As Boeing pilots steered the 777-9 down the Farnborough, England, runway past airshow spectators, Harry Chieu watched confidently from the flight line as the airplane’s GE9X engines powered the demonstration flights. Chieu and his colleagues know the world’s largest, most powerful engines as well as the engineers who designed them. Since the first GE9X engines arrived in 2019 at the Everett, Washington, factory, ready to be installed, Chieu is one of the GE team members who’ve maintained the engines.

“We’re the first ones to really see the engine,” said Chieu, who is part of GE’s Customer & Product Support field services team. “The goal is to have the engine 100 percent ready to support flight test or ground test activity.”

Chieu has worked for GE more than 40 years. Even with decades of experience, maintaining the GE9X engine to prepare it for entry into service with airlines around the world brings new challenges compared to servicing an engine already operating for decades, like the CF6. Not only are Chieu and the rest of the field service crew performing recommended maintenance based on GE’s knowledge of widebody powerplants, they’re also helping validate the maintenance manual for the GE9X based on what they learn.

“Every day is something new,” Chieu said.

Where the GE9X engines go, this GE field service team follows, collecting data and ensuring flight-readiness.

Boeing continues to conduct an extensive flight test campaign with a fleet of four 777-9 airplanes. For the engines onboard, the GE team plans maintenance activities, coordinates schedules with Boeing, and collaborates with GE product support engineers to report back new learnings, refining maintenance directions. This includes performing inspections before and after every flight and more detailed inspections on scheduled intervals, a more rigorous process compared to engines already in commercial service.When one of the airplanes leave Boeing Field for a remote location, such as July’s Farnborough International Airshow, the GE team is also responsible for configuring spare parts and tooling to support the trip. The flight test support kit could contain over 400 spare part numbers as the team tries to anticipate potential issues with engines and instrumentation before they happen, ranging from repairing line replaceable units to the more complex.

“My favorite part is seeing the airplane take off every day knowing we’ve done a good job to make sure the engines are ready for a safe operation,” said Ori Berger, a fellow field service engineer responsible for GE9X engines powering another one of the 777-9 test planes.

Each test plane and engine combination has a dedicated GE team, including a maintenance technician and controls software engineer.

As a Flight Test Support Engineer and Instrumentation Focal, Norman Lewis ensures that the engines are airworthy at all times. Lewis also has his FAA Airframe & Powerplant certification, which allows him to execute maintenance activities alongside the flight test engine mechanics, such as borescope inspections and instrumentation troubleshooting. As he watched the airplane takeoff at Farnborough with Chieu, Lewis said he’s reminded of all the team’s hard work going into it.

Top: Members of the GE field service team who maintain GE9X engines walk toward the 777X at the Farnborough International Airshow in July 2022. Above: The Boeing 777X aircraft in flight, powered by two GE9X engines, the world’s largest and most powerful commercial engines. Photos: Alex Schroff

“I love being around and working on airplanes,” said Lewis, who has been working on flight test engine programs for about six years. “The reason I like working on flight test programs is because it allows me to see what goes into engine and aircraft programs certification.”

A monitoring station on each test airplane records data from all flight and engine runs. “We’re the eyes and ears of data coming off the engine, making sure data goes to the appropriate people at GE and Boeing,” said Gunther Beall, controls engineer with GE Research. Part of GE’s Edison Engineering Program, Beall is currently spending a rotation with the GE team at Boeing to support the GE9X. “It’s incredible to see the technology at work, as well as seeing teams from really all around the world come together,” said Beall, about witnessing the Farnborough 777-9 demonstrations flights.

The U.S. Federal Aviation Administration (FAA) certified the GE9X engine in 2020. Designed specifically for the new twin-engine Boeing 777X family, the GE9X is up to 10% more fuel efficient than the GE90 engine.