GE's Boeing 747-100 testbed with GEnx engine (N747GE)

GE's Boeing 747-100 testbed with GEnx engine (N747GE)

A while back to celebrate the Boeing 787 Dreamliner’s test flights, I posted Ten Interesting Facts about the Rolls-Royce Trent 1000 Engines. Now that Boeing 787 ZA005 with GEnx engines are flying as well, I find it only fair to give 10 interesting facts about them:

#1 GE estimates the GEnx engines projected to be sold in the next 20 years will emit an about 77 million fewer tons of greenhouse gases than older comparable engines.

#2 The GEnx engine will remain on wing 30 percent longer and is 30% quieter than comparable engines in service today.

#3 The GEnx-1B for the Boeing 787 Dreamliner has a fan diameter of 111 inches and the GEnx-2B version for the Boeing 747-8 has a fan diameter of 105 inches.

#4 The GEnx engine has 18 fan blades, which is about half as many as GE’s CF6 engine.

#5 If an airline were to replace 20 of 200-to 300-passenger aircraft with next-generation jets powered by GEnx engines, it would save nearly $37 million in fuel costs annually, based on jet fuel costs of $2.50 per gallon.

#6 The GEnx engine has one of the highest pressure ratios ’“ 23:1 that sets the high pressure compressor apart from other engines.

#7 By using GEnx engines, that same fleet could save nearly 500 million gallons of jet fuel each year. Enough to fly more than 12 million people from New York City to London on Boeing 787 Dreamliner jets.

#8 The GEnx engine is the only choice on the Boeing 747-8 and is one of two choices on the Boeing 787.

#9 The engine has composite fan blades with titanium leading edges.

#10 The GEnx has a fan bypass ratio of 19:2, which also helps reduce noise.

Other cool stuff:
* Interactive page on the GEnx Engines
* Videos on the engine
* Video & pictures of Boeing 787 ZA005 with GEnx engines, first flight

Image: Rick Schlamp

EDITOR-IN-CHIEF & FOUNDER - SEATTLE, WA. David has written, consulted, and presented on multiple topics relating to airlines and travel since 2008. He has been quoted and written for a number of news organizations, including BBC, CNN, NBC News, Bloomberg, and others. He is passionate about sharing the complexities, the benefits, and the fun stuff of the airline business. Email me:
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#6 The GEnx engine has one of the highest pressure ratios — 23:1 that sets the high pressure compressor apart from other engines.

#10 The GEnx engine has one of the highest pressure ratios — 23:1 that sets the high pressure compressor apart from other engines.

I got it the first time 🙂

Heh…I thought it was double interesting.

Thanks, I have updated with a new interesting fact :).


Dunno if this is interesting or not, the fan blades are made at a subcontractor named C-Fan, just outside San Marcos, TX.

I drive by them everyday on the way to my office.



Great info, David. You can see one of the really cool fan blades in our gallery. So beautiful, almost looks like art.


John (comment 1):
#06 pressure ratio
#10 bypass ratio
not the same!

So why does the GEnx engine rotate the British way. Clockwise facing the front?

Hey Pete!

Really good question, let me see if I can find you an answer!


Alright! Heard fro Kent Moeller, GEnx Program Manager in Seattle and he says, “Unlike other GE engines the Fan and Booster on the GEnx rotates in the opposite direction to the Compressor. This was done to improve and manage the airflow more efficiently through the entire engine length.”

GE has some good info on the GEnx at There are movies there that demonstrate the counter-rotation

I think the pressure ratio and bypass ratio came from wikipedia. Unfortunately the BPR is wrong, should be about 9:1.
Also the GE-nx pressure ratio is more like 42. 23 is for the HPC only.

Things could have changed since I posted this, but I got all the facts direction from GE.


The above GE link has some interesting numbers for 4 different variants of the engine, including BPR and PR.

Best regards Pete

Question: How much does it cost to buy a GEnx2B engine? I presume it would be between $10-15 million but I would like to know GE’s RRP.

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