The US Federal Aviation Administration (FAA) has formally denied Boeing (BOE, Washington National) permission to move forward in certifying its forthcoming B777-9, currently in its testing phase.

In a sternly-worded letter dated May 13, seen by The Seattle Times, the FAA warned Boeing it might have to increase the number of test flights and that certification, realistically, would probably only happen in late 2023. That would push the aircraft’s service entry to early 2024, four years later than initially planned.

The letter cites multiple concerns with the aircraft, including:

  • an incident during a test flight on December 8, 2020, when the aircraft's nose pitched abruptly up or down without pilot input. Boeing has yet to satisfy the FAA that it fully understood and corrected what went wrong that day;
  • a critical avionics system proposed for the aircraft does not meet FAA requirements;
  • concerns with proposed modifications involving late changes to both software and hardware in the electronics of the jet’s flight controls.

“The aircraft is not yet ready. The technical data required for type certification has not reached a point where it appears the aircraft type design is mature and can be expected to meet the applicable regulations,” wrote Ian Won, the manager of the local FAA office.

An unnamed FAA official, who spoke to The Seattle Times, said the certification delay was getting urgent high-level attention at the FAA and Boeing. “The days of Boeing being able to say to the FAA ‘Just trust us’ are long gone,” he said.

In a statement shared with ch-aviation, Boeing said it "remains fully focused on safety as our highest priority throughout 777X development". "As we subject the airplane to a comprehensive test programme to demonstrate its safety and reliability, we are working through a rigorous development process to ensure we meet all applicable requirements. We continue to communicate transparently with the FAA and other global regulators about 777-9 certification.”

Speaking at a conference on June 3, Boeing President and Chief Executive Officer Dave Calhoun said Boeing was confident the B777X would be certified in the fourth quarter of 2023 but said the manufacturer would abide by FAA timelines. "We will be subject to FAA's timeline, and we will not question it."

He added: "We've incorporated all the timeline learning that we could possibly incorporate from the MAX recertification and the architectural preferences that both the FAA and the EASA have embedded in their regulations. So those are important things with respect to how we do this, and we've incorporated that, and we've given ourselves time to learn as we go through this". Calhoun also said he was satisfied with Boeing's progress with the aircraft and that the aircraft was performing well during test flights.

Boeing’s last all-new jet, the B787 Dreamliner, was grounded in 2013 after its batteries began smouldering in flight. Its B737-8 MAX was grounded for 21 months starting in 2019 after flawed new flight controls caused two fatal crashes in Indonesia and Ethiopia.