CFM International

Take any photo of the apron at a European airport and count the engines: chances are high that the majority of them carry the lettering CFM. Every Boeing 737 since the -300, a large part of the A320 family and by now also China’s C919 fly with powerplants from CFM International. Behind the name is not a classic manufacturer but a joint venture: the American GE Aerospace and the French Safran have split the company exactly half and half since 1974. If you spot narrowbody jets, you almost always have CFM in the frame – and you can read quite a lot about the aircraft from the engines.

How two partners became a world market leader

In the early 1970s, the French company Snecma wanted to build an engine in the ten-ton thrust class for new short- and medium-haul jets. Until then, it had mainly built military engines, so it lacked experience in the civil business – and with it a partner who could bring it. Pratt & Whitney preferred to continue developing its own JT8D at the time, and Rolls-Royce was struggling with financial problems. That is how General Electric came into play, bringing a suitable core engine with its military F101 engine.

It didn’t go entirely without politics. Only after an agreement between Presidents Richard Nixon and Georges Pompidou at their meeting in Reykjavík in 1973 was the way clear. On January 24, 1974, GE and Snecma signed the agreement, and in September CFM International was founded. The name is a mix of both worlds: “CF” from the civil GE series, known from the CF6, and “M56” from the project designation at Snecma.

The division of labor has been clearly regulated to this day. GE supplies the high-pressure section, meaning the core engine with compressor, combustor and high-pressure turbine. Safran – as the former Snecma is called today – is responsible for the fan, the low-pressure compressor and the low-pressure turbine. Both partners split development and production evenly, and each handles final assembly, sales and service with its own capacity. CFM is headquartered in the Cincinnati area in the US state of Ohio, near the headquarters of GE Aerospace in Evendale. In 2021, both sides extended the partnership to 2050, explicitly including the service business.

The slow start of the CFM56

The demonstrator first ran on June 20, 1974, in Evendale. Technically, the CFM56 was ready quickly, but commercially it was not for a long time. For years, no new aircraft turned up that needed exactly this engine. The rescue came by a detour: the re-engining of older four-engine aircraft.

In March 1979, United Airlines decided to retrofit its DC-8s with CFM56s. On November 8, 1979, the engine received certification simultaneously from the US aviation authority FAA and the French DGAC. In April 1982, Delta Air Lines flew the first converted DC-8 Super Seventy in scheduled service. The probably most important order came from the military: in early 1980, the US Air Force chose the CFM56 for its tanker fleet. As the F108, it turned the old KC-135 into the quieter and more economical KC-135R. Later followed the US Navy’s E-6 and E-3 AWACS aircraft, including for Saudi Arabia.

The breakthrough in civil new-build came with the Boeing 737. Boeing wanted to modernize its bestseller, and the old Pratt & Whitney JT8D was loud and thirsty. From 1984, the 737-300 flew with the CFM56-3 – and ever since, every new 737 has had a CFM engine under the wing.

The CFM56 family at a glance

The CFM56 is actually a whole family of engines that was adapted to different aircraft over the decades. For spotters, these versions are the most interesting:

CFM56-3: the flat shape of the Classic

The CFM56-3 is the engine with the most distinctive look. The 737 sits very low, and the CFM56’s fan was much larger than that of the slim JT8D. So that the engine wouldn’t scrape the ground, CFM moved the accessories from the bottom to the side and flattened the nacelle and inlet on the bottom. The fan diameter is about 152 centimeters. This oval shape is still the surest feature of the 737-400, 737-500 and their sister the -300 – including on the freighters converted from these aircraft.

CFM56-5: the first Airbus partner

In February 1987, the first Airbus A320 took off on its first flight – with CFM56-5s. On the A320 family, though, CFM was never alone: airlines could choose between the CFM56-5 and the IAE V2500. The more powerful CFM56-5C, by contrast, was built exclusively for the four-engine A340-300 and the shorter A340-200, which entered service in 1993. Probably the most famous CFM56-5B hung under an A320 of US Airways: on Flight 1549, both engines ingested birds and lost almost all their thrust – the aircraft then landed on the Hudson.

CFM56-7B: the backbone of the 737 NG

For the 737 Next Generation, CFM developed the CFM56-7B, which ran for the first time in April 1995. It powers all versions from the 737-600 through the 737-700 and the 737-800 to the 737-900ER, plus the Boeing Business Jet and the maritime patrol aircraft P-8 Poseidon. In 2010, the CFM56-7BE, an improved version that used about 1.6 percent less fuel in tests, was certified. Because the 737-800 is so widespread in Europe, the CFM56-7B is probably the engine you have photographed most often.

Production for new airliners ran out with the last 737 NGs and A320ceos around 2019/2020; after that, CFM built only small numbers, for example for military 737s and as spare engines. By July 2016, more than 30,000 CFM56s had already been built – which makes it the most-produced engine in civil aviation.

LEAP: the new generation

In July 2008, CFM announced the successor under the name LEAP-X. The goal was a significantly more economical engine for the next generation of narrowbody jets. The first complete LEAP ran in September 2013. Compared with the CFM56, CFM promises about 15 percent lower fuel consumption and correspondingly less CO₂.

Technically, the LEAP contains much that was previously reserved for large engines. The fan has only 18 blades – half as many as the CFM56-5B. They are made of carbon fiber that is woven into shape in three dimensions on a loom, soaked with resin and cured; a titanium leading edge protects them. In the turbine, CFM relies on ceramic composites that withstand higher temperatures than metal. And the combustor’s fuel nozzles come from a 3D printer – the LEAP was among the first civil engines with such FAA-approved parts.

LEAP-1A on the A320neo

On the A320neo, A321neo and A319neo, the LEAP-1A competes with the geared turbofan PW1100G from Pratt & Whitney. Pegasus Airlines flew the first scheduled service in August 2016. For identification, note: both neo engines are significantly thicker than the CFM56 or V2500 of the ceo, but hard to tell apart from each other. The manufacturer’s name is often on the nacelle; looking up the registration is reliable.

LEAP-1B on the 737 MAX

For the Boeing 737 MAX, CFM again had to live with the 737’s limited ground clearance. The LEAP-1B therefore has a smaller fan than the Airbus version, at about 176 centimeters. Boeing also mounted the engines further forward and higher on the wing. Typical are the serrated trailing edges on the cowling, the so-called chevrons. Malindo Air, today Batik Air Malaysia, took over the first operation in May 2017. In Europe, you see the LEAP-1B most often on the 737-8-200s of Ryanair – the entire Ryanair fleet of 737 NGs and MAXs flies with CFM.

LEAP-1C on the COMAC C919

The C919 from COMAC flies exclusively with the LEAP-1C. The LEAP-1C was the first LEAP version in flight testing – on a converted Boeing 747 from GE. At the end of May 2023, the C919 entered scheduled service with China Eastern Airlines. In Europe, it has hardly been seen so far (as of October 2026).

How to recognize CFM engines while spotting

The most important sentence for practice: On every Boeing 737 from the -300 on, CFM is a given. So you only have to determine the generation, and then you also know the engine version. It gets interesting at Airbus, where CFM always had a competitor.

On the A320ceo, the shape is a good clue: on the CFM56-5, the cowling ends earlier, and behind it you see the narrower core with the exhaust cone. The V2500, by contrast, is long and continuously cowled. You will find more about the family itself in the article Telling the A318, A319, A320 and A321 apart. On the neo, it is trickier because the LEAP-1A and PW1100G are both large and round. There the lettering helps if the airline leaves it on, and otherwise the route via the registration: fleet lists and flight-tracking services usually name the engine variant. Within one airline, the choice is generally uniform, but leased aircraft can differ.

General tips for identifying powerplants – from the exhaust cone to the fan shape – are collected in the article Identifying engines. The ceo-neo question is explained in detail in A320neo or ceo?.

Where to see CFM engines in Europe

Practically everywhere – which is why it is worth looking at the places where you get many variants at once. Ryanair is at home in Dublin; from the Mound at Dublin Airport, you often see 737-800s with CFM56-7B and 737-8-200s with LEAP-1B directly one after the other. That is the perfect exercise for telling NG and MAX apart by the engines. At Palma de Mallorca Airport, too, 737s of all generations land in summer, for example from TUIfly, among countless A320ceos and neos.

At the big German hubs, you get the Airbus side. At Frankfurt Airport, the A320 families of Lufthansa and many visiting airlines mix; from the Zeppelinheim viewing platform, it is worth looking at the nacelles. At Munich Airport, this works well from the visitors’ hill (Besucherhügel). easyJet flies both older A319s and A320s and neos – ideal for comparing ceo and neo in the same livery.

Brand-new neos, many of them with LEAP-1A, you see where Airbus assembles them: in Hamburg-Finkenwerder, where aircraft of the A320 family roll off the line – tips in the article Spotting at Airbus Finkenwerder – and at Toulouse-Blagnac Airport. There, the Aeroscopia museum also shows older Airbus types up close.

CFM in competition

On narrowbody jets, CFM today shares the market mainly with Pratt & Whitney. On the A320neo, the LEAP-1A and the geared turbofan PW1100G face each other directly; the German engine specialist MTU Aero Engines is also involved in the geared turbofan. On the 737, by contrast, there has been no alternative for decades. That makes CFM the most important supplier for Airbus and Boeing alike in the class in which most aircraft are built.

On today’s widebodies, CFM plays no role – the four-engine A340-200/-300 was the exception. There, the parent GE Aerospace and Rolls-Royce compete with their own engines. The joint venture of GE and Safran therefore concentrates on the narrowbody class.

The look ahead is called RISE. The program unveiled in 2021 is investigating an open fan without a shroud that could need about 20 percent less fuel than a LEAP. Service on scheduled flights is targeted for the mid-2030s (as of October 2026). For spotters, that would be a real break: engines with visible rotor blades under the wing of an airliner have so far only been known from turboprops.

Museums and background

Early CFM56 applications are found today mainly in museums and military fleets. The DC-8 Super Seventy has practically disappeared from scheduled service, while the KC-135R keeps flying with the US Air Force and regularly turns up at military airfields and airshows. Large collections like the National Museum of the US Air Force in Dayton, not far from the CFM headquarters near Cincinnati, or the Museum of Flight in Seattle show Boeing and military history around these powerplants. In France, the Musée de l’Air et de l’Espace is in Le Bourget, where the Paris Air Show also takes place every two years – a must-attend date for anyone who wants to see new engines up close.

And because you don’t just see engines: a departing A320ceo with CFM56 sounds audibly different from a 737 MAX with LEAP-1B. How to capture such differences is shown in the article Recording engine sound.

Conclusion

CFM International is the engine manufacturer you photograph most often without consciously thinking about it. From a politically delicate joint venture of GE and Snecma, the CFM56 became the most-produced engine in civil aviation – first on converted DC-8s and KC-135s, then on every 737 since the -300 and a large part of the A320 family. With the LEAP, CFM has carried this position into the neo and MAX generation and is now also aboard the Chinese C919.

For your sightings, CFM is a practical key: on the 737, the nacelle tells you the generation; on Airbus, the engine separates ceo and neo. Only where a second option exists does the registration remain the surest way.