BOEING 787 DREAM LINER MATERIALS....
Aerospace giant Boeing Co. calls its new 787 aircraft the Dreamliner, but in the closing weeks of 2007 the project has become something more closely resembling a nightmare. After promising to deliver its game-changing aircraft -- "the fastest-selling plane in commercial aircraft history," according to Morgan Stanley analyst Heidi Wood -- in May 2008, Boeing ultimately took a deep gulp and admitted the project's timeline was far too ambitious; the latest schedule now hopefully targets late November/early December 2008, a delay of at least six months.
What happened to derail the momentum of one of the most significant marriages of manufacturing and supply chain management in history? Explaining the delay, Scott Carson, Boeing's executive vice president of commercial airplanes, put it succinctly: "It has simply proved to be more difficult than we anticipated to complete the structural work on the airplane out of sequence in our Everett [Wash.] factory."
Despite the delay, Boeing's 787 Dreamliner still has the potential of inspiring and redirecting product strategies in other manufacturing sectors. Commercially, the aircraft is already a hit. As of mid-October, 50 airlines already had ordered 710 Dreamliners worth an estimated $100 billion. (Want to order a 787? Expect delivery in 2015.) And while the project is taking more time -- and a lot more work -- than originally anticipated, Boeing "remains confident in the design of the 787, and in the fundamental innovation and technologies that underpin it," stated Jim McNerney, president and CEO, when he announced the delay.
Shown are the horizontal stabilizers attached to the tailcone of the Boeing 787 Dreamliner, with the vertical fin in the background. |
On the technology side, Boeing first had to devise a combination of materials to lighten the airframe: 50% composites by weight (80% by volume), 20% aluminum, 15% titanium, 10% steel and 5% other. Competitor Airbus has started playing the same game, but while Airbus is readying a similar lineup of materials for its 350-800, that plane is not due until 2014.
The payoff of that material mix is a 20% reduction in fuel consumption compared with conventional aircraft of similar size. In addition to the lightweight composites, three other key technologies contribute to that performance: new, more efficient engines, more efficient systems applications and aerodynamic updates of the wing surfaces.
Using composites also offers an environmental edge in terms of scrap and waste reduction, says Mike Bair, formerly the head of the 787 program and now vice president of business strategy and marketing for commercial airplanes. (The delay announcement led to a corporate reshuffling that replaced Bair with Pat Shanahan.) Building with composites avoids the metal-shaping debris from the milling or machining of aluminum parts. Bair says shaping an aluminum blank by milling or machine can mean losing as much as 90% of its volume to reach the required configuration.
A Little Help from Their Friends
The composites strategy Boeing is developing for the 787 will greatly reduce the need for airframe maintenance, predicts Mike Bair, vice president of business strategy and marketing for commercial airplanes. |
With the 787 program, Boeing is now globally outsourcing approximately 70% of content, compared to 50% previously. For example the forward fuselage comes from Kansas, the center fuselage from Italy, the aft fuselage from South Carolina, and wings from Japan fitted with Australian trailing edges and leading edges from Oklahoma. Bair says Boeing's rationale for increasing its outsourcing strategy is recognition that the best process skills increasingly lie outside Boeing factories. Tokyo-based Toray Industries supplies the carbon fiber.
To facilitate parts delivery, in January 2007 Boeing rolled out its first Dreamlifter, a specially configured 747-400. The first load -- large composite parts -- was picked up from Kawasaki Heavy Industries, Nagoya, Japan, for delivery to Charleston, S.C.
Son of Sonic Cruiser
The 787 concept didn't begin as a super fuel-efficient Dreamliner to be made largely of plastic composites. Bair traces the origins of the 787 to the mid 1990s, "when we knew we had to put together a replacement for the Boeing 767. The 767 was an airplane that was getting bruised in the marketplace by the Airbus A330-200."
Boeing's ongoing market analysis provided the direction for the 787. "We knew that we would have to come up with an airplane of 200 to 250 seats with long-range potential," Bair says. Fuel efficiency was not the original goal, he admits. "Our initial thinking was to take the composite structure and configure all the systems and improvements and produce a design with the same operating economics as the 767, but it would fly at almost the speed of sound -- a 20% improvement in speed. We called it the Sonic Cruiser."
Bair says the airlines initially wanted a premium product to match the upbeat financial optimism of the pre-9/11 period. He sums up the travel philosophy of the time as: "The only reason any of us suffer airplane flights is to get someplace quickly."
"A piece of aviation history." That's how Boeing greeted the arrival of the first composite fuselage structure for the 787. The composite structure achieved more than part reduction. Boeing says it reduced weight by almost 20% and added structural integrity. The composite structure enables bigger windows, lower cabin pressurization and higher cabin humidity. |
The evaluation procedure then directed the airline team to schedule the operating characteristics of both planes into their route networks to see how operations would be affected, says Bair. "The next step was to vote for the preferred concept and they unanimously selected more efficient operating economics, not speed."
Why not speed? "In practice, on many routes, speed didn't provide a usable advantage," Bair relates. "For example, in an evening flight from Singapore to London, a 20% speed increase would mean inconveniently arriving in the wee hours of the morning. That's worthless." Bair says that vote launched the 7E7, the initial concept name of the 787.
A Sweeter Ride
The performance benefits of the composite extend beyond weight efficiency. For example, Bair says the composite construction is responsible for the 6% increase in the plane's aerodynamics performance compared with the 777. "The composites enable us to produce wing surfaces that are too long and too thin to be built out of aluminum."
Bair says the composites used in the fuselage offer maintenance advantages in addition to weight savings. By not being susceptible to fatigue and corrosion, composites will enable airlines to stretch the intervals between "heavy checks" to double the six-year interval specified for aluminum. That maintenance procedure requires the removal of a plane's interior to check for structural problems such as fatigue or corrosion. Bair predicts that "heavy checks" of the 787 will show that composites greatly reduced the need for airframe maintenance.
Composites also provide benefits that more directly connect to passenger comfort. Since composites do not have aluminum's sensitivity to fatigue damage, cabin pressure can be increased to add passenger comfort. "In aluminum planes, pressurization during flight is roughly equivalent to an altitude of 8,000 ft. Achieving the pressurization of lower altitudes is not practical with aluminum because of the added weight of the necessary structural reinforcement," Bair explains. He says passengers will feel more comfortable in the 787 because the composites enable cabin pressure to be maintained at a 6,000-ft. altitude level. Boeing tests show passenger discomfort occurs at pressures common to higher altitude levels.
Passenger comfort is also increased by the composite's ability to tolerate higher cabin humidity levels. Bair says humidity levels in composite cabins will be maintained at 10% to 15% versus the 5% or less common to conventional aluminum bodied planes.
Material World
Boeing's accumulated experience with composites dates back to the early 1980s. "We first tested composite horizontal tails on five 737s, and that led to using composites for the horizontal and vertical tail assemblies and floor beams for the 777." Bair says switching to composite floor beams eliminated that part's replacement frequency and helped build the market volume that is reducing prices for the 787 applications.
"Those material cost reductions are a major strategic victory that has helped make 787 prices appealing to airlines. The other breakthrough on the 787 centers on production cost. We knew technically how to build an all-composite airplane, but the real breakthrough on the 787 was to be able to build one at a price that the airlines could afford."
Bair says that cost success derives from Boeing building composite aero structures with current raw material usage approaching 10 million pounds annually. (That figure refers to applications in the 777.) Moving to composites also changes the look and feel of an aerospace manufacturing facility, "from that of a machine shop to something looking more like a textile mill." He cites the growing presence of clean rooms and a high degree of automation, with much of the staff outfitted in white lab coats.
Despite the delays, Bair is enthusiastic about the chances for continued dramatic improvement with composites. "With aluminum we were running out of ideas on how to do it better. From the start the economics with composites were slightly better than with aluminum, and every day we're learning more and more to make it better. We have a lot of runway ahead of us to constantly improve this process."
Boeing is also simplifying the systems architecture of the 787. Examples include replacing the complex high-pressure bleed air systems with electric motor-driven compressors for pressurization and air conditioning. Another example could be labeled "fly by Ethernet," where the mature Ethernet standard becomes the 787's fly-by-wire communications backbone. Bair says Ethernet is simpler and much less expensive to utilize than the more limited standard originated by the aircraft industry.
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