Inside GE Aerospace’s Boeing 747 ‘Flying Laboratory’ for Testing Jet Engines

GE Aerospace is using a specially modified Boeing 747-400 as a Flying Test Bed to test and prove new commercial jet engines. The aircraft was bought from Japan Airlines in 2010 and replaced an older Boeing 747-100 that GE had used since 1992. Its latest major assignment is testing the GE9X, the engine being developed for Boeing’s yet-to-be-certified 777X.

The 747’s cabin has been transformed from passenger space into a testing environment packed with cables, sensors, computer stations, and large data-collection boxes. Business Insider reports that thousands of feet of wiring run through the aircraft, connecting equipment that gathers large amounts of test data. The setup turns the dual-level jet into a self-contained platform for measuring engine performance in real flight conditions.

The GE9X is described as the world’s largest jet engine and is large enough to fit an entire Boeing 737 fuselage. It is rated for 110,000 pounds of thrust and reached 134,300 pounds during testing, a world record for the highest thrust recorded by a commercial jet engine. The engine received FAA certification in 2020 but continues to undergo additional testing for the 777X program.

The flying testbed has helped certify engines used on aircraft including the Airbus A320, Boeing 737, and China’s Comac narrowbody. For Boeing’s 777X, the GE9X testing program remains important because the aircraft is seven years behind schedule, with delays linked in part to quality, production, and supply chain issues at Boeing. Business Insider reports the 777X is expected to enter service in 2027 with Lufthansa.