Boeing's Dreamliner Struggles: Surprise or Predictable?

July 23, 2009

6 Min Read
Boeing's Dreamliner Struggles: Surprise or Predictable?

Now in the midst of yet another delay with the Dreamliner program, Boeing's reputation is on the line as they work through a vexing situation.

The latest problem with the Dreamliner is engineering related but it's also political. Technical issues forced the cancellation of the airliner's First Flight, and when an aerospace company has to cancel something as high profile as First Flight, it's a very bad thing: Bad for the program, the bottom line, the company's reputation and bad for the morale of those involved with the program.

In a nutshell, the technical issue forcing the postponement of First Flight has to do with the two huge composite sections used as attach points for the wings on the 787. The first, the Wing Box, is manufactured by Mitsubishi and the second, the Center Wing Box, is manufactured by Fuji.

These parts are joined together to provide a secure mounting structure for the wings, which are affixed to the assemblies at points on each side of the fuselage. Reinforcing stringers provide additional strength for the structures. The stringers are integrated into the composite material, which is then cured in an autoclave.

Unfortunately, the areas of the two assemblies where the reinforcing stringers meet, called stringer caps, sustained damage when the wings were flexed in a test conducted in May. This in turn caused some small sections of the wing structure itself to disbond.

For awhile, Boeing thought it could still accomplish the First Flight using a less aggressive flight profile but at the last moment decided to not take the chance. It was the right thing to do, but Boeing has paid a hefty price for that decision on the Public Relations front.

The two assemblies will now have to be redesigned and tested. For the six test aircraft already in existence, fixes also will have to be designed, installed, and tested. The wing static load tests will have to be performed again to make certain the wing can flex to the required 150% of design load without structural failure of the wing itself or damage to the join areas. The company is admitting to several weeks delay before a new First Flight date is specified. But it's probably more like several months.

Unfortunately, Boeing cannot take advantage of its large library of technical information derived from composite structure military projects to reduce the time. The reason is something called ITAR, which stands for International Traffic in Arms Regulations. The Dreamliner project is such a large, multi-national program that special permission would have to be granted by the Federal Government for Boeing to use military-derived technology and that would mean even more delays.

Meanwhile, the company has completed low speed taxi tests on the first test article and has run it through a series of tests. Called "The Gauntlet," these tests check each and every system needed for operation of the airplane including the emergency regimes. Now the wait begins for resolution of this newest problem.

So what does all this mean for the project and the ultimate success of the 787 Dreamliner program?

It's a Boeing goal to solve every technical issue before the first airplane is delivered because the company doesn't want its airline customers serving as sustaining engineering partners and neither do the airlines.

But trying to develop a predictive design tool that can identify and highlight every point where stress can accumulate in a huge airborne composite structure--and accurately predict the magnitude of each stress load under all flight conditions--is probably a fool's errand. The sheer number of combinations of potentially additive stress points between components most likely precludes the possibility, at least in a commercial venture with a budget that is not unlimited.

That's why the 787's testing procedures are so rigorous and detailed. Given that you can't always predict potential structural failure points, you'd better be able to discover them during testing. So far it seems that Boeing's testing program is working well. But each time a problem is discovered, people who do not understand the process put another black mark next to Boeing's name.

There's one area, though, where Boeing may have erred: The company may have lost control of a portion of its engineering oversight, an area where even Boeing's staunchest proponents have not been particularly happy. The consensus is that it's difficult enough to successfully design and manufacture something as complex as an all-composite airliner, let alone making the decision to outsource some of the engineering oversight. Industry rumors are circulating that Boeing has started pulling the engineering control back inside the company.

So where does Boeing go from here, and how does it recover from the setbacks and false starts?

It's a binary problem: If Boeing can overcome these latest issues and deliver an airliner with no design shortcomings and few glitches, they'll retain their fat order book and be the recipient of additional orders from those still on the sidelines. But should more problems occur and the delivery schedule continues to slip, orders will be cancelled and Airbus will be the beneficiary.

There is some good news, though. In a vote of confidence, All Nippon Airways, the 787 launch customer, increased its initial order from 50 to 55 airplanes. The increase came within days of Boeing postponing First Flight. But at the same time, ANA demanded Boeing provide a detailed plan for avoiding more surprises and a realistic estimate of when ANA will get their first airplane.

In a way, ANA's request is a snapshot of a bigger problem Boeing is dealing with: The airlines and the public are not plugged into the arcane world of aerospace design. Neither group wants to think about a problem surfacing during testing because that means the original design wasn't perfect.

It's an unrealistic view but it's the way things are for companies like Boeing. They have to finesse this mindset, yet be very careful never to ignore a potential problem--no matter how much bad press the situation might bring.

John Loughmiller is an EE, Commercial Pilot, Flight Instructor and a Lead Safety Team Representative for the FAA.

Boeing 787 Dreamliner First Flight: A Chronology of Delays

July 8, 2007 

At the premier, Boeing announces First Flight of the 787Dreamliner is scheduled for Aug/Sept 2007

Sept 5, 2007

Boeing announces a three-month delay, blaming a shortage offasteners as well as incomplete flight control software

October 10, 2007

Boeing announces a second,three-month delay, citing supply chain issues leading to parts shortages

January 16, 2008

Boeing announces a third, three-month delay, blaming slowwork from suppliers

April 09, 2008

Boeing announces a fourth delay, this timefor six months, citing traveled work and unanticipated rework

Dec 11 2008

Boeing announcesa fifth delay, to the second quarter, blaming the 58-day machinists strike and"fastener replacement work."

June 15, 2009

Boeing announces that the Boeing 787 will make its First Flightwithin two weeks

June 23, 2009

Boeing postpones First Flight, citing modifications to theside-of-body section of the aircraft. The problem was identified during testson the full-scale, static test airplane.

Sources: Boeing, Flight Global, Design News

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