Boeing's highly advanced and in demand jetliner is experiencing another delay this time related to a structural issue. Repairing the defects will push back Boeing's delivery of airplanes and adds to the problems that have been plaguing the 787 since it was introduced into service in 2011.

On Friday, March 7, Boeing reported hairline fractures in the wings of a number of planes, according to the New York Times. The defect was highlighted by Mitsubishi Heavy Industries, which manufactures the carbon composite wings in Japan. According to Mitsubishi, a change in their manufacturing process had caused hairline cracks in a limited number of shear ties on a wing rib in the airplane.

Forty-three are affected by the defect, according to the Seattle Times. Boeing has stated that none of the planes have been delivered to airlines and none of the 123 planes already in service are affected. According to Marc Birtel, a Boeing spokesman, said that inspection and any fixes would take about one to two weeks per plane. The Seattle Times reports that source said that Mitsubishi is a high-quality supplier and the fact that they discovered the cracks and reported them proves that.

"As soon as Mitsubishi became aware of the situation, it began inspections to ensure that all the hairline cracks were detected," added Birtel. "They commenced inspections and made changes to the manufacturing process." According to the New York Times, the airplane manufacturer has outsourced about a third of production to Japan and assembles the final products in their factories in Everett, Wash. and North Charleston, S.C.

The cracks, which are no longer than an inch, were discovered in planes that were still in production or the wings had not been delivered yet. Yet, this has not been the only issue with the Dreamliner's wings. According to the Seattle Times, in 2011 many of the new jets had to be repaired after it was found that sealant was leaking into the fuel tank. Although production will be slowed by the cracks, the planes in construction that are not affected will be delivered on time.