The Chicago-based company said it has identified two issues with the production of the aircraft that, when combined on the same aircraft, could lead to warping or failure of aircraft parts under extreme conditions.
Boeing said that after discovering that eight planes already in service had these two flaws, “we immediately contacted the airlines. . . to inform them of the situation, and the planes were temporarily taken out of service until they could be repaired ”.
Deliveries of the 787 will be delayed in the coming months, with Boeing carrying out additional inspections to ensure the jets are free from defects.
Neither Boeing nor the US Federal Aviation Administration have released details on the number of jets likely to be affected. Airlines started flying the 787 nine years ago.
The FAA said it “continued to engage” with Boeing and that it was “too early to speculate on the nature or extent of the proposed airworthiness directives that could result from the agency’s investigation” .
Boeing shares fell 5% on Tuesday to $ 162.49.
The FAA investigation is the latest blow to Boeing, which was grappling with the worldwide grounding of the 737 Max following two fatal crashes when the Covid-19 pandemic caused airline passenger numbers to drop .
Airlines are reducing their schedules, especially on international routes used by jumbo jets like the 787, reducing the need for new jets. Boeing delivered four 787s in July, up from 12 a year ago, with customers delaying deliveries.
The pandemic has forced Boeing to reduce its production rate on almost all of its portfolio, as well as 19,000 jobs.
The Dreamliner is produced at factories in Washington State and South Carolina. Washington’s workforce is unionized, while workers in South Carolina are not. With the company expected to produce six 787s per month, up from 10, Boeing decides to continue manufacturing the jet at both locations.
Workers in South Carolina installed the wrong size shims – thin pieces of material used to create a better fit – in the joints between the fuselage sections on some 787s, Boeing said. Furthermore, some airplanes do not meet the technical specifications relating to the flatness of the skin.
Taken as a whole, the defects “result in a condition that does not meet our design standards,” Boeing said. The company said it was looking at “the root cause” that led to substandard products.
The company is also fixing a third issue with the 787’s horizontal stabilizers, the tail structure that prevents the plane from pitching forward. Horizontal stabilizers are manufactured at a plant in Utah before final assembly in Washington or South Carolina.
Workers have tightened parts of the stabilizer too tightly, which could age it prematurely, Boeing said. The company is correcting the issue on planes that are still in production and analyzing if any jets in service also require a fix.
“This is not an immediate flight safety issue because none of the aircraft in service are in a window where they could start to experience this aging,” Boeing said.
Without Max’s crashes, investors likely wouldn’t be concerned about this FAA investigation, said Ron Epstein, a global research analyst at Bank of America. But the investigation, combined with these and other previous issues, will raise questions about the build quality.