In early 2018, of 1277 orders for the B787, 681 selected the GEnx (%), 420 the Rolls-Royce Trent 1000 (%) and 176 were undecided (%). The 2,000th GEnx was delivered by November 2019, 15 years after the engine launch, as it logged 4.5 million flight cycles and 26 million hours among 60 operators. Design The GEnx is derived from the GE90 with a fan diameter of for the 787 and for the 747-8. To reduce weight, it features 18 composite fan blades, a composite fan case and titanium aluminide stage 6 and 7 low-pressure turbine blades. Fuel efficiency is improved by 15% compared to the CF6, the bypass ratio reaches up to 9.0:1 and the overall pressure ratio up to 58.1:1. It has a 10 stage high-pressure compressor and is quieter, helped by larger, more efficient fan blades. It stays on wing 20% longer, uses 30% fewer parts to lower maintenance costs and has a contra-rotating architecture. The Lean combustor reduces NOx gases with required pressure loss and backflow margin. Fan blades have steel alloy leading edges and the composite fan case reduces thermal expansion. To reduce fuel burn, the 23:1 pressure ratio high-pressure compressor is based on the GE90-94B, shrouded guide vanes reduce secondary flows and counter-rotating spools for the reaction turbines reduce load on guide vanes. To reduce maintenance cost and increase engine life, spools with lower parts count are achieved by using blisks in some stages, low blade counts in other stages and by using fewer stages; internal engine temperatures are reduced due to more efficient cooling techniques and debris extraction within the low-pressure compressor protects the high-pressure compressor. Applications Boeing 747-8 Boeing 787 Dreamliner Variants Specifications See also References External links High-bypass turbofan engines GEnx 2000s turbofan engines