General Electric has started a second series of preliminary tests on a critical component of the 100,000lb-thrust GE9X turbofan engine selected to power the Boeing 777X aircraft family.

Testing began in mid-September on the high-pressure compressor rig at GE’s oil and gas turbine test facility in Massa, Italy, says GE9X programme leader Chuck Jackson.

GE officials have described the beginning of the core tests now as a significant step to reduce risk well before the 400-seat 777-9X is scheduled to enter service in 2020.

The rig testing come five years before GE expects to complete FAR Part 33 certification of the GE9X.

GE was scheduled to begin testing the high compressor rig two months earlier. The minor delay was caused by the need to prepare several new products, including the GE9X, ready for rig testing, Jackson says. Preparing the facility at Massa also took slightly longer than expected, he adds.

The overall development schedule for the GE9X remains on track, Jackson says.

The GE9X features a high-pressure section with a 27:1 compression ratio, or 20% higher than the GE90. It includes an additional stage of compression and a fourth-generation powered metal alloy that resists melting at higher temperatures.

In August, GE also began testing to validate the composite blades for the inlet fan for the GE9X.