The U.S. Federal Aviation Administration (FAA) has cleared the Boeing 777-9 to begin Phase 4A of its Type Inspection Authorization (TIA), marking another step in the certification of the long-delayed widebody. The development was first reported by The Air Current and later confirmed by Boeing.
The approval enables the planemaker to start a new series of air and ground tests aimed at demonstrating compliance with U.S. regulations. Speaking at an investor conference, Boeing CFO Jay Malave said the company expected authorization to proceed “very shortly,” a timeline that has now materialized.
Phase 4 is divided into two segments, 4A and 4B, and together they represent a volume of testing comparable to Phase 3, which began in November 2025. Certification phases can overlap across multiple aircraft, and progress into a new stage does not require earlier phases to be fully completed.
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The final Phase 5 is expected to involve a smaller set of tests before the program moves into extended operations (ETOPS) and function and reliability trials, which are typically conducted with aircraft configured for delivery.
The 777-9 is the first and largest variant of the 777X family and the biggest twin-engine passenger jet developed to date, with capacity exceeding 400 passengers in a typical two-class layout. The program remains several years behind its original schedule, with entry into service now expected in 2027.
As of the end of February, Boeing had accumulated 624 orders for the 777X family, including 521 for the 777-9, 68 for the 777-8 Freighter and 35 for the 777-8 passenger variant.
