The first engine entering the test program reached and sustained 33,000 lbf (150 kN) of thrust, required to satisfy the highest rating for the Airbus A321neo. In total, 28 test engines will be used by CFM to achieve engine certification, and 32 others will be used by Airbus, Boeing and COMAC for aircraft certification and test programs. The aircraft was due to begin testing in 2016. In 2009, COMAC selected the LEAP engine for the C919. It is intended to be a successor to the CFM56-5B and CFM56-7B.
The engine was officially launched as LEAP-X on 13 July 2008. The LEAP ("Leading Edge Aviation Propulsion") incorporates technologies that CFM developed as part of the LEAP56 technology acquisition program, which CFM launched in 2005. The LEAP-1A was tested on GE's 747-400 flying test platform. According to Aviation Week's article, "The eductor device produces a venturi effect, which ensures a positive pressure to keep oil in the lower internal sump." The engine has some of the first FAA-approved 3D-printed components. Reliability is also supported by use of an eductor-based oil cooling system similar to that of the GEnx, featuring coolers mounted on the inner lining of the fan duct. These technological advances are projected to produce 16% lower fuel consumption. GE is using ceramic matrix composites (CMC) to build the turbine shrouds. Currently proposed for the LEAP is a greater use of composite materials, a blisk fan in the compressor, a second-generation Twin Annular Pre-mixing Swirler (TAPS II) combustor, and a bypass ratio around 10-11:1.
While the LEAP is designed to operate at a higher pressure than the CFM56 (which is partly why it is more efficient), GE plans to set the operating pressure lower than the maximum to maximize the engine's service life and reliability. The fan has flexible blades manufactured by a resin transfer molding process, which are designed to untwist as the fan's rotational speed increases. The LEAP's basic architecture includes a scaled-down version of Safran's low pressure turbine used on the GEnx engine.
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