Boeing confirms it has halted flight testing of its entire 777-9 test fleet after detecting a failure of an engine-related structural component, a setback for the widebody jet’s already delayed certification program.
Industry publication The Air Current reported on the grounding of the test fleet on January 19, saying that Boeing had discovered a “severed thrust connection” on the test 777-9 aircraft, designated WH003. Boeing only discovered the defect after the aircraft had taken off from Hawaii.
“During a scheduled maintenance check, we discovered a component that was not functioning as designed. Our team is replacing the part, gathering all of the knowledge about the component and will resume flight testing when ready,” Boeing said.
The company describes the defective part as a “structural component between the engine and the aircraft structure” and adds that this component only applies to the 777-9.
Each of GE Aerospace’s two 105,000-pound (467 kN) GE9X turbofans has two of these components, “so there is redundancy,” Boeing says.
“We are checking the test fleet for this condition. For the other test aircraft, for which maintenance and decommissioning work is planned, no test flights are planned in the short term,” the company adds.
According to Air Current, Boeing has also identified the problem on other 777-9 test aircraft. The company’s test fleet includes five aircraft.
Boeing has not commented on how the error might affect the 777-9’s certification schedule. The company aims to put the jet into service next year.
Neither the Federal Aviation Administration nor GE Aerospace immediately responded to requests for comment.
The 777-9 program has experienced numerous delays, some of which were due to Boeing having to make design changes due to increased scrutiny by the FAA.
Boeing only began the certification flight test campaign for the 777-9 in July.
