The CFM International CFM56 is a turbofan family used on commercial airliners and military aircraft. CFM International is a joint company owned equally by GE Aerospace and Safran Aircraft Engines. The engine's many versions serve different aircraft generations, so the suffix is essential when identifying a particular installation.[1][2]
Earlier applications
The CFM56-2 powered the DC-8 Super 70 re-engining programme and military aircraft including the KC-135R, E-3 and E-6B. These uses illustrate a major part of the family's history: fitting newer propulsion technology to aircraft derived from established airframe designs.[2]
The CFM56-3 powered the Boeing 737 Classic generation. CFM identifies that programme as the start of its exclusive engine relationship with Boeing's successive 737 generations. The later 737 Next Generation used a different CFM56 branch, while the 737 MAX moved to the LEAP family; these names are not interchangeable.[2]
Airbus branches
The Airbus-related CFM56 branches include the -5A, -5B and -5C. The -5B powers members of the A320ceo family, while the -5C is associated with the four-engine A340-200 and A340-300. Different applications required different thrust and installation characteristics, even though the engines retained their common family designation.[2][3]
Final production generations
CFM describes the CFM56-5B and -7B as the family's final production models. The -5B was offered across the four A320ceo-family sizes, whereas the -7B was the exclusive engine for the Boeing 737 Next Generation and its military derivatives. The former aircraft family had competing engine choices, while the latter had an exclusive CFM installation.[3]
The two branches should therefore be compared through their aircraft roles as well as their ratings. Describing an engine only as a CFM56 does not establish whether it fits an Airbus or Boeing aircraft, and sharing the family name does not make the complete engines interchangeable between those installations.[3]
Continuing support
CFM's business includes support for the CFM56 fleet alongside production and support of the newer LEAP family. This separates the end of a particular aircraft-production generation from the end of an engine's operational life. Maintenance, repairs and replacement hardware remain significant parts of a mature propulsion programme after newer engines appear on newly designed aircraft.[1]