LEAPTurbofan Engine

LEAP-1A:  24,500 – 32,900 POUNDS THRUST
LEAP-1B:  23,000 – 28,000 POUNDS THRUST
LEAP-1C:  27,980 – 30,000 POUNDS THRUST


The CFM LEAP-1B will be the exclusive powerplant for the Boeing 737 MAX family of single-aisle aircraft (737 MAX-7, 737 MAX-8, 737 MAX-9). This engine has been optimized to provide the 737 MAX the best possible fuel efficiency while maintaining the reliability and maintenance cost legacy of the CFM56 family.


Innovative technologies for tomorrow's engines




Link to LEAP data vis




CFM and its parent companies have fielded more new engines, engine upgrades, new technologies, and have more field experience as measured in engine flight hours than anyone else. Performance and technology is better proven than promised.


Performance advancements are driven by appropriate application of new technology throughout an engine. Success in development of new technology requires the combination of both consistent investment and opportunities for commercial application.

Two engine families have contributed significantly to the design of the LEAP engine, the CFM56 and the GE90/GEnx series of engines. The GE90/GEnx contributed the high-efficiency core architecture to minimize fuel consumption, while the CFM56 legacy drove reliability and maintenance cost design practices. At entry into service in 2017, it is estimated that the GE90/GEnx architecture will have generated 80 million flight hours of revenue service, while the CFM56 family will have over 700 million flight hours of experience. The LEAP engine family offers proven, material advantages over any other engine, with 550,000 hours of proven experience with 99.98% reliability, and 22,000 engines delivered on-time and on-spec.

The CFM LEAP pedigree ensures with confidence the ability to deliver a 15% improvement in fuel efficiency, as compared to the CFM56-7BE, while maintaining the same level of dispatch reliability and life-cycle maintenance costs as the CFM56-7BE. With its simple architecture and $2 billion annual investment in technology, the LEAP engine family offers the lowest cost and highest revenue-generating ability, saving an estimated nearly $3 million per plane.

This is CFM, proven performance, low execution risk, and the application of advanced technology both at entry into service and throughout an engine’s life cycle.


  • Simple, high-efficiency core architecture
  • Up to 15% improvement in fuel efficiency compared to the CFM56-7BE
  • Same high level of dispatch reliability and low life-cycle maintenance costs as the CFM56-7BE
  • 550,000 hours of proven experience with 99.98% reliability


LEAP-1A - Airbus A320neo

LEAP-1B - Boeing 737 MAX

LEAP-1C - Comac C919


Milestone Date Milestone Date
LEAP56 (Leading Edge Aviation Propulsion) begins June 2005 Launch of the LEAP-1C-powered C919 is announced November 2010
LEAP56 (Leading Edge Aviation Propulsion) begins 2007 LEAP engine is selected to power Airbus A320neo December 2010
Initial component and rig tests 2008 Virgin America launches LEAP engine with $1.4 billion order June 2011
Composite fan case containment test, fan aerodynamic and bird strike tests, TAPS combustor and high-pressure compressor rig tests and high- and low-pressure turbine component tests 2008 CFM marks its 1,001st innovation for the LEAP engine June 2011
Component tests on resin transfer molding (RTM) fan blade and the ceramic matrix composite (CMC) high-pressure turbine nozzles July 2008 LEAP fan blade-out rig test is successfully completed June 2011
CFM launches LEAP to power future replacements for current narrow-body aircraft June 2009 Testing validates ultra-high-efficiency LEAP low pressure turbine June 2011
First LEAP core testing begins November 2009 Advanced LEAP fan endurance test complete August 2011
CFM completes eCore demonstrator 1 testing July 2010    


LEAP’s angled high-pressure turbine blade tip squealer generates an aerodynamic vena contracta to reduce leakage and improve turbine efficiency.

LEAP's high-pressure turbine blade counter tip baffle airfoil reduces aerodynamic loss in the turbine and improves engine fuel burn. LEAP's non axi-symmetric airfoil bands and platforms limit secondary flow to reduce pressure loss and improve engine fuel burn.

LEAP's nested ball/roller for core bearing spring finger reduces sump volume and increases engine by-pass ratio.

LEAP's high-pressure compressor airfoil design with rotor radial camber distribution improves compressor stage throttle margin.