Boeing said Friday it was working to address questions about its 787 Dreamliner from US air safety regulators after again suspending new deliveries of the jet.
The questions concern the inspection method for new planes following production problems that led to an earlier pause in deliveries. With approval from the Federal Aviation Administration (FAA), Boeing had resumed deliveries of the widebody Dreamliner in March after a five-month halt.
"Boeing still needs to show that its proposed inspection method would meet FAA's federal safety regulations," the agency said. "The FAA is waiting for additional data from Boeing before determining whether the company's solution meets safety regulations.
"Since the FAA has not approved Boeing's proposal, Boeing chose to temporarily stop deliveries to its customers."
A Boeing spokesperson said there was no impact on 787 planes already in service.
"We are working to provide the FAA with additional information concerning the analysis and documentation associated with the verification work on undelivered 787s," a Boeing spokesperson said.
"We continue to work closely with the FAA in a transparent and timely manner."
The latest suspension concerns Boeing's proposal for a statistical analysis of data that allows for more narrow reviews, The Wall Street Journal said, citing people familiar with the matter.
Until the agency's questions are satisfied about more targeted inspections, the FAA is requiring Boeing to undertake broad inspections that are time-consuming and labor-intensive, the newspaper reported.
The Journal also described a number of quality issues, including gaps where the plane's body joins together.
Boeing has described this year as "inflection point" for the aviation industry, with its recovery hopes boosted by Covid-19 vaccinations after the pandemic devastated travel demand in 2020.
The company's prospects have also improved since the FAA cleared the 737 MAX to resume service in November after a 20-month grounding following two fatal crashes.
But Boeing's recovery has hit speed bumps due to production interruptions on both the MAX and the Dreamliner.
Boeing had halted deliveries of the MAX for about six weeks this spring due to electrical problems discovered during the manufacturing process.
The company resumed deliveries earlier this month after the FAA approved the company's fix for the issue.
Shares of Boeing fell 1.9 percent to $246 in morning trading.