GE Aviation this week reported that testing on the high pressure compressor (HPC) module for the GE9X engine that will power Boeing’s 777X aircraft continues to yield “very promising results,” achieving a 27:1 pressure ratio–the highest of any commercial aircraft engine. The tests began in September at the GE Oil & Gas testing facility in Massa, Italy, and the module has accumulated close to 300 hours of testing today.

“The testing has validated the efficiency and operability of the HPC module design well ahead of the entry into service and supports our plan to deliver a 10 percent fuel burn improvement over today’s GE90 engines,” said Bill Millhaem, general manager of the GE90/GE9X program at GE Aviation.

A 90-percent scale of the full-size HPC, the module carries more than 1,000 pieces of instrumentation and a GE LM2500 engine generates more than 29,000 horsepower to drive it during the test. Schedules call for the module to have accumulated 450 run hours by the time GE finishes the test rig in March. GE plans to begin testing a second HPC module at the Massa, Italy test facility later this year and a third HPC module prior to first engine to test in 2016.

GE plans to spend $300 million in 2014 on maturation testing of technologies for the new GE9X engine. Testing includes the Universal Propulsion Simulator (UPS) fan performance tests now underway at Boeing’s Seattle, Washington facility. Engineers expect the test to provide key data on the GE9X fan, which features the largest fan diameter of any commercial aircraft engine to date.

The GE9X engine falls into the 100,000-pound-thrust class. Key features include a 133-inch diameter composite fan case and 16 composite fan blades; an 11-stage high pressure compressor; a 3rd-generation TAPS (twin annular pre-swirl) combustor; and ceramic matrix composite (CMC) material in the combustor and turbine.

GE has scheduled the first full core test for 2015, the first engine test in 2016 and the start of flight testing on GE’s flying testbed in 2017. It expects to gain engine certification in 2018.