Aircraft

World's largest jet engine earns official US certification

World's largest jet engine ear...
The world's largest commercial jet engine, the GE9X, fitted to a test aircraft
The world's largest commercial jet engine, the GE9X, fitted to a test aircraft
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The world's largest commercial jet engine, the GE9X, fitted to a test aircraft
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The world's largest commercial jet engine, the GE9X, fitted to a test aircraft
The GE9X in the test rig at GE Aviation testing facility
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The GE9X in the test rig at GE Aviation testing facility
The GE9X on the wing of the 747 test bed
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The GE9X on the wing of the 747 test bed
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It’s been a long road of research, development and, more recently, testing but the team at GE Aviation has now earned official US certification for the world’s largest commercial aircraft engine. The Federal Aviation Administration’s (FAA) approval of the GE9X follows thousands of hours of testing, and clears the engine for life aboard the world’s largest twin-engine aircraft, the Boeing 777X.

GE Aviation fired up its GE9X for the first time back in 2016, showing off a monstrous engine with a front fan measuring more than 3 m (9.8 ft) across and an ability to generate 100,000 lb of thrust. The company made a few design tweaks ahead of a maiden flight in 2018, reducing the number of fan blades from 22 to 16 to help make it lighter, while increasing the size to measure 3.41 m (11.2 ft) across.

Before that maiden flight even took place, GE Aviation said it had hundreds of orders on the books from a range of customers in the aviation space, but its primary focus has been the forthcoming family of wide-body planes from Boeing. Developed to power these next-generation 777X passenger jets, we saw the GE9X fitted to the aircraft for the first time last year, ahead of a maiden flight in January of 2020.

Meanwhile, the FAA has been busy putting the enormous engine through its paces. The certification process involved eight engines being put through just under 5,000 hours and 8,000 cycles of testing, resulting in a Part 33 certification from the aviation regulators. GE Aviation says it is now carrying out a further 3,000 hours of ground-testing to earn what’s known as Extended Operations approval, which is required for flights that travel a little farther from airports.

The GE9X in the test rig at GE Aviation testing facility
The GE9X in the test rig at GE Aviation testing facility

“It takes the world’s best talent in jet propulsion to create a game-changing product like the GE9X engine,” says John Slattery, president and CEO of GE Aviation. “There is no substitute that can achieve the combination of size, power and fuel efficiency of the GE9X. This engine will deliver unsurpassed value and reliability to our airline customers. I want to congratulate the entire GE9X team and thank Boeing, our partners and suppliers for the collaboration on this incredible achievement.”

The GE9X engine itself is as wide as a Boeing 737 fuselage, and is 10 percent more efficient than the GE90 engine used to power Boeing’s current generation of 777s. It is also claimed to offer five percent better fuel consumption efficiency than any other engine in its class, and also produce less smog-causing emissions.

“Just as the GE90 pioneered new technology for commercial aircraft engines more than 25 years ago on the Boeing 777, the GE9X sets the new standard for engine performance and efficiency thanks to the incorporation of GE’s most advanced technologies developed over the last decade,” says Bill Fitzgerald, vice president and general manager of Commercial Engines Operation for GE Aviation.

Source: GE Aviation

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6 comments
guzmanchinky
So cool. Whatever happened to that engine by Rolls Royce that had a gearbox between the jet and the fan?
Kpar
I am surprised the article did not mention that the GE9X is a new type of "super-high-bypass" turbofan called a GTF- Geared Turbo Fan, in which the compressor stage is powered from a much smaller turbine section through a planetary gear to lower the fan speed. You cannot make the fan disk turn faster at such large diameters without the tips exceeding Mach 1. This means the turbine (hot side) must be much more robust to put out the required power. This will (eventually) filter down to smaller engines as the new turbine cores become more efficient.
Username
5% efficiency gain after 4 years of practical development? Doesn't seem like much.
Cryptonoetic
Per, Kpar, with a fan diameter of 134 inches, max RPM would have to be ~1900 RPM to keep blade tips from exceeding the speed of sound.
ljaques
@Username, 5% is a massive improvement in an already extremely previously-engineered mechanical system. I wonder how many millions of gallons of fuel (for each airline) it will save over a similar 4 year period.
windykites
Just imagine fuelling this engine with liquid hydrogen. Super low emissions. Hydrogen has less energy per litre than jet fuel, but the extra power of the engine would make up for this.
Amazing to reduce the number of fan blades from 22 to 16. What a cost saving!