DALLAS – Boeing has recommenced flight testing of its 777X airframe after a two-month break due to unspecified technical issues with its General Electric GE9X engines.
The manufacturer confirmed that flight testing with airframe N779XW restarted on December 17. Boeing currently has four 777-9 prototypes carrying out the rigorous testing program, which began in January 2020.
Previous Engine Issues
This is not the first time General Electric has had issues with the GE9X. The first flight with the power plant had been scheduled for February 2018, but problems with the high-pressure compressor and engine durability led to delays of six months.
The latest issues, GE said, had affected the engine that had been used the most in testing – over 1,700 hours of run time and over 2,600 flight cycles. The results of a borescope inspection highlighted a fault in the flight test engine temperature sensor.
The 777X
The 777X program has been in development since 2013. Currently, only the -9 has been built. Boeing has also proposed a shorter, longer-range -8 and a stretched -10X to compete with the Airbus A380.
However, the aircraft has encountered numerous delays, which has now pushed back the jet’s entry into service until 2025 from a previous target of 2023. It also faces tough certification scrutiny from the US Federal Aviation Administration (FAA). The FAA has told Boeing that it will not certify the aircraft until later next year and has concerns regarding a lack of data and a preliminary safety assessment.
Featured Image: The aircraft has returned to the skies after two-months. Photo: Brandon Farris/Airways.