GE9X mid-seal fix emerges as gating item for Boeing 777-9 ETOPS certification

A durability issue with the mid-seal component in GE Aerospace’s GE9X turbofan is holding up Boeing’s extended-range certification path for the 777-9, according to comments from both companies at a Morgan Stanley investor conference in mid-September.

Boeing chief executive Kelly Ortberg told investors that the Federal Aviation Administration (FAA) will not authorise the 777-9’s ETOPS — extended-range twin-operations — flight-test campaign until it receives GE’s certification plan for the redesigned mid-seal. ETOPS approval governs how far twin-engine aircraft may fly from diversion airports, a requirement for the oceanic routes the 777-9 was designed to serve.

“We still do not have ETOPS authorisations… That’s related to the mid-seal issue we’ve got with the engine,” Ortberg said, adding that he expects the certification plan “very soon” but acknowledged the timing presents “a little bit of a challenge” before year-end.

The issue is not new: Boeing disclosed it in January. GE has said the original part, which links the front and rear sections of the engine and balances power between turbine stages, proved less durable than expected. The company redesigned the component and says the FAA’s testing of the fix should conclude in the coming months. GE chief financial officer Rahul Ghai said the redesign has already been incorporated into production, with updated GE9X engines delivered to Boeing beginning this quarter, and expressed “a huge degree of confidence” in the change.

Sequencing nuance between the two companies

While Ortberg framed the mid-seal certification plan as a prerequisite for ETOPS flight testing, Ghai offered a different distinction: the ETOPS certification itself does not require the new mid-seal, since the existing part functions — that was always the plan, he said. The redesign addresses long-term durability rather than immediate airworthiness.

Boeing had planned to begin ETOPS flight tests after achieving the 777-9’s type certification, which Ortberg said is progressing well as the company works through the flight tests required under the type inspection authorisation (TIA). Despite the engine issue, he reiterated Boeing’s target of first 777-9 deliveries in 2027. 777-9 vice-president Terry Beezhold said in June the aircraft will enter service with a 180-minute ETOPS clearance.

Ortberg separately cautioned that a potential strike by engineers represented by the Society of Professional Engineering Employees in Aerospace (SPEEA), with whom Boeing is negotiating a new four-year contract, could also disrupt the 777-9 timeline.

Shares of GE Aerospace closed at $325.48, down 2.98% from the prior close of $335.49, valuing the company at roughly $337.7 billion.

Source: original release

What to watch

• GE’s submission of the mid-seal certification plan to the FAA, and FAA approval of Boeing’s ETOPS flight-test programme
• Completion of FAA testing on the redesigned mid-seal, expected within the next few months
• Progress on 777-9 type certification flight tests under the TIA
• Outcome of the SPEEA contract vote and labour negotiations
• Boeing’s 2027 first-delivery target as milestones are confirmed or revised