US aircraft manufacturer Boeing has discovered a manufacturing error causing delamination in a fuselage section of some 787 Dreamliners, The Seattle Times reported on Sunday.
Citing an unnamed person with knowledge of the problem, the newspaper said Boeing was inspecting all the airplanes already built to determine the extent of the problem.
Boeing has completed assembly of about 50 Dreamliners to date and has delivered five to All Nippon Airways of Japan.
The plane entered service last year after more than three years of delays. In a brief statement, Boeing said that the unspecified damage resulted from 'incorrect shimming performed on support structure on the aft fuselage of some 787s.'
Mechanics install shims, or spacers, to fill small gaps that occur between parts that don't fit together exactly, The Times explained.
A problem with faulty shimming arose in 2010 in Italy, the paper noted. Mechanics at a plant there applied too much torque when tightening fasteners, and the consequent compression of the shims degraded the composite material.
At that time, those manufacturing quality issues with the horizontal tails added months of delays to the jet program, The Times said. Many airplanes had to have their tails extensively reworked.