The General Electric GE9X is the largest aircraft engine ever built. It is based on the GE90, which is currently found on the Boeing 777, and will be used to power the mighty Boeing 777X when it eventually enters commercial service.

In this article, we will take a closer look at the General Electric GE9X, its specifications, what makes it special, and how it generates the significant amount of thrust needed to get an aircraft as large as the Boeing 777X off the ground. We will also consider the GE9x in the wider context of the Boeing 777X project, and when the aircraft may enter commercial service.

The General Electric GE9X In A Nutshell

Credit: GE Aerospace

The General Electric GE9X is a high-bypass turbofan engine that has been developed by GE Aerospace for the Boeing 777X. The engine first ran on the ground in 2016 before being tested in the air for the first time a couple of years later. Flight testing took place on the wing of a Boeing 747-400, which was the only aircraft large enough to carry the GE9X (much like its predecessor, the GE90), and certification was then received in late 2019.

The first variant of the Boeing 777X to be produced, the 777-9, first took to the skies for a test flight in January 2020. It will become the US manufacturer’s flagship widebody aircraft when it eventually enters commercial service.

A Staggering 161-Inch Diameter

Credit: GE Aerospace

One of the standout features of the General Electric GE9X is its sheer size, as the engine’s diameter is a staggering 161 inches. To put that into perspective, it is larger than the fuselage of the Boeing 737. The fan alone, made up of 16 composite blades, is 134 inches in diameter.

The General Electric GE9X is made of advanced materials, such as ceramic-mix composites. This makes it relatively light for its size, weighing in at 21,230 lbs. The engine has a higher bypass ratio of 10:1, as well as an increased compression ratio of 60:1, which helps it to achieve 10% greater fuel efficiency than its predecessor, the GE90.

Generating More Thrust

Credit: Shutterstock

The General Electric GE9X is capable of generating up to 110,000 lbf of thrust, and its sheer size helps it to do this, with the majority of the thrust generated by air bypassing the turbines. Its large diameter allows more air to enter the engine, therefore extracting more power from the same amount of fuel when compared to smaller engines.

Higher combustion temperatures also play a role in extracting greater output from the fuel and help to improve fuel efficiency. With an increased focus on sustainability across the aviation industry, the General Electric GE9X’s fuel efficiency will help it stand out from the crowd and will contribute to wider net-zero goals.

All About The Boeing 777X

Credit: Boeing

The Boeing 777X will become the US manufacturer’s flagship widebody aircraft when it enters commercial service. It comes in two different passenger variants, the smaller 777-8 and the larger 777-9, with the latter proving vastly more popular with airlines around the world. The US manufacturer expects the 777X to act as a replacement for older 777s currently in service, and also to provide a fuel-efficient, high-capacity aircraft instead of the 747. It is also developing the cargo-carrying 777-8F.

Despite the hype, Boeing’s 777X project has been plagued by setbacks and delays, and Boeing now expects deliveries of the 777X to begin in 2027, some seven years behind schedule. As a result, several airlines have begun to air their frustrations, including Emirates, which is set to be the largest operator of the aircraft. Responding to the frustrations, Boeing’s Customer Leader for 777Xs and Freighters, Justin Hale, said at the 2025 Paris Air Show that:

“Emirates is not our first delivery airplane [inaugural customer], so when they talk about their airplanes coming in 2027, they’re not at the front of the delivery stream and that was their choice of positioning. I think it’s very important to be able to sit down with them and we do, regularly, with all of our customers,and talk about the progress we are making and the status of our certification work. We’re very involved. Every two weeks, we have direct phone calls with all of those customers as a group and then we meet individually with them continuously as well.”

Current Orders For The Boeing 777X

Credit: Shutterstock

Emirates currently has the largest number of Boeing 777Xs on order, with a staggering total of 270, made up of 35 777-8s and 235 777-9s. The airline is likely to use the aircraft to replace some of its older Boeing 777-300ERs, as well as expand the fleet. With its high passenger and cargo capacity, the 777X is well-suited to airlines operating a hub and spoke model, such as Emirates.

As mentioned, the Boeing 777-9 variant has proved significantly more popular than the smaller 777-8. The three largest operators, based on the current order books, are set to be Emirates, Qatar Airways, and Singapore Airlines. Other airlines with significant 777X orders include those detailed in the table below, per data from ch-aviation.

It remains to be seen how ongoing delays to the Boeing 777X project may affect any current and future aircraft orders. For now, at least, the impact has been minimal. After several years of controversy at Boeing, related to aircraft including the 737 MAX and 787, the US manufacturer will be keen to do all it can to ensure that the 777X lives up to the hype.

The World’s Current Largest Aircraft Engine

Credit: Wikimedia Commons

The largest aircraft engine currently in commercial service is the General Electric GE90, the engine on which the design of the GE9X is based. The GE90 is found on the Boeing 777, and first entered service on the 777-200 in 1995. Since then, around 3,000 GE90s have been built and delivered by the engine manufacturer, helping to cement its reputation as a mainstay in today’s aviation industry.

At the time of its launch, the General Electric GE90 was innovative in that it was made up of 22 carbon fiber composite fan blades, which provided double the strength of the previously used titanium fan blades. They were also one-third of the weight of their titanium counterparts. The first iteration of the General Electric GE90 had a compression ratio of 23:1, which at the time was industry-leading. Later generations of the GE90 offered even higher performance and greater fuel efficiency.

An Advanced Engine For An Advanced Aircraft

Credit: Photo: Boeing 

With its much-hyped operational performance, the Boeing 777X will be one of the most technologically advanced aircraft in the skies when it eventually enters commercial service. Its high capacity puts it comfortably between the Airbus A350 and A380, making it the ideal aircraft for a number of operators around the world, including Emirates and Qatar Airways.

The Boeing 777X will also feature unique folding wing tips, adding to its modern appearance, and each wing will be adorned by a General Electric GE9X engine. Being the largest commercial aircraft engine in service, the GE9X’s sheer size only adds to the 777X’s dominating appearance. Despite ongoing delays to the project, the Boeing 777X has proved commercially successful for the US manufacturer, with a large number of orders already on the books. All eyes are now on Boeing to see if it will be able to deliver the 777X in 2027.