CFM International LEAP

CFM International
Company type	Joint venture
Industry	Aerospace
Founded	1974; 52 years ago
Founder	GE Aerospace and Safran Aircraft Engines
Headquarters	United States and France
Area served	Worldwide
Products	Aircraft engines (including LEAP series)
Owner	GE Aerospace (50%), Safran Aircraft Engines (50%)
Website	www.cfmaeroengines.com

Template:Infobox Aircraft Engine

The CFM International LEAP (an acronym for "Leading Edge Aviation Propulsion") is a high-bypass turbofan engine manufactured by CFM International, a joint venture equally owned by American firm GE Aerospace and French company Safran Aircraft Engines. Serving as the successor to the extensively utilized CFM56, the LEAP engine directly competes with the Pratt & Whitney PW1000G in powering narrow-body aircraft.

Design

Designed to surpass the fuel efficiency and emissions standards of the CFM56, the LEAP incorporates several advanced features. It utilizes a scaled-down low-pressure turbine derived from the General Electric GEnx, along with fan blades crafted from composite materials produced through a resin transfer molding technique that allows aerodynamic twisting under operational loads.

While capable of operating at higher pressure levels than its predecessor, the LEAP generally runs at reduced pressures to improve reliability and extend maintenance intervals. The engine integrates increased composite content, employs a second-generation Twin Annular Pre-mixing Swirler (TAPS II) combustor, and maintains a bypass ratio in the range of approximately 10:1 to 11:1. Its high-pressure compressor achieves compression ratios up to 22:1—roughly twice that of earlier models. Turbine shrouds are constructed from ceramic matrix composites (CMCs), offering enhanced heat resistance with lower weight. Collectively, these advancements aim to lower fuel burn by about 16% compared to previous CFM engines.

An oil cooling system based on an eductor concept, adapted from the GEnx, is incorporated within the LEAP. Oil coolers are positioned along the fan duct lining and utilize a venturi effect to help sustain internal sump pressure. Furthermore, this engine includes some of the earliest FAA-approved 3D-printed components used in commercial jet propulsion.

The LEAP-1C variant, tailored for the Chinese-built Comac C919, reportedly excludes certain sophisticated technologies found in other LEAP models. This omission is believed to address concerns about intellectual property risks potentially aiding the rival ACAE CJ-1000A engine developed by China's state-owned Aero Engine Corporation. Experts observe that the LEAP-1C more closely resembles an enhanced version of the CFM56 rather than other LEAP variants.

Development

Originating from technologies cultivated under CFM's LEAP56 initiative launched in 2005, the engine was publicly introduced as LEAP-X on 13 July 2008 with the objective of succeeding the CFM56.

In 2009, the COMAC selected this engine for its C919 airliner, which was planned for testing beginning in 2016. Certification efforts involved 28 test engines managed by CFM, supplemented by an additional 32 units allocated among Airbus, Boeing, and COMAC for aircraft certification and test programs. The inaugural test engine produced thrust meeting specifications for the Airbus A321neo, later achieving increased thrust levels during evaluation.

The first flight test of the LEAP-1C took place on 6 October 2014 at Victorville, California, utilizing a Boeing 747 as a flying test platform. This variant features an updated thrust reverser design employing a single-piece O-ring instead of a two-piece door assembly, which reduces aerodynamic drag and enhances overall efficiency.

By April 2015, it was reported that the LEAP-1B had fallen short by as much as 5% relative to its targeted fuel consumption improvements.

On 19 June 2017, the engine was granted its 180-minute ETOPS certification by both the U.S. Federal Aviation Administration and the European Aviation Safety Agency.

Orders

On 20 July 2011, American Airlines revealed intentions to acquire 100 Boeing 737 aircraft equipped with LEAP-1B engines. Boeing officially approved this initiative on 30 August 2011, designating it as the Boeing 737 MAX. Southwest Airlines became the initial customer by placing a firm order for 150 units.

The approximate list prices stand at million for the LEAP-1A and million for the LEAP-1B variants.

CFM International provides "power by the hour" maintenance contracts, priced around per engine daily for the LEAP-1A, compared to per engine daily for the earlier CFM56 model.

In 2016, CFM secured 1,801 engine orders, with the LEAP engine backlog surpassing 12,200 units valued at over at list prices.

By July 2018, LEAP had accumulated an eight-year order backlog totaling 16,300 engines. Within five years of production, LEAP engines outnumbered the total CFM56 units produced over 25 years. It ranks as the second-most ordered commercial jet engine behind the CFM56, which achieved 35,500 orders over 44 years. On the A320neo platform, where it competes directly with the Pratt & Whitney PW1000G, LEAP held a 59% share of the market in July 2018, closely mirroring the CFM56’s previous 60% share on the A320ceo.

In 2020, GE Aviation disclosed a loss of 1,900 LEAP orders valued at , reducing the backlog to . Over half of these cancellations were linked to Boeing 737 MAX groundings; the remainder resulted from disruptions caused by the impact of the COVID-19 pandemic on aviation.

In May 2025, export restrictions were imposed by the U.S. Department of Commerce on LEAP engines destined for COMAC.

Production

The LEAP engine made its commercial debut in 2016 on the Airbus A320neo with Pegasus Airlines, with CFM delivering a total of 77 engines that year. Following the introduction of the 737 MAX, CFM supplied 257 LEAP engines during the first three quarters of 2017—110 in Q3 alone (49 to Airbus and 61 to Boeing)—aiming for a yearly total of 450. Production goals were set at 1,200 units in 2018, rising to 1,900 in 2019 and reaching 2,100 in 2020; this compares to a total of 1,700 CFM56 engines manufactured in 2016.

To satisfy increasing demand, CFM duplicated supply chains for approximately 80% of components and split assembly operations between GE and Safran facilities. GE expanded its assembly capacity by adding a plant in Lafayette, Indiana, complementing its existing site in Durham, North Carolina. More than three-quarters of parts are sourced from suppliers who undergo stringent “run-rate stress tests.” Meanwhile, competitors such as Pratt & Whitney encountered production delays on their PW1100G geared turbofan due to critical shortages of fan blades affecting deliveries for both the A320neo and Bombardier CSeries. Safran conducts assembly at Villaroche, France, with GE and Safran each responsible for half of annual output. Supplier Mecachrome planned to boost turbine blade manufacturing from 50,000 units in 2017 to roughly 125,000 in 2018.

By mid-2018, delivery schedules were running four to five weeks late but showed improvement as quality issues in casting and forging stabilized. The presence of multiple suppliers for key components helped avoid manufacturing bottlenecks. From a production volume of 460 units in 2017, output was projected to reach approximately 1,100 LEAP engines alongside about 1,050 CFM56s in 2018—surpassing the previous combined record of roughly 1,900 engines produced in a single year (2017). By 2020, annual production was expected to exceed 2,000 engines as CFM56 manufacturing declined. In total, deliveries reached 1,118 engines during 2018.

In the first half of 2019, CFM reported a revenue increase of 23% to , driven by deliveries totaling 1,119 engines; declining sales of CFM56s (258) were offset by growth in LEAP deliveries (861). Recurring operating income rose by 34% to , although early production expenses for LEAP caused an operating loss before anticipated improvements later that year. Revenue was forecasted to grow by about 15% for all of 2019; however, free cash flow depended heavily on resolving issues related to grounded 737 MAX aircraft.

LEAP production hit a total of 1,736 units in 2019 with orders and commitments amounting to 1,968 despite ongoing MAX groundings—backlog levels remained steady above 15,600 since 2018. Plans called for producing around 1,400 LEAP engines in 2020 including an average weekly output of ten LEAP-1Bs specifically for the Boeing 737 MAX. By March 2022, CFM targeted increasing annual output to approximately 2,000 engines by the following year from a delivery count of just over 845 units in 2021. In 2023 alone, more than 2,500 new orders increased backlog figures to around 10,675; deliveries rose sharply by roughly 38% to reach approximately 1,570 engines with expectations for an additional increase between twenty and twenty-five percent in 2024.

The challenging introduction of Pratt & Whitney’s PW1100G on the A320neo shifted customer preference toward LEAP engines. Market share for LEAP expanded from about 55% to nearly 60% during 2016; by early August of the following year (2017), new orders for LEAP outnumbered those for PW1100G almost tenfold. By mid-2024, nearly three-quarters of A320neo operators chose LEAP powerplants. Reliability concerns proved more significant with PW1100G-equipped aircraft compared to those powered by LEAP.

In February 2025, Safran Aircraft Engines entered into an agreement with India's Titan Engineering and Automation Limited to manufacture low-pressure turbine components for LEAP starting in early 2026. Additionally, a contract was signed with Hindustan Aeronautics Limited covering production of forged turbine parts.

Operations

The Boeing 737 MAX LEAP-1B entered commercial service in May 2017 with Malindo Air, initially flying around eight hours daily, whereas by July, the A320neo equipped with the LEAP-1A was achieving over ten hours of daily operation. Safran discovered a manufacturing defect in the LEAP-1B’s low-pressure turbine disks impacting approximately 30 engines, which led CFM to take measures to limit interruptions to both flight testing and engine deliveries.

In October 2017, a change in exhaust gas temperature indicated deterioration of the ceramic matrix composite (CMC) shroud coating within the high-pressure turbine, resulting in a leaking gap due to flaking. This problem affected eight engines currently in service, all of which required replacement of the coating. Safran allocated €50 million (equivalent to US$58 million) to resolve this matter, which involved more than 500 engines and caused shipment delays of about four weeks. The introduction of a permanent fix involving an enhanced CMC environmental-barrier coating began with deliveries starting in June 2018.

On 26 March 2019, during the period when Boeing 737 MAX aircraft were grounded, Southwest Airlines flight 8701 encountered engine difficulties on a ferry flight that necessitated an emergency landing. Following this incident, Southwest conducted inspections on 12 LEAP engines, while two additional airlines also performed their own engine checks. CFM advised increasing the frequency of fuel nozzle replacements to mitigate concerns related to carbon buildup (coking).

Applications

CFM International LEAP variants
Model	Application	Thrust range	Introduction
-1A	Airbus A320neo family	24,500–35,000 lbf (109–156 kN)	2 August 2016
-1B	Boeing 737 MAX	23,000–29,000 lbf (100–130 kN)	22 May 2017
-1C	Comac C919	27,980–30,000 lbf (124.5–133.4 kN)	28 May 2023

Specifications

Model	LEAP-1A	LEAP-1B	LEAP-1C
Configuration	Twin-spool, high bypass turbofan
Compressor	Single fan, 10-stage high-pressure, 3-stage low-pressure
Combustor	TAPS II (Twin-Annular, Pre-mixing Swirler second-generation)
Turbine	2-stage high-pressure, 7-stage low-pressure	2-stage high-pressure, 5-stage low-pressure	2-stage high-pressure, 7-stage low-pressure
Overall pressure ratio	40:1 (up to 50:1 at top of climb)
TSFC at cruise	0.51 lb/lbf/h (0.014 kg/N/ks)	0.53 lb/lbf/h (0.015 kg/N/ks)	0.51 lb/lbf/h (0.014 kg/N/ks)
Fan diameter	78 inches (2,000 mm)	69.4 inches (1,760 mm)	77 inches (2,000 mm)
Bypass ratio	11:1	9:1	11:1
Length	3.328 metres (10.92 ft)	3.147 metres (10.32 ft)	4.505 metres (14.78 ft)
Maximum width	2.543 metres (8 ft 4.1 in)	2.421 metres (7 ft 11.3 in)	2.659 metres (8 ft 8.7 in)
Maximum height	2.362 metres (7 ft 9.0 in)	2.256 metres (7 ft 4.8 in)	2.714 metres (8 ft 10.9 in)
Maximum weight	3,153 kilograms (6,951 lb) (Wet)	2,780 kilograms (6,130 lb) (Dry)	3,935 kilograms (8,675 lb) (Wet)

Variant	Take-off	Max. continuous	Application

External links