WASHINGTON, (Reuters) – Boeing said on Tuesday it could be forced to slow deliveries of its 787 Dreamliner after the company discovered a new production flaw that will require it to inspect all 90 jets in its inventory, the latest in a series of setbacks for the widebody plane.

While the newly-found production hiccup does not pose a flight safety concern, it follows an month-long 787 delivery stoppage that was resolved in March and adds yet another delay for Boeing as the U.S. planemaker struggles to rework the planes before they can be delivered to customers.

The problem involves a fitting for the 787’s horizontal stabilizer installed by a Boeing production facility in Salt Lake City, Utah, the company said. The horizontal stabilizer, located at the base of an aircraft’s tail, allows a plane to maintain longitudinal balance while flying.

Boeing will need to inspect all 90 Dreamliners in its inventory before they can be delivered, and expects it will take two weeks to fix each aircraft, the company added.

The manufacturer said it found last week that the fitting included shimming – a material that fills gaps between the surfaces of an aircraft – that was improperly sized and did not meet specifications. On Friday, it stopped approving 787s suspected to have the flaw for delivery, the company said.

The issue does not immediately affect in-service 787s, Boeing said, but the company could not say how far back the issue stretches or whether Dreamliners currently operated by airlines will need a fix.

Boeing, which announced last week that it had increased 787 production from three to four jets a month, said the issue has not caused a halt in 787 production.

“There should be minimal production disruption given conforming shims require only minor changes,” Jefferies analyst Sheila Kahyaoglu said in a note to clients.

Boeing shares, which fell 2.4% immediately after the defect was announced, closed 0.7% lower on Tuesday.

The U.S. Federal Aviation Administration said in a statement it had validated Boeing’s assessment that there was no immediate safety issue for 787s already in service.

The agency, however, said it would not issue any new airworthiness certificates for the 787 until the matter was addressed to its satisfaction.

Reuters
Photo Rob Vogelaar