NewsDesk: Testing Advances on 787 Battery Fix
The Boeing Co. (Chicago, IL) continues to move quickly to solve issues surrounding the lithium-ion batteries installed in its 787 Dreamliner, which has been grounded since mid-January, and the model could be back in the air by June.
On Jan. 16, the FAA issued an emergency directive that grounded all Boeing 787s in the US following two incidents, including one fire, involving lithium-ion batteries. It was the first time the FAA had issued a general grounding of an aircraft model since 1979. Several other countries, including Japan and India, followed suit.
An in-depth probe into the cause of the overheating was launched by Boeing as well as US and Japanese transportation safety officials.
On March 12, Boeing received approval from the FAA on its plan to test and certify improvements to the 787’s battery system.
Details on 787 Battery Improvements
Boeing said it has developed a set of improvements to the 787 lithium-ion batteries that add several layers of safety and reliability to the design. These improvements are undergoing extensive certification testing. Once testing is complete and the FAA and other international regulators grant their final approval, operators will be able to safely resume commercial flights of their 787s.
Improvements include enhanced production and operating processes, improved battery design features and a new sealed battery enclosure.
Battery system enhancements address possible causes of battery failure identified by the Boeing technical team. The technical team’s findings were verified by an independent group of lithium-ion battery experts from industry, universities and national laboratories.
Boeing teamed with Thales, the provider of the integrated power conversion system, and battery maker GS Yuasa to develop and institute enhanced production standards and tests to further reduce any variation in the production of the individual cells as well as the overall battery.
Four new or revised tests have been added to screen cell production, which now includes 10 distinct tests. The batteries have eight cells, each of which will now go through more rigorous testing in the month following its manufacture. This will include a 14-day test during which readings of discharge rates are being taken every hour. The new design, processes and test will ensure that every battery cell meets the highest quality and reliability standards.
To further improve reliability, Boeing, Thales and GS Yuasa will lower the highest charge allowed in the battery monitoring unit and charger and raise the lower level allowed for discharge. The battery charger will also be adapted to soften the charging cycle to put less stress on the battery during charging.
Inside the battery charger, each cell will be better insulated. An electrical insulator is being wrapped around each battery cell to electrically isolate cells from each other and from the battery case, even in the event of a failure. Electrical and thermal insulation installed above, below and between the cells will help keep the heat from the cells from affecting one another. This helps isolate it from the rest of the battery in the unlikely event that a cell fails.
The wire sleeving and the wiring inside the battery will be more resistant to heat and chafing, and the metallic bars that connect the eight cells of the battery will be attached with new fasteners that include a locking mechanism.
Small holes at the bottom of the battery case will allow moisture to drain away from the battery. Larger holes on the sides of the battery will allow a failed battery to vent with less effect on other parts of the battery.
Lastly, the battery will now be enclosed in sealed stainless steel. The enclosure isolates the battery from the rest of the equipment in the electronic equipment bays. It ensures that there can be no fire inside the enclosure, thus adding another layer of protection to the battery system. Any fumes or heat that build up in the enclosure will be vented outside the airplane. Testing to gain FAA approval of the battery enhancements has already started, with the FAA’s permission.
Before certification testing, during engineering testing, the team demonstrated that the new housing could safely contain the failure of all eight battery cells. The “ultimate” load is the equivalent of 1.5 times the maximum force ever expected to be encountered during a battery failure. The housing easily withstood this load and did not fail until pressure was at more than three times the ultimate load. In another test, the team demonstrated that fire cannot occur within the new enclosure. This means that even in the rare situation a battery does fail, the airplane can continue on safely to its scheduled destination. ME
Latest ISM Report: Growth
Slowing in Manufacturing
Economic activity in the manufacturing sector expanded in March for the fourth straight month, while the overall economy grew for the 46th consecutive month.
However, the rate of growth is slowing, according to the Manufacturing ISM Report on Business, which was released April 1 and surveys the nation’s top supply executives.
The PMI registered 51.3%. Readings below 50 indicate contraction, while those above 50 indicate expansion. While the March reading shows expansion, it also was down 2.9 percentage points from February’s reading of 54.2% and showed the strength of recent growth slowing.
That slow growth trend also was reflected in the New Orders Index, which registered 51.4%, and the Production Index, which registered 52.2%.
Overall, the ISM report for March was mixed. Seven indices showed growth—new orders, production, employment, prices, backlog of orders, exports and imports—but three showed contraction. The indices for supplier deliveries, inventories, customers’ inventories all registered below 50%.
Of the 18 manufacturing industries, 14 reported growth in March, down from 15 that showed growth in February. The March report can be found at http://tinyurl.com/MarchISMreport. ME
Nikon Metrology Inc. (Brighton, MI) on March 25 announced that Hajime Kosawa, managing director, has been promoted to a new position at Nikon Corporate in Japan. NMI now welcomes Dr. Hideaki Okamoto as the new managing director.
Koma Precision Inc. (East Windsor, CT) is now a distributor for live and static tools for Swiss machines for Citizen-Cincom, Ganesh, Hanwha, Nexturn, Star, Tornos, and Tsugami machines. More information at www.komaprecision.com.
DMG / Mori Seiki (Hoffman Estates, IL) on April 2 announced that Tyler Machine Tool Co. (Seabrook, NH and South Windsor, CT) would become a direct sales organization for the machine tool builder.
Liebherr Gear Technology Inc. (Saline, MI) has appointed Robert Jelic service manager overseeing North American operations for machine tool and automation systems.
In support of high schools in the Davidson and Mooresville, NC area, MSC Industrial Supply Co. (Melville, NY) recently sponsored Pine Lake Preparatory’s FIRST Team SPORK in the 2013 FIRST Robotics Competition. As a sponsor, MSC, a distributor of metalworking and maintenance, repair and operation supplies, provided students with the tools necessary to design, build and test components for their team’s robot. MSC also promoted careers in STEM. More at www.teamspork.com.
Methods Machine Tools (Sudbury, MA) has donated the use of a FEELER VMP-580 CNC vertical machining center and a FEELER HT30-Y turning center to Ivy Tech Community College’s Orthopedic and Advanced Manufacturing Training Center in Warsaw, IN, as part of their continued efforts to help train the country's workforce.
ThomasNet (New York, NY) has announced the launch of its North American Manufacturing Scholarship Program. Up to 30 graduating high school seniors with an interest in manufacturing careers will each receive a $1000 scholarship to pursue studies at a two- or four-year college or a vocational school. More at www.thomasnetscholarship.com.
ArcelorMittal USA (Burns Harbor, IN), part of the world’s leading steel and mining company, earned the 2013 Energy Star Award for Sustained Excellence, marking the company's sixth consecutive Energy Star Award.
CNC Software Inc. (Tolland, CT), developer of Mastercam, is celebrating its 30th anniversary. The company was founded in 1983 with a new programming concept for Computer-Numerical-Control, or CNC, machine tools. They developed a PC-based CAD/CAM software package with an emphasis on the CAM.
NewsDesk is edited by Editor-in-Chief Sarah A. Webster. Please email NewsDesk submissions to firstname.lastname@example.org.
This article was first published in the May 2013 edition of Manufacturing Engineering magazine. Click here for PDF.