| LEAP | |
|---|---|
 | |
.jpg) Mockup of a LEAP-X, the early code name of the engine | |
| Type | Turbofan |
| National origin | France/United States |
| Manufacturer | CFM International |
| First run | 4 September 2013[1] |
| Major applications | |
| Number built | 2,516 (June 2019)[i] |
| Developed from | |
| Developed into | General Electric Passport |
TheCFM International LEAP ("Leading Edge Aviation Propulsion") is ahigh-bypass turbofan engine produced byCFM International, a 50–50joint venture between the AmericanGE Aerospace and the FrenchSafran Aircraft Engines. It competes with thePratt & Whitney PW1000G fornarrow-body aircraft.
The LEAP uses 15% less fuel and produces 15% less CO₂ compared to the CFM56.[6] It uses a scaled-down version of the low-pressure turbine used on theGeneral Electric GEnx engine. The fan blades are made of composite materials using aresin transfer molding process and untwist under aerodynamic and centrifugal loads to maintain aerodynamic efficiency.
Although designed with a higher overall pressure ratio than the CFM56, the engine operating limit is lower to improve durability and service life.[7] It uses a higher proportion of composite materials, features the second-generation Twin Annular Pre-mixing Swirler (TAPS II) combustor, and has a bypass ratio of approximately 10:1 to 11:1. The high-pressure compressor has a pressure ratio of 22:1, approximately double that of the CFM56.[8] The turbine shrouds, made fromceramic matrix composites (CMCs), are lighter than those on the CFM56.[9][10][11]
The LEAP incorporates aneductor-based oil cooling system, derived from the GEnx design. This system includes oil coolers mounted on the fan duct and uses aventuri effect to maintain oil pressure within the internal sump.[7] Additionally, the LEAP includes some of the first FAA-certified3D-printed components used in a commercial jet engine.[12]
The LEAP-1C variant, developed for the Chinese-builtComac C919, reportedly omits some of the advanced technologies found in other LEAP models. According to industry sources, this decision was influenced by concerns that thetechnology could be stolen and put into theCJ-1000A engine being developed by another state-owned manufacturer, theAero Engine Corporation of China. Some analysts have described the LEAP-1C as more closely related in capability to an upgraded CFM56 than to other LEAP variants.[13]
The LEAP[14] incorporates technologies that CFM developed as part of the LEAP56 technology acquisition program, which CFM launched in 2005.[15] The engine was launched asLEAP-X on 13 July 2008,[10] intended as a successor to theCFM56.
In 2009,COMAC selected the LEAP engine for theC919.[16]28 development engines were used by CFM to achieve engine certification, and 32 more used byAirbus,Boeing andCOMAC for aircraft certification and other test programs.[1][17]
CFM carried out the first test flight of a LEAP-1C inVictorville, California, with the engine mounted on the companyBoeing 747 flyingtestbed aircraft on 6 October 2014. The -1C version has a thrust reverser with a one-piece O-Duct replacing the more usual two-piece D-Duct. There are no drag links for the blocker doors giving a smoother flowpath for the fan air.[19]
It obtained its 180-minuteETOPS approval from the U.S.Federal Aviation Administration and theEuropean Aviation Safety Agency on 19 June 2017.[20]
On 20 July 2011,American Airlines announced that it planned to purchase 100 Boeing 737 aircraft featuring the LEAP-1B engine.[21] The project was approved by Boeing on 30 August 2011, as theBoeing 737 MAX.[22][23]Southwest Airlines was the launch customer of the 737 MAX with a firm order of 150 aircraft.[24]
The list price wasUS$14.5 million[25] for a LEAP-1A, andUS$14.5 million for a LEAP-1B.[26]
CFM International were offering rate-per-flight-hour support agreements (also known as "power by the hour" agreements) for the engine. For a LEAP-1A engine, costs were aroundUS$3,039 per engine, per day, compared toUS$1,852 per engine, per day for the prior-generation CFM56.[27]
In 2016, CFM booked 1,801 orders, and the LEAP backlog stood at more than 12,200, worth more thanUS$170 billion at list price.[2]
By July 2018, the LEAP had an eight-year backlog with 16,300 sales. At that time, more LEAPs were produced in the five years it was on sale than CFM56s in 25 years.[3]It is the second-most ordered jet engine behind the 44-year-old CFM56,[28] which achieved 35,500 orders.[3] Also, on the A320neo, where the engine was competing with thePratt & Whitney PW1000G, the LEAP had captured a 59% market share in July 2018. By comparison, the CFM56 had a 60% share of the prior-generationA320ceo market.[28][29]
In 2020, GE Aviation reported that CFM had lost 1,900 orders for LEAP engines worthUS$13.9 billion (US$7.3 million each), reducing the backlog value toUS$259 billion. More than 1,000 cancellations came fromBoeing 737 MAX orders being canceled among theBoeing 737 MAX groundings, while the remainder came from theimpact of the COVID-19 pandemic on aviation.[30]
In May 2025, the United States Department of Commerce paused the export of LEAP engines toCOMAC.[31] The restrictions were lifted in July 2025 amid de-escalating U.S.-China trade tensions, with the U.S. permitting GE Aerospace to restart shipments.[32]
In 2016, the engine was introduced in August on theAirbus A320neo withPegasus Airlines and CFM delivered 77 LEAP.[2] With the737 MAX introduction, CFM delivered 257 LEAPs in the first three quarters of 2017, including 110 in the third: 49 to Airbus and 61 to Boeing, and targets 450 in the year.[33] CFM was to produce 1,200 engines in 2018, 1,900 in 2019, and 2,100 in 2020.[34] This is compared to the 1,700CFM56 produced in 2016.[35]
To cope with the demand, CFM duplicated supply sources on 80% of parts and subdivided assembly sites, already shared between GE and Safran.[36] GE assembles LEAP engines inLafayette, Indiana, in addition to its existingDurham, North Carolina, facility.[36] As more than 75% of the engine comes from suppliers, critical parts suppliers pass “run-rate stress tests” lasting two to 12 weeks.[36]Pratt & Whitney suffered delays in receiving parts to an accelerated schedule on its competingPW1100G geared turbofan, including shortages for its aluminium-titaniumfan blade, which affectedAirbus A320neo andBombardier CSeries deliveries.[36] Safran assembles LEAP engines inVillaroche, France, and Safran and GE each assemble half of the annual volume.[37]
In 2018, 1,118 engines were delivered.[4]
Over the first half of 2019, CFM revenues were up by 23% to€5.9 billion with 1,119 engine deliveries; declining sales of CFM56 (258 sold), more than offset by LEAP (861 sold).[5] Recurringoperating income rose by 34% to€1.2 billion, but was reduced by€107 million (US$118 million) due to the negative margins and initial costs of LEAP production, before a positive contribution expected in the second half.[5] Revenues were expected to grow by 15% in 2019 butfree cash flow depended on the return to service of thegrounded 737 MAX.[5]
In 2019, LEAP production rose to 1,736 engines, and orders and commitments reached 1,968 amid the 737 MAX groundings, compared with 3,211 for 2018, for a stable backlog of 15,614 (compared to 15,620).[38] CFM expected to produce 1,400 LEAP engines in 2020, including an average of 10 weekly LEAP-1Bs for the Boeing 737 Max.[38] By March 2022, CFM intended to output 2,000 engines in 2023, up from 845 deliveries in 2021.[39]In 2023, CFM booked over 2,500 orders, resulting in a backlog of 10,675, delivered 1,570 Leap engines, up by 38% from 1,136 in 2022, and was expecting 20-25% more deliveries for 2024.[40]
The troubled introduction of thePratt & Whitney PW1100G on the A320neo motivated customers to choose LEAP engines. LEAP market share rose from 55% to 60% in 2016, but orders for 1,523 aircraft (29%) had not specified which engine would be chosen.[41] From January through early August 2017, 39 PW1100G engines versus 396 CFM LEAP engines were chosen.[41] By 2024, the LEAP was selected for 75% of the A320neo orders.[40] As an example of PW1100G reliability issues, 9% of LEAP-powered A320neos were out of service for at least one week in July 2017, compared with 46% of those using the PW1100G.[41]
A contract for the production of components for the low-pressure turbine of the LEAP engine was signed on February 12, 2025, between Safran Aircraft Engines and India's Titan Engineering and Automation Limited. Manufacturing will start from 2026.[42] An additional agreement was signed for manufacturing turbine forged parts withHindustan Aeronautics Limited.[43]
The Boeing 737 MAX LEAP-1B started revenue service in May 2017 withMalindo Air with 8 hours of daily operation, while the A320neo LEAP-1A surpassed 10 hours per day by July.
In October 2017, anexhaust gas temperature shift was noticed during a flight and aCMC shroud coating in the high-pressure turbine was seen flaking off in aborescope inspection. This caused more hot gas leakage past the turbine than normal. A design change was required to the coating.[44][33][45][46]
| Model | Application | Thrust range | Introduction |
|---|---|---|---|
| -1A | Airbus A320neo family | 24,500–35,000 lbf (109–156 kN) | 2 August 2016[48] |
| -1B | Boeing 737 MAX | 23,000–29,000 lbf (100–130 kN) | 22 May 2017[49] |
| -1C | Comac C919 | 27,980–30,000 lbf (124.5–133.4 kN) | 28 May 2023[50] |
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| Model | LEAP-1A[51] | LEAP-1B[52] | LEAP-1C[51] |
|---|---|---|---|
| Configuration | Twin-spool,high bypass turbofan | ||
| Compressor | 1 fan, 3-stageLP, 10-stageHP[53] | ||
| Combustor | TAPS II (Twin-Annular, Pre-mixing Swirler second-generation)[47] | ||
| Turbine[54] | 2-stage HP, 7-stage LP | 2-stage HP, 5-stage LP | 2-stage HP, 7-stage LP |
| Overall pressure ratio | 40:1[53] (50:1 at top of climb) | ||
| TSFC at cruise | 0.51 lb/lbf/h (14.4 g/kN/s)[55] | 0.53 lb/lbf/h (15.0 g/kN/s)[55] | 0.51 lb/lbf/h (14.4 g/kN/s)[56] |
| Fan diameter[53] | 78 in (198 cm) | 69.4 in (176 cm) | 77 in (196 cm)[57] |
| Bypass ratio[53] | 11:1 | 9:1 | 11:1 |
| Length | 3.328 m (131.0 in)[a] | 3.147 m (123.9 in) | 4.505 m (177.4 in)[b] |
| Max. width | 2.543 m (100.1 in) | 2.421 m (95.3 in) | 2.659 m (104.7 in) |
| Max. height | 2.362 m (93.0 in) | 2.256 m (88.8 in) | 2.714 m (106.9 in) |
| Max. weight | 3,153 kg (6,951 lb) (Wet) | 2,780 kg (6,130 lb) (Dry) | 3,935 kg (8,675 lb) (Wet) |
| Max. take-offthrust | 143.05 kN (32,160 lbf) | 130.41 kN (29,320 lbf) | 137.14 kN (30,830 lbf) |
| Max. continuous thrust | 140.96 kN (31,690 lbf) | 127.62 kN (28,690 lbf) | 133.22 kN (29,950 lbf) |
| Max.rpm | HP: 19,391 LP: 3,894 | HP: 20,171 LP: 4,586 | HP: 19,391 LP: 3,894 |
| Variant | Take-off | Max. continuous | Application |
|---|---|---|---|
| -1A23 | 106.80 kN (24,010 lbf) | 104.58 kN (23,510 lbf) | N/a |
| -1A24 | 106.80 kN (24,010 lbf) | 106.76 kN (24,000 lbf) | Airbus A319neo (A319-151N),Airbus A320neo (A320-252N) |
| -1A26 | 120.64 kN (27,120 lbf) | 118.68 kN (26,680 lbf) | Airbus A319neo (A319-153N), Airbus A320neo (A320-251N) |
| -1A29 | 130.29 kN (29,290 lbf) | 118.68 kN (26,680 lbf) | Airbus A320neo (A320-253N) |
| -1A30 | 143.05 kN (32,160 lbf) | 140.96 kN (31,690 lbf) | Airbus A321neo (A321-252N), (A321-252NX) |
| -1A32 | 143.05 kN (32,160 lbf) | 140.96 kN (31,690 lbf) | Airbus A321neo (A321-251N), (A321-251NX) |
| -1A32X | 143.05 kN (32,160 lbf) | 110.54 kN (24,850 lbf) | N/a |
| -1A33 | 143.05 kN (32,160 lbf) | 140.96 kN (31,690 lbf) | Airbus A321neo (A321-253N), (A321-253NX) |
| -1A33X | 143.05 kN (32,160 lbf) | 110.54 kN (24,850 lbf) | Airbus A321XLR (A321-253NY) |
| -1A35A | 143.05 kN (32,160 lbf) | 140.96 kN (31,690 lbf) | N/a |
| -1A35AX | 143.05 kN (32,160 lbf) | 110.54 kN (24,850 lbf) | N/a |
| -1B25 | 119.15 kN (26,790 lbf) | 115.47 kN (25,960 lbf) | Boeing 737 MAX 8,737 MAX 8-200 |
| -1B27 | 124.71 kN (28,040 lbf) | 121.31 kN (27,270 lbf) | Boeing 737 MAX 8,737 MAX 8-200 |
| -1B28 | 130.41 kN (29,320 lbf) | 127.62 kN (28,690 lbf) | Boeing 737 MAX 8,737 MAX 8-200,Boeing 737 MAX 9 |
| -1C28 | 129.98 kN (29,220 lbf) | 127.93 kN (28,760 lbf) | Comac C919-100STD |
| -1C30 | 137.14 kN (30,830 lbf) | 133.22 kN (29,950 lbf) | Comac C919-100ER |
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