Manufacturing defects are creating hairline fractures on the wings of several dozen Boeing 787 Dreamliners, a problem that signals more headaches for the airplane manufacturer less than a year after safety regulators around the world grounded all of the 787s in operation over the risk of battery fires.
The good news is that the problem so far is limited only to planes in various states of production and affect none of the 123 Dreamliner jets currently in operation around the globe. According to the Wall Street Journal, the cracks were discovered by Mitsubishi Heavy Industries, which Boeing contracted to manufacture the Dreamliner wings at its facilities in Nagoya, Japan.
Mitsubishi alerted Boeing to the problem, saying that it was caused by a “change in the manufacturing process.” An inspection of the planes worldwide found that the defect affects 43 jets located at the Mitsubishi plant in Japan and Boeing facilities in Everett, Wash., and North Charleston, S.C.
The cracks stem from fasteners used to attach aluminum sheer ties on the wing ribs to the carbon-fiber wing panel. The fasteners were over-tightened, squeezing a gap in the wing structure and causing hairline cracks around the fasteners. Left unfixed, the defect could stress the structure of the airplane and promote further damage.
The problem throws another wrench in Boeing’s delivery schedule for the Dreamliner. The manufacturer has ramped up its production schedule to 10 787s per month to meet demand for the popular airplane, whose significantly lighter body weight significantly reduces fuel consumption and costs.
Last year, however, Boeing had to halt production of the Dreamliner for three months while engineers scrambled to fix the lithium-ion batteries in the jets, which had overheated and created a fire in some of the planes, prompting a worldwide grounding of all Dreamliners in operation.
The Federal Aviation Administration (FAA) said it was working with Boeing to “ensure that the issue is corrected before the airplanes are delivered.”
According to the Wall Street Journal, a Boeing supplier in Italy made similar production error in 2010 that affected the horizontal tails on dozens of aircraft.