New 787 Dreamliner production issue could slow delivery of 90 jets in Boeing's inventory

By Valerie Insinna

WASHINGTON, June 6 (Reuters) - Boeing said on Tuesday it is slowing deliveries of its 787 Dreamliner after the company discovered a new production flaw, but expressed optimism that it can still deliver 70-80 of the widebody jets this year as planned.

The problem, which does not pose a flight safety concern, involves a fitting for the 787's horizontal stabilizer made by a Boeing production facility in Salt Lake City, Utah, the company said. Boeing will need to inspect all 90 Dreamliners in its inventory before they can be delivered, and it expects it will take two weeks to fix each aircraft, the company added.

Boeing said it found last week that the fitting used 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 deliveries of 787s suspected to have the flaw, the company said.

The issue does not immediately impact 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.

"We have notified the FAA and our customers and are keeping them informed of our progress," Boeing said in a statement, referring to the U.S. Federal Aviation Administration.

While the rework "will affect timing of near-term 787 deliveries," the company believes it can still deliver 70-80 Dreamliners this year, Boeing said.

The announcement of the new issue comes as Boeing grapples to recover from a 737 bracket installation issue disclosed in April, which slowed deliveries of the cash-generating family of narrowbody jets, including the bestselling MAX 8 model.

Although not a safety issue, Spirit AeroSystems had improperly attached two of the eight brackets that connect the vertical tail to the back of the fuselage, which Spirit makes in Wichita, Kansas.

Boeing CEO Dave Calhoun in April called the problem a "gnarly defect" that was nearly impossible for workers to visibly assess. The company said last month it had begun delivering reworked 737s.

Boeing, which last week announced that it had increased 787 production from three to four jets a month, has also struggled with recent supplier issues on the Dreamliner.

The FAA temporarily stopped 787 deliveries in February after Boeing found a data analysis error related to forward pressure bulkhead. In March, the FAA announced it would allow Boeing to restart 787 deliveries, as the U.S. planemaker had addressed concerns.

(Reporting by Valerie Insinna in Washington; Editing by Will Dunham)