BOEING DREAMLINER

Made From Composites

by Alex Hutchins

The Boeing 787 Dreamliner is a long-range, mid-size wide-body, twin-engine jet airliner developed by Boeing Commercial Airplanes. It seats 210 to 290 passengers, depending on the variant. Boeing states that it is the company's most fuel-efficient airliner and the world's first major airliner to use composite materials for most of its construction. According to Boeing, the 787 consumes 20% less fuel than the similarly-sized 767. Its distinguishing features include a four-panel windshield, noise-reducing chevrons on its engine nacelles, and a smoother nose contour. The 787 shares a common type rating with the larger 777 twinjet, allowing qualified pilots to operate both models, due to related design features.

However, Boeing’s Dreamliner has some serious issues.  According to a recent article in The Seattle Times, “Boeing and General Electric pulled an engine off a new 787 Dreamliner jet for testing as U.S. officials decided to open an investigation into why the unit spewed debris over the weekend.”

 

The National Transportation Safety Board (NTSB) will send an engine specialist and a metallurgist to a GE facility in Cincinnati to coordinate the examination, the agency said Tuesday in a statement. The NTSB said it acted after an investigator visited the scene in Charleston, S.C.

Debris blew out of the engine during a July 28 high-speed taxi test of an Air India 787 at the Charleston airport near Boeing's new factory there, igniting a brush fire along the runway and temporarily diverting and delaying flights. The safety board didn't release any new information about the damage to the engine or what might have caused it to fail.

The Next Generation Turbofan

The GEnx is GE's next generation turbofan and will be the workhorse engine of the 21st century for medium-capacity, long-range aircraft.

Engine Overview

Designed around customers' needs, the GEnx represents a giant leap forward in propulsion technology. The engine will use the latest generation materials and design processes to reduce weight, improve performance and lower maintenance.

The GEnx is part of GE's "ecomagination" product portfolio - GE's business strategy to develop new, cost-effective technologies that enhance customers' environmental and operating performance.

The GEnx will deliver 15 percent better specific fuel consumption (which translates to 15 percent less CO2) than the engines it replaces, helping operators save whenever they fly. Its innovative twin-annular pre-swirl (TAPS) combustor will dramatically reduce NOx gases as much as 56 percent below today's regulatory limits. Additionally, the GEnx's emissions for other regulated gases will be as much as 94.5 percent below current regulatory limits, ensuring clean compliance for years to come.

The low-pressure turbine drives the engine’s fan and is the tail end of the process, Weber said.  Hans Weber is Chief Executive of the San Diego-based aviation consultant group, Tecop International, Inc.  There’s an “incredible amount of heat” in that area because it comes after the combustion chamber, he said. The blades “are marvels of engineering and metallurgy” that rely on fine air passages and heat-resistant coatings to resist temperatures higher than the melting point of the nickel alloys used, he said.

Every part is carefully inspected and tested at the engine factories before being installed, said Weber, a physicist who has worked in the aviation industry for about 30 years and helped develop better part-testing techniques in the 1990s.

“I can’t imagine how some defect could have slipped through,” he said. “Hopefully this will continue to be an extremely rare event and one that we won’t see again in a very long time.”

Mr. Hans Weber cannot imagine this, but I can, after having worked in manufacturing for several years!  If we are 99.7% accurate according to engineered specification, that production process still produces 2600 out of spec part per million; but if we are 99.9999997%, then only 1-3 out of spec parts per million are produced.  This concept was developed by Motorola and referred to as Six Sigma. 

When Jack Welch and Larry Bossidy were at General Electric, the company was a Six Sigma supplier.

BTW, the GE plant that made the GEnx engine is located in Cincinnati, OH home to Skyline Chili and considered, by many, to be the best chili in the US – wonder if this had anything to do with it???