In a February 7 news conference, NTSB chairman Deborah Hersman explained the latest findings on the battery problem that resulted in the grounding of the Boeing 787 fleet three weeks ago.
EaglePicher Technologies expects to certify a lithium-ion main-ship aircraft battery by year-end, according to Ron Nowlin, vice president and general manager of EaglePicher Aerospace Systems. The battery has been selected for a jet, but Nowlin was unable to reveal the OEM and said he “cannot confirm” news reports “that we are doing any work for Cessna.”
As U.S. National Transportation Safety Board investigators continued their painstaking examination of the lithium-ion battery that caught fire on February 7 in a Japan Airlines Boeing 787, the airplane’s manufacturer projected a business-as-usual posture during its fourth-quarter earnings call last Wednesday.
The subject of fires caused by lithium-ion batteries took on urgent new meaning following two thermal runaway incidents with lithium-ion batteries installed in Boeing’s 787 Dreamliner. A lot of information—and misinformation—surrounds lithium-ion technology, and experts from all over are weighing in with their opinions.
The Cessna Citation CJ4 is currently the only business jet certified with (but no longer flying with) a lithium-ion main-ship battery, using lithium-iron phosphate, not the lithium-cobalt oxide battery found on the Boeing 787, which is currently grounded in the wake of battery fires.
Investigations of separate incidents involving Boeing 787s in the U.S. and Japan appear to concur that the batteries that burned in each case did not overcharge. But investigators continue to seek causes for the two incidents that led to the grounding of the worldwide 787 fleet. The probes remain focused on the eight-cell lithium-ion batteries manufactured by Japan’s GS Yuasa for Thales, which supplies the 787’s electrical power conversion system.
The damaged lithium-ion APU battery from the Japan Air Lines Boeing 787 that caught fire on January 7 while parked at Boston’s Logan Airport experienced an uncontrolled chemical reaction known as a “thermal runway” and short circuiting, but the cause and sequence of these events are still unknown, according to the U.S. National Transportation Safety Board (NTSB).
Since October last year there have been 132 incidents involving battery overheats or fires aboard aircraft, according to the FAA. Until the recent series of Boeing 787 incidents, most fires occurred in cargo containers or personal electronic devices carried in the cabin.
Data from the flight recorder retrieved from the Japan Air Lines Boeing 787 that caught fire on January 7 while parked at Boston Logan International Airport shows that the airplane’s APU battery did not charge beyond its design limit of 32 volts, according to the U.S. National Transportation Safety Board.
Airlines around the world have grounded their Boeing 787s following the U.S. Federal Aviation Administration’s Wednesday emergency airworthiness directive (AD) that requires United Airlines to stop flying its six Dreamliners until it demonstrates the safety of the airplanes’ bat