GE9X Engine Nears Final Certification Tests

Engineers at GE Aviation are preparing for final certification tests of the GE9X, the most powerful jet engine in the world.

According to GE Aviation, the final engine certification test, which is called the Initial Maintenance Inspection (IMI), will begin “soon”. The IMI test proves the engine can operate properly within its defined maintenance intervals, the maximum time an engine should be operated for before maintenance is conducted.

GE also needs to complete 3,000 cycles of the Extended Operations (ETOPS) test before entry into service. The outcome will provide eligibility for the GE9X engines to be installed on an ETOPS aircraft.

ETOPS aircraft are permitted to fly remote routes that contain points more than 60 minutes away from the nearest airport, as flown at its one-engine inoperative cruise speed. The GE9X needs to be ETOPS approved so it can be used on the Boeing 777X for its entry into service, which is expected to happen next year.

GE has also recently shared the results of the Endurance (Block) Test with regulatory agencies, Boeing and 777X airline customers.

The Block Test comprised of a progression of 11 different cycle types to mirror what an engine experiences in the field. This endurance test is seen as more representative of both creep and related failure modes.

During testing the engine was subjected to 35% more time at redline temperatures and speeds than FAA requirements to provide proof of the engine’s durability. After the test a piece part inspection was carried out and showed that all the hardware conformed to the certification and manual requirements.

An independent vibration endurance test, which used vibration levels of 33% more than was required, has also recently been successfully completed.

GE Aviation added that 99% of all GE9X engine certification documentation has been submitted with 93% approved by aviation authorities.