The only engine ever offered on a 747-8

The GEnx-2B is the only engine ever offered on the 747-8, selected by Boeing as the sole propulsion supplier in January 2006 - a reversal of the three-engine competition that decided classic 747 purchases.

Key facts
Applications	Boeing 747-8F and 747-8 Intercontinental; later selected for the VC-25B
Thrust	66,500 lbf (296 kN) takeoff rating - one rating for the 747-8
Bypass / fan	8.0:1 at takeoff (7.4:1 top of climb); 104.7 in fan - the largest fan on any 747
Launch customers	Cargolux (747-8F, first revenue flight 12 October 2011); Lufthansa (747-8I, service 1 June 2012)

The GEnx-2B first flew on the first 747-8F in February 2010 - the first GEnx variant to fly - and was FAA/EASA certified in August 2011. Cargolux launched the freighter on 12 October 2011 and Lufthansa launched the 747-8 Intercontinental on 1 June 2012.

Despite being the only choice, the engine offered a major step forward: composite fan blades and case, a TAPS (Twin Annular Premixing Swirler) combustor cutting NOx by roughly 60 percent versus the CF6, and about 13 percent better fuel burn than the CF6-80C2 on the 747-400.

GEnx-2B production continued to the very end of the 747 line: the last 747-8F, delivered to Atlas Air in January 2023, closed out 54 years of 747 manufacturing.

The engine that kept the 747 alive

The GEnx-2B is the reason the 747-8 exists. Boeing needed an engine roughly 10 percent more efficient than the CF6-80C2 to make the -8's range and payload targets, and GE's GEnx - sharing its core and about 80 percent of its line-replaceable units with the 787's GEnx-1B - delivered it. The composite fan and case and the TAPS combustor cut fuel burn around 13 percent against the CF6 and NOx roughly 60 percent, which is what allowed the stretched -8 to fly longer routes than the -400 it replaced.

It remains the only engine ever offered on a 747-8. The single-source decision, taken in 2006, was a reversal of the three-engine competition that had defined 747 purchases since the -400, and it meant the 747-8's entire production run, including the last 747 freighter delivered to Atlas Air in 2023, ran on this one powerplant.

Technology lineage

Because the GEnx-2B shares so much with the GEnx-1B, the 747-8's engine is a case study in how aero-engine programmes scale: the commercial core that GE designed for the 787's smaller diameter was adapted, at scale, to become the sole engine of the largest passenger 747 variant. The 104.7-inch fan is the largest ever fitted to a 747, a physical statement of the same efficiency story.

Related

• Fuel system
• Hydraulic systems
• Electrical system
• 747-8 systems differences