Boeing to Inspect Wings of Undelivered Dreamliners for Cracks: Plane Maker Says Manufacturing Defect Could Cause Delays in Delivering the Jets

The Wall Street Journal
By  Jon Ostrower
 
Updated March 7, 2014 4:14 p.m. ET


Boeing Co.  and a key supplier are inspecting the wings on 42 yet-to-be-delivered 787 Dreamliner jets after discovering hairline cracks caused during manufacture and prompting the aerospace giant to delay deliveries to some airlines.

The defect is a major headache for Boeing, which has boosted output after years of delays and is working to maintain production this year of 10 Dreamliners a month. The company still plans to deliver around 110 of the jets in 2014 and said its revenue guidance for the year remained unchanged.

The wings are made by Japan's Mitsubishi Heavy Industries Ltd, which told Boeing that a change in its manufacturing process may cause the cracks, according to a spokesman for the U.S. company. Subsequent inspections revealed cracks on some jets.

The inspections and repairs at Boeing plants in Washington state, South Carolina and Mitsubishi facilities in Japan illustrate how manufacturing problems can be spread quickly through the supply chain while it builds Dreamliners at a record rate.

Last year, Boeing halted 787 deliveries due to problems with the jet's lithium-ion batteries. Global regulators grounded the Dreamliner for about three months until the company could find a way to safely contain the battery in the event of a failure.

Boeing said none of the 123 Dreamliners delivered to date are affected by the wing issue. The company was told by Mitsubishi in the second half of February of the issue after its routine quality checks, said a person familiar with the matter.

Boeing has accelerated production to meet high demand for the more-fuel efficient aircraft, and Boeing expects to add 17 new customers of the jet in 2014, including American Airlines Group Inc., Air Canada and Kenya Airways. "We will work with customers to adjust delivery schedules as required," said a spokesman.

Boeing and its partner are inspecting 787s with line numbers running from 151 to 193, representing around a fifth of all Dreamliners built since 2007, according to the same person familiar with the issue.

The latest problem to affect the Dreamliner program stems from fasteners used to connect aluminum shear ties on the wing ribs to the carbon fiber composite wing panel, according to two people familiar with the situation.

The fasteners were over-tightened without the use of manufacturing fillers, compressing a gap in the structure and in some cases caused hairline cracks of less than an inch. If left unchecked can cause unintended stress on the jet's structure and could lead to further damage.

"We understand the issue, what must be done to correct it, and are completing inspections of potentially affected airplanes. We are addressing affected airplanes as required," said the Boeing spokesman.

The manufacturing defect is a rare significant quality defect for Mitsubishi, whose quality control has traditionally been a model for Boeing to emulate inside its own factories. The Japanese company wasn't immediately available for comment.

A Boeing supplier in Italy made a similar manufacturing error that was discovered in 2010 when assembling horizontal tails for the Dreamliner, requiring significant work on dozens of aircraft.

Mitsubishi builds the carbon fiber composite 787 wings at its Nagoya, Japan factory before they are shipped by a heavily-modified 747 jumbo jet to Boeing's final assembly lines in Everett, Wash. and North Charleston, S.C. Japanese suppliers build 35% of the Dreamliner, the first jetliner to be made from a majority of carbon fiber composites

Boeing said it expects each jet will take one to two weeks to inspect and correct, depending on its position in the production process. About 17 of the 42 aircraft are fully completed and seven have been undergoing pre-delivery flight tests, according to external sources tracking the program.

The rest of the 787s are in various states of assembly, or the wings are still in Japan and have yet to be shipped for final assembly.

The company said its 2014 revenue target of $87.5 billion to $90.5 billion remains unchanged and it still plans to deliver 110 787s this year. However, deliveries planned for the first quarter could slip beyond March, the close of the company's first quarter.

Separately, Airbus Group NV on Friday said it was recommending airlines inspect the wing spars on earliest A380 superjumbo jetliners delivered at six and 12 years after delivery. The company had found potential cracking as part of a structural fatigue test that stresses the aircraft more than three times its expected lifetime in service. The earliest A380s, now over six years old, have already been inspected with no findings, an Airbus spokesman said. 

Source:   http://online.wsj.com