]] became the launch customer for the A300 by ordering six aircraft in [[1971 in aviation|1971]]. In [[1975 in aviation|1975]], [[KLM]] became the first airline to order the [[Boeing 747]] powered by the CF6-50. This led further developments to the CF6 family such as the CF6-80. The CF6-50 also powered the [[Boeing YC-14]] USAF AMST transport prototype.

The basic CF6-50 engine was also offered with a 10% thrust derate for the 747SR, a short-range high-cycle version used by All Nippon Airways for domestic Japanese operations. This engine is termed the CF6-45.

The engine is designated the General Electric F103 in [[United States Air Force]] service on [[McDonnell Douglas KC-10 Extender|KC-10 Extenders]] and [[Boeing E-4]]s.