Boeing’s stockpile of undelivered 787s has swelled in recent weeks as the company addresses quality issues determined to be more widespread than initially suspected.

The Chicago airframer now holds 60 undelivered 787s, up from 40 two months ago and from 31 in late July, according to Cirium fleets data.

Those jets have made first flight but have not been delivered.

The increasing stockpile comes as Boeing confirms it identified additional quality issues with 787 fuselages. Related inspections have slowed deliveries to a crawl.

Boeing 787-10. Boeing

Source: Boeing

Boeing 787-10

“We have identified other areas of the fuselage join… with the skin-flatness issue. This did not meet engineering specifications,” Boeing says. “Engineering analysis… [has] shown this not to be a safety-of-flight issue”.

The Federal Aviation Administration agrees.

“None of the issues raised recently are considered to be immediate safety concerns,” the agency says. “Nevertheless, the FAA takes these quality concerns seriously and continues to be involved in the discussions about any mitigations.”

Several months ago, Boeing identified the skin-flatness issue at 787 “aft-body fuselage joins”, it says.

Asked to elaborate, Boeing says it “discovered that some areas of the 787 circumferential fuselage join may not meet specified skin-flatness tolerances”.

Those tolerances are “five one-thousandths of an inch – no wider than the width of a human hair”, it adds.

The issues have led Boeing to inspect aircraft coming off its assembly lines in Everett and South Carolina, “to ensure these meet our highest quality standards”.

The inspections have slowed deliveries, as has the coronavirus pandemic and related travel restrictions, Boeing has said.

During a 4 December Credit Suisse conference, Boeing chief financial officer Greg Smith said inspections were “taking longer than we previously anticipated”.

The airframer delivered no 787s in November, and has handed over just 17 of the jets since July, Boeing’s data shows.

“We have strengthened our quality assurance programme over the last 12 months, and in doing so identified certain items on assembled 787 airplanes that we are taking time to inspect and correct as necessary,” Boeing tells FlightGlobal. “These inspections will result in slowed deliveries for the remainder of the year, and we anticipate unwinding the inventory of undelivered airplanes throughout 2021.”

The Seattle Times reported that the issue has also spurred inspections at 787 suppliers, including Wichita’s Spirit AeroSystems, Italy’s Leonardo and Japan’s Kawasaki. Those companies all make 787 fuselage sections.

The Times’ report suggests the issue involves manufacturing of the composite sections.

Boeing declines to confirm if suppliers are also inspecting components.

“We are working with suppliers to assess this issue. And as explained, we are inspecting undelivered airplanes and will meet all requirements before delivery,” Boeing says.