Boeing 787 (partie 1)

The 787 program has faced so many delays, they do not feel like a surprise anymore. At this point, it would be a surprise if there are no more surprises.

Le text qui suit remonte au début du mois de septembre, 2008 !
[quote="sevrien"]Bonsoir, chers tous ! ...............

Je ne veux pas appuyer mon point de vue. Mais il est sincère. J'y ai beaucoup réfléchi ! Prenons du recul ! Ne jetons pas la pierre vers Boeing (Boeing n'est pas BCL & Co. ) ! Car nous avons besoin de la réussite de cette famille B787, même si je pense sincèrement que les modèles présentés en ce moment sont trop petits.

Boeing a fait un marketing trop ambitieux. Les dirigeants de l'époque ont cru au projet, mais ont sous-estimé les difficultés des conception, construction et gestion du "supply chain" (je pourrais écrire 30 pages, .. denses, ... à ce sujet ! Passons).

[quote="sevrien"]Tout le monde voulait y croire, et y croyait (ingénieurs, chercheurs, clients et fournisseurs, .. Boeing ... et même des 'silencieux" chez Airbus, qui voulaient un catalyseur vers de nouveaux concepts et de nouvelles générations d'avions).

sevrien a écrit:La remarque suivante est neutre, mais difficile à faire de façon 'soft'! Tout le monde semble négliger ou oublier un aspect important, qui a été sous-estimé chez Boeing, peut-être même quelque peu 'négligé', dans la "Commercial Airplane Division":
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-- manque (momentané) de disponibilité de talents et compétences, bref, de ressources managériales "maison", en matière de lancement & de gestion d'un projet de "bringing to market" (depuis la conception jusqu'aux premières livraisons ) d'un tout nouveau programme d'un tout nouvel avion.

sevrien a écrit:C'est un facteur 'basic', qui ne convient pas forcément à la façon de penser et 'd'intellectualiser les problèmes' en France. Mais, il faut faire un peu de "back to basics" (retour à la case 'départ'). Pas très sexy comme facteur ! Juste du 'bon sens paysan',...bien plus important que les "business logic" & "modèles" qu'on apprend à nos petits génies des Campus!

sevrien a écrit:Tous les artisans, "pères" et "managers" du projet B777 (bien mené par de nombreux acteurs, ayant déjà participé au projet B747...) avaient quitté Boeing. Ils étaient décédés, ou à la retraite et incontactables, ou indisponibles pour le service (tout le monde n'est pas Joe SUTTER! ). Et puis, ... ce fut la vague BASELER & Blog ! Bref : insuffisance de planning et de 'profondeur' en matière de "Management Succession" !

sevrien a écrit:A l'intérieur et à l'extérieur de Boeing, beaucoup de gens ont oublié, ou n'ont jamaisu, à quel point Boeing et Al MULALLY ont souffert, dans la boue laissée par Mr. WOODARD, après la guerre des prix ridicule entre Boeing et Airbus sur les monocouloirs (familles A320 & B737NG). L'action de WOODARD & Co avait :
-- laissé Boeing exsangue sur le plan de la trésorerie (d'où l'intervention de GE, et l'exclusivité GE90-115B / -110B, sur le projet B777-300ER / -200LR),...
-- et créé une pagaille noire chez les fournisseurs (réfléchir au projet B787 ! ).

sevrien a écrit:Je soupçonne qu'AL MULALLY ait vu se profiler les mêmes types de risques sur B787, surtout quand les commandes commençaient à rentrer par pelleté ! Al MULLALY n'était surement pas un homme amer ! Il n'avait pas eu le job de CEO ! Il a vu l'arrivée de J. McNERNEY !

Il a dû se dire : "Oh, oh ! Si la m.... se met dans le ventilateur, ce n'est surtout pas JM qui va se retrousser les manches ! J'ai déjà donné !" Il a fini par devenir CEO du Groupe FORD Motor, et a pu y aller, en prenant sa retraite (mécanisme à l'américiaine) de chez Boeing !

sevrien a écrit:Enfin, il a fallu que Boeing reconnaisse que les vraies Directeurs de Projets (industriels) 'maison', ayant un talent pour les "trouble-shooting & crisis management" / 'gestion de crise',...se trouvaient dans la Division 'Défense' ! D'où le transfert de P. SHANAHAN. Et lui a fait venir 15 de ses co-équipiers de la Division 'Défense'! Mais, manque de chance, P. SHANAHAN & ses collègues ont eu à se battre avec les "design -flaws" !

sevrien a écrit:En sus, il y a , maintenant, les problèmes de la conjoncture économique, doublés par les difficultés dans les relations sociales, et le mécontentement des "machinistes", devant la proportion élevée d'externalistion, qui, à leurs yeux, leur enlève du travail !

sevrien a écrit:Un ingénieur de RR m'a dit : "Certes, la course vers les nouvelles technologies n'a pa facilité les choses ! Mais, ...à la limite, ce n'est même pas le problème des composites ! Boeing aurait les mêmes problèmes, dans sa structure actuelle,, pour ce programme B787, même s'il s'agissait d'un avion en métal ! Chaque projet de ce genre a besoin d'une base, ... d'un point ferme, dur, et pivotal ! Ce projet a une forme de "amoeba", soit......'pas de forme'.. du tout, puisque cet organisme change de forme tout le temps, et, par définition, n'a pas de point ferme, dur, et pivotal !

Prediction: First delivery of Boeing 787 will push until 2011
Last week, Boeing said that it would push back first flight of the 787 for an unknown amount of time, which shed doubts on whether Boeing would be able deliver the 787 in the second quarter of 2010 as promised.


At least one analyst says that the first customers may have to wait yet another year for Boeing's all new 787 Dreamliner, which is already two years late.

First delivery of the 787 could be as late as 2011, Morgan Stanley analyst Heidi Wood said in her most recent research note to investors.

She predicts that the "earliest feasible time" that first flight could occur would be the last quarter of 2009. Then, more time will be needed to get the plane tested and certified.

Boeing had to push back first flight because of unforeseen stresses on the aircraft where the wing joins to the body.

What is particularly worrisome, Wood says, is that Boeing's computer models did not predict the stress. But in order to get its new plane legally certified, Boeing must prove to the Federal Aviation Administration that its predictive modeling works, Wood said.

"Based on the program's track-record for continual negative discovery, we don't see the wisdom in assuming (last week's) revelation represents the very last setback," Wood said. "In fact, what worries us is the potential for more negative insights through the certification phase. Failure of the predictive models to anticipate the stress points that suspended first flight presents real risk the FAA will now insist on more data, slowing certification, hence our assumption for 2011 first delivery."

Months may transpire before Boeing is able to do what it failed to accomplish in the last week of June - fly the 787 for the first time - following the revelation that the new airplane's composite wing induced delamination and deformation on body join points during a routine preflight stress test.

The company says it will take at least several weeks of data analysis before it will know how long it must delay first flight, which had been expected to take place by June 30. Also of concern is how close it can come to meeting its promise to launch customer All Nippon Airways to deliver its first aircraft in the first quarter of 2010.

Disclosure of the side-of-body stress failure on a June 23 conference call came as flight-test aircraft ZA001 was completing its final gauntlet systems tests and preparing for taxi tests that would set it up for first flight. Despite the test failure, those preparations will proceed, says Boeing Vice President Pat Shanahan, general manager of airplane programs. He predicts that once a design to strengthen the wing-body join area is tested and verified, installation can be accomplished on the flight line, avoiding a time-consuming return to the factory floor.

But it is not clear how much of Boeing's beleaguered schedule for the standard sized 787-8 will be eaten up by the delay. A senior analyst and engineer with knowledge of Boeing's programs points out that recovery from what appears to be very bad design failures sometimes happens in a matter of weeks. However, that has not been Boeing's experience on the 787. This is the sixth time first flight has been pushed back. Many of the previous announcements were adjustments to additional bad news that negated earlier optimistic estimates (see timeline below).

Boeing Commercial Airplanes President and CEO Scott Carson says, "We will correct the situation with both care and urgency."

Since Boeing first began announcing delays in September 2007, Wall Street has been growing increasingly skeptical of the company's predictive powers. Citing the program's "track record for continual negative discovery," Morgan Stanley analyst Heidi Wood expects a first-flight delay of 3-6 months, putting it as far back as the fourth quarter of 2009, assuming there are no further problems. First delivery is estimated for 2011.

The concern over the unexpected wing stress failure centers not on the test results themselves, but on the fact that Boeing's computer-aided design did not predict them. The design software is not suspect; the data and models that were fed into it are.

Discrepancies between designs and actual tests are nothing new. Nor is this the first problem the 787 program has had with software development. Software at the systems level is one reason the program has run late.

But those issues have been resolved. The trouble here is that the design discrepancy appeared so late in the preflight program. "If they had had the right configuration data/models in the system, they would have found [the problem] earlier" and been able to correct it, the analyst and engineer says.

Boeing Vice President and 787 General Manager Scott Fancher agrees. "If we had found it a couple of months ago, we wouldn't be having this phone call," he commented. Instead, Boeing and its supply team would have identified a stiffener fix, installed it and the flight-test program would have been unaffected.

Even before this latest incident, Boeing struggled to manage its worldwide supplier network. When the program first fell behind, the original management team was replaced and Shanahan moved quickly to tighten management oversight of the 787 supply chain and reorganize the program's management.

Initially, program execution was the stumbling block. The supply chain was breaking down. While still not perfect, supplier feeds to Boeing are proceeding more smoothly now.

This time, program development is to blame. Management of the aircraft's detailed design data, which has flowed across the Internet to Boeing from manufacturing partners scattered around the world, is proving faulty.

Boeing has already moved to corral the problem. As it works on final configuration for the next member of the family, the 290-seat stretch 787-9, it is pulling back design authority from contractors to its own engineering team and "double- and triple-checking" any specific design work they have done, says the analyst.

Shanahan reported that analysis of stress data from a wing bend exercise showed a disconnect between the test's actual results and the prediction of the computer design. The test was on the ZY997static test airframe. In fact, more than a numerical discrepancy showed up. Deflection and delamination occurred inside the fuselage when a titanium fastener didn't transfer the load of that bend properly, the analyst explains.

Shanahan says a first reading of strain gauge results revealed a problem, but not one the 787 team thought jeopardized first flight. As a result, he and other Boeing officials remained bullish at the Paris air show that they would make their June 30 deadline.

"Our models are predictive and have demonstrated to be very accurate," he says. "To date, we have exceeded expectations in our ability to predict the structural performance." Apparently, that is why, when further analysis revealed a disconnect between the computer-predicted performance and actual test results, Boeing knew it needed to suspend flight-testing to avoid certification issues later.

"Our work is largely focused on understanding the issue," says Fancher, who was brought in as 787 general manager when Shanahan was put in charge of all airplane programs.

Several potential modifications are possible to strengthen the join of Mitsubishi Heavy Industries' composite wing box, which stretches across the fuselage's Sec. 11 composite center wing box made by Fuji Heavy Industries and the Sec. 45 composite main landing gear wheel well from Kawasaki Heavy Industries. The wing join to these body sections is presumably accomplished with titanium fasteners because titanium does not have corrosion issues with composites as aluminum does.

Fancher says Fuji, Mitsubishi and Boeing will design an interim fix - presumably stiffeners - and then move on to the longer-term solution for production aircraft. That may involve reworking composite molds.

The parts needed are small, only a square inch or two, Fancher says. He expects 18 to be applied to the top side join of each wing.

In June 2008, Boeing successfully tested a two-thirds scale wing box by bending it far beyond a normal flight profile. It passed the test. But it was anchored to a concrete wall, not an airframe.

The ZY997 static airframe tests are more critical because they are full size and full fidelity to verify the safety of the airplane.

Besides assuring the integrity of the wing under normal flight loads, Boeing is required to subject it to 150% of normal loads in an "ultimate load test." However, at this stage, the static rig is still working on basic pull-up stress-testing.

This is not the first wing problem the airplane has suffered. Boeing and Fuji had to counteract structural weaknesses in the center wing box that were uncovered during an earlier validation and certification test. The solution included installation of interim stiffeners for the six flight-test airplanes. The seventh, which will be delivered to ANA, was built with a redesigned unit (AW&ST Mar. 24, 2008, p. 36).

In fact, wing test failures have long been an issue in new aircraft programs, especially when boundaries are being pushed. Airbus had to bulk up the massive wing of its A380 when it failed at 145% of the ultimate load, a fact that contributed to it falling two years behind schedule. Further delays in the 787 will probably give Boeing the distinction of surpassing that dubious mark.

In the 787, Boeing is pushing a lot of boundaries - in the innovations it is taking with an integrated supplier network, the application of composite technology to a large airframe and introduction of a new electric architecture for aircraft systems.

"It's a very sad story," says Danny Eylon, chairman of the graduate materials program at the University of Dayton. "But Boeing took a fairly big gamble. In fact, they gambled twice. Once was when they used an all-composite aircraft, starting at the top with a widebody. Typically, you would take on a regional first and then go onto a single-aisle and then to a widebody. Then they went to a barrel design, which also is a very challenging structure." His reference is to composite barrel sections laid up in one piece.

Nonetheless, Eylon is impressed with the design Boeing set for the 787. "In the end, they will have a very efficient structure," he says.

Boeing has not revealed the 787's development cost. Previous delays pushed it to $15-20 billion for all partners, according to some analysts' estimates. Carson says it is too early to say how much this latest delay will add to that figure.

Suppliers report that they have not been asked to change their production and delivery plans because of the latest slowdown. "As far as the immediate impact of any production, it's too early to tell," said a spokeswoman for aft fuselage maker Vought Aircraft. Shipsets for the second deliverable airplane are now in process. Boeing has not said when they are due at the factory in Everett, Wash.

"It's a development program for us," says an official at Hamilton Sundstrand, the 787's biggest systems supplier, meaning that ups and downs are part of the process.

Still, Boeing has had to compensate its suppliers and customers for program delays.

The company has lost about 6% of its order book, although its more than 850 orders are still a record. Within its walls, Boeing is said to be "white with panic" at the prospect that its commanding order lead in commercial aviation's hottest new market could be in jeopardy.

So far, the customers lost seem to be responding to financial constraints not directly tied to the 787. But Virgin Atlantic, which ordered 15 787-9s in April 2007, says it is considering the rival Airbus A350XWB and recently bought A330-300s. Akbar al Baker, chief executive of Qatar Airways, which has ordered 30 787-8s and but also 20 A350-1000s, complains that Boeing is being run by "bean counters and lawyers" who do not pay proper attention to customers.

ANA's order for 50 airplanes was the largest the Japanese carrier had ever placed and its first program launch. Its frustration at continued delays is increasingly apparent. The latest one prompted ANA to urge Boeing "to specify the schedule for the program as a whole as quickly as possible."

The process Boeing faces now is to verify its analysis and the parts necessary to stiffen the fuselage-wing join. Then it must install the fixes in ZY997, put its wing through a new set of bending tests and verify the results of those tests relative to the computer design. Only then can it begin installing the parts into the flight-test and production aircraft and begin modifying the molds for subsequent wings and wing boxes.

With almost a month since Boeing announced it was forced to ground its 787s for structural reinforcement, the company continues to work to develop, install and test a fix that can get its troubled Dreamliner into the sky after more than two years of delays.

According to a senior program source: "There is good news and bad news. The good news is we know what to fix, and how to fix it. The bad news is the location is a [expletive] to get to."

Boeing says that revised schedules for first flight and delivery remain under review, as they have been since the company's June 23rd news conference.

DIAGNOSIS & DEVELOPMENT

While the fix is being developed and a fully revised schedule finalized for airlines, sources at both Boeing and partner suppliers indicate that the existing production plan has slid roughly one and a half to three months for the delivery of Airplane Ten's components to Everett, even as suppliers continue to prep parts for shipment.

The slip, the sources say, allows Boeing to finalize and test the fix and limit the number of aircraft in final assembly required to undergo the fix in Everett. Boeing previously stated that any fix developed would be able to be installed no matter the location of the parts in the supply chain.

Airplane Eight, ZA101, is expected to begin final assembly operations before the month is out, with parts for Airplane Nine, ZA102, believed to be arriving beginning in early August. The slip, one supplier sources say, could mean that structural components for Airplane Ten, ZA104, may not arrive until October. The customer ZA-designations are non-sequential.

The side-of-body issue was first discovered in late-May during a test that saw lower wing loads than the April 21st test of 120-130% of limit load. The test revealed the weakness in the upper section on the stringer caps of the wing to body join at the side of body of the aircraft.

A corps of Boeing engineers are working 80-hour weeks to design the fix that allows the 787 to fly with a robust flight envelope and achieve FAA certification with 150% of limit load on the wing, sources say.

For the development of the remedial fix, widely believed to be made of titanium, engineers have to design a modification that avoids two potential challenges down the road.

Veteran structural engineers tell FlightBlogger that the key to developing a reinforcement centers around ensuring that the loads that caused the initial problem at the site of the wing stringer caps are not redistributed elsewhere causing a further structural issue.

Second, as the area is stiffened Boeing engineers must take great care to develop a fix that isn't susceptible to long term fatigue issues that come from the normal structural aging of the aircraft.

These challenges aren't unique to structural engineering on the 787, in fact, they are part of the normal checklist that comes with developing the solution that is the 3-dimensional puzzle of designing aircraft. This is not to say, however, that solving the problem is any less complex, difficult or time consuming.

INSTALLATION

Several program sources indicate that August is a crucial month for the wing fix as the development phase moves into the installation phase.

Boeing reiterated that its engineers are "working with urgency", and no internal timeline has been finalized for the testing or duration of the installation of the fix.

Sources say the area that will be reinforced at the side of body is extremely tight and difficult to reach as the installation area of the fix will provide very little room to install the fasteners to secure the reinforcement.

The installation of the fix may begin as early as the middle of August, with installation times around one month for each already assembled airplane, sources estimate.

Boeing has nine 787s at its Everett facility (6 flight test, 1 production, 2 ground test) that have gone through, or continue to undergo, final assembly operations, and structural sections for a 10th (Airplane continue to arrive.

ZA001 is expected to leave the flight line for Paint Hangar 45-03 where the first 787 will undergo installation of the fix.

ZA002 will remain on the Everett flight line and the area around the side of body will be covered with a specially ordered tent to protect the aircraft.

In addition, Boeing has moved the approximately 50-foot long, two-thirds span test wing box, known as the "Dash 18" wing, from the company's Seattle Development Center to Building 40-23 where 787 static testing has been taking place in Everett.

The company is considering using the test wing box, which was formally broken in November 2008 above 150% of limit load, to test installation methods as a dress rehearsal before modifying the static test airframe and ZA001.

PERMANENCE & PRODUCTION

Even with the remedial fix in the works, a key discussion centers on the future of 787 production and when the permanent fix is designed into the wing to body join.

Sources say a revision of the upper part of the wing to body join is almost certainly necessary to create a permanent long-term solution and eliminate the time consuming installation of the remedial fix.

Boeing says there are about 40 787s in process throughout the global supply chain and a question yet to be answered is the timing of incorporation for the permanent fix.

Boeing has already planned a series of blockpoint changes to incorporate weight reduction and performance improvements into the design of the aircraft. The first major blockpoint was for ZA100, the first production 787 (Airplane 7), with the next expected to follow around Airplane 20.

Airbus faced a similar challenge when the A380 wing ruptured below the 150% mark in 2006 forcing the European airframer to modify aircraft already in final assembly. Airbus eventually incorporated its own remedial fix into A380 production before the wings were delivered to Toulouse, however the company has had to redesign the effected area as a long-term solution.

In different circumstances, the strong second quarter earnings results issued by Boeing this morning would be received enthusiastically by investors.

In the midst of the worst financial crisis since the Great Depression, second quarter net income was up 17% from the same period a year earlier and the company eked out a 1% sales gain. But while those results bested Wall Street's consensus estimate, most investors are fixated on something that Boeing couldn't deliver - an update on how long the first flight of its troubled 787 jet will be delayed and how much of an impact that will have on future earnings. "Second quarter earnings per share beat our estimate and consensus, but with the absence of a new 787 schedule, we see this largely as a non-event," said JPMorgan analyst Joseph B. Nadol.

Boeing delayed a scheduled first flight of the 787 last month after a static test failure in the aircraft's wing-body join area that had not been anticipated in computer modeling, embarrassing company executives, who had maintained that the program was back on track after five previous delays. Faced with question after question about the delay in an earnings call with analysts and journalists on Wednesday morning, Chairman and CEO James McNerney sought to downplay rumors that the fix would be costly and time consuming and could involve a redesign of the 787's wing. "We have learned nothing that says anything other than this is a local issue with a local fix," he said. "&.We do not see a systemic issue with the entire wing."

But four weeks after the latest delay was disclosed, McNerney could provide no details about how long the problem will set back the 787 flight test and delivery schedule. "The team is making solid progress toward resolving this issue&we'll be in a position [later] this quarter to talk about those impacts," he said.

McNerney also faced several questions about how the static test failure could have taken Boeing managers by surprise at the 11th hour. "Bad news doesn't appear to flow up," said Bank of America/Merrill Lynch analyst Ron Epstein.

"This is not an issue of information flow," McNerney responded. "It's an issue of the thousands upon thousands of tests we do....One of them turned up wrong that we didn't anticipate."

Among other highlights in the company's second quarter earnings:

*McNerney said there is "no change" in Boeing's position that it can maintain 737 narrowbody build rates at 31 per month.

*The company had 57 orders for commercial aircraft during the quarter but lost 52 previous orders, for a net of five. In addition, there were 70 delivery deferrals in the second quarter, adding to 60 in the first quarter. But the company says its backlog of deferral requests is declining.

*Revenues at the Integrated Defense Systems unit were up 3% from a year earlier and margins came in at 10.1%.

*Company-wide, backlog declined 3% to $328 billion as deliveries outpaced net orders, but still stands at nearly five-years worth of sales.

*Boeing has significantly reduced aircraft inventories since last year's machinists strike, but 787 inventories will continue to build until first deliveries begin.

Boeing also disclosed that it has eliminated 5,000 positions since last November and is on plan to raise that to 10,000 by the end of the year.

Boeing remains profitable, closes in on 787 fix
Thursday July 23, 2009

Boeing reported a $998 million profit in the second quarter, up 17% from the $852 million earned in the year-ago period, and said it has identified a fix to the defect in the 787's upper wing join area that led to last month's first flight postponement and will release a new schedule for the flight test program before the end of September.

"I can tell you the team is making solid progress toward resolving the issue. . .From an engineering standpoint, the fix design is straightforward and requires a relatively small amount of parts to be applied to the area that needs reinforcing. . .it's a local issue that can be addressed with a local fix," Boeing Chairman, President and CEO Jim McNerney told analysts and reporters yesterday.

Higher stress levels than expected during static testing prompted the manufacturer to postpone indefinitely the first flight scheduled for late June (ATWOnline, June 24). McNerney said yesterday that engineers now are working on an implementation plan that will not create "collateral issues." He said, "We have a high degree of confidence but we're working with an abundance of caution."

The fix is not expected to have an impact on either performance or maintenance. "There isn't that much weight involved and the performance of the plane is not impacted, therefore it's a matter of working through this issue and getting to the other side and getting the program back on track," he said, adding that postponing first flight again "was the right decision." He promised a "full plan" before the end of the third quarter. The program has suffered 73 cancellations this year.

The company's second-quarter revenue rose 1% to $17.15 billion "driven by growth in defense programs and strong performance in defense and commercial airplanes," it said, with operating profit up 23% to $1.53 billion.

Boeing Commercial Airlines reported a 2% fall in revenue to $8.43 billion and a 5% increase in operating profit to $817 million. It delivered 125 aircraft during the quarter, down one from last year. It booked 57 gross orders (including 13 787s) and had 52 cancellations. Its six-month operating profit was down 30% year-over-year to $1.23 billion. BCA expects to deliver 480-485 aircraft this year, with revenue targeted at $34-$35 billion.

The hope is that will reduce the stress point load enough to prevent future delamination.

Boeing 787 may not fly this year
The structural flaw that delayed the first flight of the 787 Dreamliner is more complex than originally described by the company, and the plane's inaugural takeoff is likely at least four to six months away, say two engineers with knowledge of Boeing's problem.

By Dominic Gates



Heading into today's quarterly earnings report, Boeing has neither set a new schedule nor outlined its plan to fix the structural flaw discovered in May.
The structural flaw that delayed the first flight of the 787 Dreamliner is more complex than originally described by the company, and the plane's inaugural takeoff is likely at least four to six months away, say two engineers with knowledge of Boeing's problem.

"It's got to take at least three to four months just to get something installed on an airplane," said a structures engineer who has been briefed on the issue. "It's definitely a costly fix to go and do this work."

A second engineer, who is familiar with the details of Boeing's construction method, said the fix must first be made on the nonflying test airplane in the Everett factory. Assuming that's successful, it will take another month or two to install the fix on the first airplane to fly.

Both engineers said the issue requires a thorough redesign of the plane's wing-to-body join, and the necessary parts will be very difficult to install on the test airplanes that have already been built.

The engineers' accounts differ from Boeing's description June 23 when it acknowledged a problem and again postponed the first flight of the much-delayed plane.

Dreamliner program chief Scott Fancher said then that the fix would be "a simple modification" requiring only "a handful of parts." But almost a month later, heading into today's quarterly earnings report, Boeing has neither set a new schedule nor outlined its planned fix of the problem.

The second engineer said the problem is caused by high loads at the ends of the stringers on the upper wing skins. Stringers are the long composite rods, shaped like I-beams, that stiffen the inside of the wing skin.

There are 17 stringers on each upper wing, all of them subject to compression forces when the wings flex upward in flight. At the point where each stringer ends, close to where the wing and body of the plane are joined, those forces pull the stringer away from the skin.

During a wing-bending test in May on the ground-test airplane inside the Everett factory, the fibrous layers of the composite plastic material delaminated at these stress points.

Such a separation of the material isn't likely to lead to catastrophic failure of the airplane, but it would require constant monitoring and potentially costly repairs by the airlines. Any tear in the material would have to be promptly fixed to avoid spreading of the delamination.

If Boeing's initial fix fails to divert enough of the load away from the stress points, the delay in first flight could extend beyond six months, pushing the date out into 2010.

"There's no guarantee that what (Boeing) is doing will work," the second engineer said. "If the testing or analysis shows it doesn't get rid of the load, then the engineers are back to square one."


Further delays

Beyond first flight, solving the structural flaw could also further slow the plan for ramping up production.

Boeing's current focus is on an interim solution to the stringer problem for the test planes that it has already built. The first engineer said Boeing hasn't had time yet to figure out at what point in production to introduce a permanent redesign on all subsequent jets.

"None of that is nailed down yet," he said. "There's no schedule."

Boeing has a large team of engineers working on the analysis, the redesign and how the fix could be implemented.

Those engineers are focusing on a solution that will send mechanics inside the wings of the assembled planes to trim the ends of each upper wing-skin stringer. They will create a U-shaped cutout in the end of the stringer, leaving the flanges at top and bottom untouched.

The U-shaped cut in the stringer ensures that the load on the flange away from the skin, the inner flange, will transfer entirely into the strong titanium fitting at the wing-body join and not into the wing skin, the engineers said.

The hope is that will reduce the stress point load enough to prevent future delamination.

The reshaped stringer ends must be refastened with newly designed parts to the titanium fitting, which connects the wing stringers to similar stringers on the fuselage side of the join.

And the design must accomplish this without creating another stress point somewhere else.

To reinforce the stringer ends, mechanics will also add some fasteners that go through stringer and skin. The 17 stringers on each side don't all require the same reinforcement, but Boeing wants one design fix for all, so whatever is the beefiest reinforcement needed will likely be done for all the stringers, said the first engineer.

This retrofit will be tremendously difficult to implement on the airplanes already built because the mechanics will have to do the tedious and meticulous work inside the confined space of the wing.

"Drilling holes in titanium is difficult. Drilling holes in composite is difficult. And the access will be very difficult," said the second engineer.

And when Boeing finally comes to do the job on Dreamliner No. 1, it will first have to empty the fuel from the wing tanks so that repair crews can work inside.

Previous problems

Excessive loads at stringer ends (known to engineers as "runouts") is not something that should have struck Boeing out of the blue.

"The problem with stringer runouts has been identified in the past and recognized as a problem," the second engineer said. He said the issue has arisen on other composite airplanes.

Indeed, the first engineer said the stress point at the end of the 787 stringers showed up as a "hot spot" in Boeing's computer models before the delamination in the wing bend test — but for some reason it was never addressed.

The delamination happened after the wing bend test reached ultimate load, which is 50 percent higher than the maximum load expected in service.

The second engineer said reaching that load proves that Boeing's heavy titanium structure is as strong as it needs to be. However, the delamination of the wing skin could have begun well before that load was reached, he said.

In the tests of the proposed fix that lie ahead, he said, engineers will have to inspect the stress points for delamination closely at every increment up to the highest loads.

Boeing spokeswoman Yvonne Leach said the company "will provide details on the technical solution in due course as we finalize our plans for implementation."

The company reports its quarterly earnings before the stock market opens today.

In an early-morning teleconference after the earnings news is released, Boeing management will be quizzed closely by Wall Street analysts for more detail on the expected program delay. It's likely the executives won't yet have precise answers.

787's structural design problem, centered on the upper wing join area, is more complex than originally outlined by Boeing and may result in first flight being delayed until next year, engineers told The Seattle Times. One engineer with knowledge of the problem claimed that it will take "at least 3-4 months just to get something installed on the 787," while a second, familiar with Boeing's construction methods, claimed that the fix first must be installed on the nonflying test aircraft in Everett and only will be applied to flight test aircraft if proven successful. It has become apparent that it will be difficult to apply the fix to aircraft already completed.

However, Chairman, President and CEO Jim McNerney claimed during Wednesday's second-quarter results announcement that the manufacturer is "making solid progress" toward resolving the issue and plans to issue a revised program timetable by October (ATWOnline, July 23). It has completed gauntlet testing on the first 787 and conducted taxi testing up to 130 kt., while the second Dreamliner has run up its engines. The third and fourth aircraft have been powered on and off. But the latest structural problem likely will have a serious impact on deliveries, according to a client note issued by Bernstein Research of New York. It suggested that the company now will deliver only three in 2010, down from 15; 25 in 2011, down from 35, and 50 in 2012, down from 60.