Boeing 777X: 5 hurdles left before first delivery

Simple Flying reports that Boeing still targets a first 777X delivery in 2027, roughly seven years after the 777-9 was originally supposed to enter service in 2020. Boeing has absorbed billions in program charges, and the report lays out five hurdles still in the way.

The engine issue

The latest hurdle is the GE Aerospace GE9X, the only engine option for the 777X. Boeing CEO Kelly Ortberg warned in September that some 777-9 certification testing could slip into 2027 because GE Aerospace needed more work to validate a fix for a durability issue with a part called a mid-seal. Boeing's materials from the Morgan Stanley Laguna Conference confirm Ortberg discussed the remaining certification work on Sept. 16.

According to Simple Flying, GE discovered in February that the mid-seal was not durable enough, traced the root cause in April, and redesigned the part. Improved GE9X engines began shipping to Boeing in the third quarter of 2026.

There is a timing disagreement. GE Aerospace CFO Rahul Ghai says the seal problem won't push the 2027 service entry back. Boeing says the added engine work might push part of the testing into 2027. The current mid-seal already passes some certification requirements, Simple Flying notes, but the replacement still needs separate FAA approval before it goes into production engines.

FAA approvals still ahead

The 777-9 has made progress through the FAA's Type Inspection Authorization process. The FAA cleared TIA 4B in the second quarter of 2026, which let another big certification phase begin. By July, the test fleet had passed 4,800 flight hours and about 1,700 flights, with roughly half the planned certification testing complete.

Boeing says almost all Type Inspection Authorizations are done. Still missing are TIA 5 and the approvals tied to ETOPS, the certification that lets twin-engine jets fly long routes over oceans and remote areas. The GE9X work is tied to one of those remaining regulatory gates.

FAA Administrator Bryan Bedford said in May that the 777X comes after the 737 MAX 7 and MAX 10, with the first delivery possibly in early 2027. Simple Flying reports that comment and notes Boeing still officially targets 2027.

Production-standard testing

Boeing now tests jets built to customer standard instead of mostly using dedicated test planes. That matters because an aircraft that finishes development testing is not automatically ready for an airline. Boeing has to show the customer configuration works as a complete product.

Lufthansa's first 777-9 flew for the first time on May 7, a three-hour, 27-minute trip out of Everett with its full passenger cabin on board. Boeing said the plane would then be tested for cabin systems and connectivity on the ground and in the air.

Still to come: functional and reliability checks, operational proving, and the testing that extended operations require. How airlines maintain the jet also gets validated, and that feeds later ETOPS work.

Reworking early-built jets

The long delay created a problem most programs avoid. Boeing built several 777-9s years before the final production configuration was set, and those early planes can't be delivered straight from storage. The company set up a separate effort to update early aircraft, with each one getting its own plan and schedule based on when it went through final assembly, according to Simple Flying.

Boeing has said one of its oldest examples, WH007, built in 2019, was taken apart instead of finished for Emirates. Bringing that jet up to final standards and Emirates' specifications would have cost more than it was worth, Simple Flying reports.

Customer acceptance

At the 2026 Farnborough Airshow, Emirates President Sir Tim Clark said the airline would reject its first 10 or 11 777-9s. Simple Flying reports the reason: the jets are too old and need too many changes. Boeing has set up a separate line to update early-build 777-9s.

Lufthansa is the launch customer, so it should get the first handover. That customer-configured Lufthansa jet has already flown.

For travelers, the practical point is simple: don't expect the 777-9 to carry passengers before 2027. All five pieces, engine approval, FAA sign-offs, production testing, rework and customer acceptance, have to line up first.

• air travel
• Boeing 777X
• Emirates
• FAA
• GE9X
• Lufthansa