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The Single Aisle Leader

CFM International has a proven track record of delivering high-quality engines like the CFM56 and the LEAP-1. With the CFM RISE likely to follow, the company will probably retain its position as single-aisle market leader for the foreseeable future.

Issue: 03-2023By Joseph NoronhaPhoto(s): By Safran Group
The CFM56-7B features an advanced digital engine control system that optimises fuel consumption and reduces emissions

In February 2023, Air India made the dramatic announcement that it would buy 800 CFM LEAP-1A and LEAP-1B turbofan engines to power 210 Airbus A320/A321neo aircraft and 190 Boeing 737 MAX aircraft. This order emanating from the world’s third largest and fastest-growing aviation market is one of the biggest ever commercial jet engine deals. It is proof, if proof were needed, of the continuing confidence of the world’s airlines in CFM International.

CFM International, a 50-50 joint venture between two of the world’s leading aerospace companies – General Electric (GE) of the United States and Safran Aircraft Engines (SAE) of France – accounts for about 39 per cent of the global commercial engine market. This makes it the largest such manufacturer in the world. A remarkable feature of the enduring transatlantic partnership that turns fifty next year is that its stunning success is based not on a variety of engines but on just two engine families – the CFM56 and the LEAP-1. Both are meant primarily for the single-aisle airliner segment, which constitutes 80 per cent of the global commercial fleet. In fact, of India’s total inventory of around 700 airliners, only 45 are twin-aisle jets, and the rest are single-aisle aircraft. CFM therefore is in a sweet spot where demand for engines continues to remain strong.


CFM International was established on September 24, 1974. Since both GE and SAE (then known as Snecma) happened to be developing new engines, it seemed an excellent idea to pool their resources and expertise and develop an engine capable of taking on all competitors. The new high-bypass turbofan, initially known as the CFM56, combined GE’s high-pressure compressor and combustor technology with Snecma’s low-pressure turbine technology. The joint venture’s name also suggested itself: “CF” stands for GE’s designation for commercial turbofan engines, while “M56” was the name of Snecma’s original proposal.

However, CFM didn’t have it easy for several years. According to company lore, it was not until March 1979 that the first firm order came – just two weeks before the programme was due to be shelved. Thereafter there was no looking back. In quick succession the CFM56 was selected to power various military and civilian aircraft. Its main customers were the ubiquitous singleaisle aircraft like the Boeing 737 and the Airbus A320 families. Over 35,500 CFM56 engines in several different commercial and military variants have now been sold to more than 600 operators worldwide. If any engine exceeds this figure it will probably be the second CFM International product – the LEAP turbofan.

Over 35,500 CFM56 engines in several different commercial and military variants have now been sold to more than 600 operators worldwide

Since the LEAP (Leading Edge Aviation Propulsion) first entered service in 2016, it has experienced the fastest order ramp up in commercial aviation history. It has already secured over 17,500 orders and commitments against around 10,000 orders and commitments that its chief rival, the Pratt & Whitney PW1000G, has obtained. It is the second most-ordered jet engine ever, lagging only its predecessor, the CFM56.


The CFM56 was a revolutionary engine that brought unmatched levels of fuel efficiency and reduced noise at a time when rising fuel prices and green pressures were beginning to turn the heat on the aviation industry. Among the many reasons for the success of the CFM56 these stand out:

  • Efficiency: The engine is highly fuel efficient, which translates into lower operating costs. CFM International constantly strives to further increase fuel efficiency.
  • Innovation: CFM invests heavily in R&D to improve its offerings. The CFM56 engine has undergone several upgrades and improvements over the years to increase its performance and reduce emissions. The CFM56-5B and CFM56-7B feature a higher bypass ratio with advanced high-pressure compressors and combustors. Improved materials have helped reduce weight and increase durability. The CFM56-7B, which powers the Boeing 737 Next Generation family, features an advanced digital engine control system that optimises fuel consumption and reduces emissions. It carries 40 per cent more passengers almost 120 per cent farther using 23 per cent less fuel than the first CFM56 model.
  • Reliability: The engine has a high dispatch reliability rate and a low rate of in-flight shutdowns.
  • Durability: One of the key features of the CFM56 is that it can operate for long periods of time without major maintenance or repair. It has a modular design, so individual components can be easily replaced or upgraded as needed. This reduces maintenance costs and downtime.
  • Versatility: Although the CFM56 engine mainly powers single-aisle airliners like the Boeing 737 and Airbus A320 it also equips a wide range of other aircraft, including twin-aisle airliners like the Airbus A340. The CFM56-7B is the exclusive engine for the Boeing 737NG airliner. Over 15,000 CFM56-7B engines have been delivered to power Boeing 737NG aircraft, making it the most popular engine-aircraft combination in commercial aviation history. The CFM56-5B was the engine of choice for the A320ceo family, having been selected to power nearly 60 per cent of the A320 aircraft ordered.


In July 2008, GE and SAE decided to extend their partnership well before it was due to expire in order to demonstrate their enduring commitment to the joint venture. Accordingly they announced an agreement to extend CFM International through to the year 2040. They established a single CFM services company to support all future CFM engines. They also announced the launch of the new LEAP-X engine, which at the time had no aircraft candidate. However, fairly soon thereafter Airbus followed by Boeing announced upgraded versions of their single-aisle planes intended to be 15 to 20 per cent more fuel efficient than their earlier models. And LEAP got the platforms it was anticipating.


While the Airbus A320neo may be powered by either the CFM LEAP-1A or the Pratt & Whitney PW1100G turbofan, the Boeing 737 MAX is exclusively powered by the LEAP-1B. The first LEAP-1A-powered Airbus A320neo entered service with Pegasus Airlines in August 2016. The LEAP-1B-powered Boeing 737 MAX followed in May 2017, entering service with Malindo Air.

The main reasons for the LEAP turbofan’s success are below.

  • Improved Efficiency: Thanks to its higher bypass ratio and advanced blade design, LEAP is over 15 per cent more fuel efficient than its predecessor, the CFM56. The engine also has lower noise levels.
  • Advanced Technology: LEAP features 3D-printed parts made from lightweight materials like titanium and are designed to be more durable and heat-resistant than traditional cast metal parts. Carbon fibre composites (CFC) and ceramic matrix composites (CMC) also help to improve efficiency and durability while reducing weight.
  • Reduced Environmental Impact: LEAP’s use of a high-pressure turbine allows for greater power output. Its advanced combustion technology means lower emissions. Overall, LEAP has a higher thrust-to-weight ratio than previous engines, which translates both into better performance and efficiency.
  • CFM’s Record: The CFM56 engine brought CFM International a strong reputation for high-quality, reliable engines and excellent service. This made LEAP a popular choice among aircraft manufacturers and airlines. It has quickly become one of the best-selling turbofans in history.
  • Exclusive Customers: As of January 31, 2023, the Boeing 737 MAX had secured 5,314 orders and made 1,068 deliveries with the LEAP-1B as its exclusive engine. In the same period, the A320neo family had secured 8,689 orders and made 2,608 deliveries with the LEAP-1A as the preferred option. The Chinese COMAC C919 exclusively powered by the LEAP-1C is expected to enter into regular service in spring 2023 and may emerge as a third major LEAP customer.


CFM is once again where it was in 2008 when it felt the need to look ahead. Although LEAP is doing extremely well it will eventually run out of steam as all engines must. Therefore on June 14, 2021, the CFM International RISE Program was launched with the aim of reducing fuel consumption and carbon emissions by more than 20 per cent compared to today’s most efficient engines, as well as ensuring compatibility with alternative energy sources. The RISE program is covered in detail elsewhere in this issue. Like the CFM56 and the LEAP engines, RISE will be initially for the single-aisle market. So the big question is what will Airbus and Boeing do?

In November 2022 Boeing CEO David Calhoun surprised industry observers by announcing that the company was not considering development of an all-new airliner until the 2030s. Since Airbus has already taken a substantial lead over Boeing in the single-aisle market, it too is unlikely to start on a new airliner anytime soon. Hopefully they will change their minds because shared intent and close cooperation between airframe and engine manufacturers is the best recipe for the progress of aviation.

CFM International’s phenomenal success over the past half century is attributable to its steely-eyed focus on commercial engines meant for the single-aisle airliner segment. It has a proven track record of delivering high-quality engines like the CFM56 and the LEAP-1. With the CFM RISE likely to follow, the company will probably retain its position as single-aisle market leader for the foreseeable future.