Another test model of Boeing’s much-anticipated 777X took flight last week after a hiatus lasting nearly half a year on the ground. The 777-9, along with three other pre-series models, have performed test flights since 2020 but have experienced some challenges.The model, N779XX, returned to the skies almost a month after its sister model, N779XW, resumed its test flights after a two-month pause to resolve engine issues. Although Boeing hopes to start delivering the aircraft to carriers in two years, hurdles that have come about in the certification process may push deliveries back.

Another model back in the sky

According to Aviacionline, N779XX is the second 777X test model to be produced. It took off from King County International Airport (BFI) in Seattle, known as Boeing Field, on Friday, January 13th, joining N779XW in the certification process.

Data from FlightAware showed that N779XX departed BFI at 11:46 and flew for nearly two hours. The aircraft reached a cruising altitude of 37,000 feet and a speed of 552 miles per hour (mph). It reportedly performed two approaches, briefly diverting to Grant County International Airport (MWH) in Moses Lake, Washington, before returning to BFI.

According to a news sharer on Twitter, the flight was a preliminary test for the aircraft’s flight controls, which is typical after not flying for long periods. The plane last flew on August 14, 2022.

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Four test aircraft, but only two are in the air

Boeing developed four pre-series models of the 777X: N779XW, N779XX, N779XY, and N779XZ. According to Aviacionline, N779XY was grounded in July, while N779XZ only made one flight in 2021 and did not take off again. N779XW resumed flights in December after being grounded for two months.

It is also rumored that the two remaining test aircraft will return to the skies later this year. According to the news sharer, N779XY is expected to resume test flights in April, and N779XZ is scheduled to return to testing in July. Simple Flying has reached out to Boeing for confirmation of this news.

The manufacturer reportedly has a fifth test 777X that was intended to be used to test the aircraft’s interior and exterior, but there is no sign of whether it will be used. The goal of returning the four primary test aircraft is to reach Type Inspection Authorization (TIA), which enables Federal Aviation Administration (FAA) experts to get onboard and start final certification, according to the news sharer.

UPDATE: 2023/01/16 14:27 EST BY CHANNING REID

Statement from Boeing:

"We don’t provide forward-looking information about our flight-test schedules." - Jim Proulx, Spokesperon, Boeing Commercial Airplanes

An enlarged engine comes with challenges

The 777X is equipped with the new GE9X engines, which are the largest aircraft engines in the world. During its certification process, test flights have been performed to ensure the engines and technology are running correctly and safely. The recent groundings due to engine issues have concerned some airlines about the timeline of the deliveries.

Dubai-based Emirates has patiently awaited the certification of the new aircraft as it exclusively operates widebody planes. The carrier is keeping older, less efficient Airbus A380s to maintain its operation and capacity. Tim Clark, Emirates CEO, said the airline is not expecting its first 777X to arrive until at least 2025.

Source: Aviacionline

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  Boeing

  Stock Code:

  BA

  Date Founded:

  1916-07-15

  CEO:

  Dave Calhoun

  Headquarters Location:

  Chicago, USA

  Key Product Lines:

  Boeing 737, Boeing 747, Boeing 757, Boeing 767, Boeing 777, Boeing 787

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