787 Dreamliner investigation probes battery-charging electronics

  
FLAGSTAFF, Ariz.--Investigators from the U.S. National Transportation Safety Board(NTSB) arrived in Tucson, Ariz., Tuesday (Jan. 22) as the focus ofelectronics problems that have grounded Boeing's 787 Dreamlinershifted to battery-charging electronics.

The NTSB team is visiting SecuraplaneTechnologies, an avionics unit of U.K.-based Meggitt, totest the company's battery-charging devices as well as wire bundlesand battery-management circuit boards. Japanese and U.S. airlinesgrounded their 787s on Jan. 16 while investigators in both nationslooked into battery and other problems that have plagued theairliner in recent weeks.

The Dreamliner, a huge business andtechnology bet for Boeing, leverages advanced electronics, millionsof lines of software code and lithium ion battery technology toclaim 20 percent better fuel efficiency than the Boeing 767 it'sintended to replace.

The initialDreamliner probe focused on the LiOn battery, whichpowered the plane's auxiliary power unit (APU), after one (pictured nearby) caughtfire Jan. 7 in an empty plane in Boston. The incident has similarities to an incident involving the Chevrolet Volt--a Volt LiOnbattery in a crash-test vehicle caught fire in a parkinglot weeks after its test.

Investigators said they examined the 32V battery using X-ray and CTscans,  disassembled the APU battery into its eight cells fordetailed examination and documentation. Three of the cells wereselected for more detailed radiographic examination to view theinterior of the cells prior to their disassembly, the NTSB said in astatement. The agency added that an examination of theflight recorder data from the JAL B-787 airplane indicate that theAPU battery did not exceed its designed voltage of 32 volts.

Securaplane, acquired by Meggitt in 2011, has been in business since1986 and offers a variety of avionics including aircraftsecurity systems, LiOn batteries and chargers and inverters--thelast leveraging Vienna rectifiers, power MOSFETs/IGBTs, planartransformers, ultracapacitors, and advanced pulse width modulationtechniques, according to the company's web site.