GE Aerospace expects it will soon complete a second round of GE9X dust-ingestion tests, insisting the efforts will help ensure the massive powerplant does not suffer the dust-related durability issues that have affected earlier engine models.
The tests come as GE prepares for the 105,000lb (467kN)-thrust GE9X to enter service on Boeing’s long-delayed 777-9, which Boeing aims to have in customers’ hands next year.
GE said on 28 May it is close to completing the second round of GE9X dust-ingestion tests, which build on an initial round of evaluations it completed in 2022.
The GE9X is the first powerplant GE has put through dust-ingestion tests prior to the engine entering service, reflecting an increased focus by the company on durability, GE says. The moves follow a spat of reliability issues that have affected GE’s and competitors’ engines in recent years.
The first round of GE9X dust tests involved 1,600 engine-run cycles and revealed no adverse findings, GE says.
“The 9X is one of our most-ready engines before it ever [gets] into service,” says GE future of flight engineering head Arjan Hegeman.
“This whole understanding and appreciation of engine durability, and the impact on overall product value to our customers, is now ingrained in this whole cycle of… development.”
Time will tell if the GE9X will be free of the durability shortfalls that afflicted other engines. Issues have particularly affected powerplants operated in dusty and sandy regions such as the Middle East.
GE, which co-owns CFM International with Safran Aircraft Engines, recently rolled out a durability improvement kit for CFM Leap-1A turbofans, which are one of two power options for Airbus A320neo-family jets. The kit consists of tweaked high-pressure turbine blades and nozzles.
In 2023, Safran chief executive Olivier Andries noted that Leaps were “suffering a lot in harsh conditions, especially the Gulf and India”.
GE is developing a similar kit for Leap-1Bs, which power Boeing’s 737 Max.
Additionally, the engine maker has made design changes to address dust- and sand-induced durability issues affecting its GEnx, one of two 787 power options, and its GE90, which powers first-generation 777s. The changes have involved components including shrouds, nozzles, blades and combustor linings.
“When we fly our engines over… certain regions of world, we ingest dust, and that dust interacts with the temperature and pressures and material systems in our engines and can cause degraded performance over time,” GE senior executive director of research Joe Vinciquerra said in late May.
GE did not initially understand the “material constituents [that compose dust], and how those constituents interacted with our exotic materials systems”, he adds.
It has since learned how to “recreate that dust”, says Vinciquerra.
“We can then go run experiments and tests – simulate what the engines are seeing in the real-world environment – which is what allows [us] to… actually go solve the engineering problem”.
GE’s competitors have suffered similar durability shortfalls, with all the companies saying they are putting more resources into addressing the issues.
Pratt & Whitney, for instance, has been working through widespread issues with its PW1000G family of geared turbofans.
Meanwhile, Rolls-Royce has been developing durability improvements for variants of its Trent engine family. Those include a durability package for Trent 1000s – the 787’s other power option – that is intended to extend the life of high-pressure turbine (HPT) blades and double how long the engine can remain in service between maintenance removals.
R-R is also working on durability improvements for Trent 7000s, which power A330neos, and Trent XWB-97s, which power A350-1000s. The XWB-97’s changes are to include redesigned HPT blades, nozzle guide vanes, ceramic matrix composite seal segments and combustor optimisation.
GE says it has run its GE9X through 27,000 simulated flight cycles and 17,000h of operation.
The company last year started shipping production-conforming GE9Xs to Boeing and plans to ramp production in the second half of this year.
