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In the Boeing 787 Dreamliner's first year of service, at least four aircraft suffered from electrical system problems stemming from its lithium-ion batteries. Although teething problems are common within the first year of a new aircraft design's life, after a number of incidents including an electrical fire aboard an All Nippon Airways 787, and a similar fire found by maintenance workers on a landed Japan Airlines 787 at Boston's Logan International Airport, the United States Federal Aviation Administration (FAA) ordered a review into the design and manufacture of the Boeing 787 Dreamliner, following five incidents in five days involving the aircraft, mostly involved with problems with the batteries and electrical systems. This was followed with a full grounding of the entire Boeing 787 fleet, the first such grounding since that of the McDonnell Douglas DC-10 in 1979. The plane has had two major battery thermal runaway events in 52,000 flight hours, which was substantially less than the 10 million flight hours predicted by Boeing, neither of which were contained in a safe manner.〔(【引用サイトリンク】title=Accident: ANA B788 near Takamatsu on Jan 16th 2013, battery problem and burning smell on board )〕 The National Transportation Safety Board released a report on December 1, 2014, and assigned blame to several groups: * GS Yuasa of Japan, for battery manufacturing methods that could introduce defects not caught by inspection * Boeing’s engineers, who failed to consider and test for worst-case battery failures * The Federal Aviation Administration, who failed to recognize the potential hazard and did not require proper tests as part of its certification process ==Timeline== In December 2012, Boeing CEO James McNerney told media outlets that the problems were no greater than those experienced by the company with the introduction of other new models, such as the Boeing 777. However, on January 7, 2013, a battery overheated and started a fire in an empty 787 operated by Japan Airlines (JAL) at Boston's Logan International Airport. On January 9, United Airlines reported a problem in one of its six 787s with the wiring located in the same area as where the battery fire occurred on JAL's airliner; subsequently, the U.S. National Transportation Safety Board opened a safety probe. On January 11, 2013, the FAA announced a comprehensive review of the 787's critical systems, including the design, manufacture and assembly of the aircraft. U.S. Department of Transportation secretary Ray LaHood stated the administration was "looking for the root causes" behind the recent issues. The head of the FAA, Michael Huerta, said that so far nothing found "suggests (787 ) is not safe". Japan's transport ministry also launched an investigation in response. On January 16, 2013, an All Nippon Airways (ANA) 787 made an emergency landing at Takamatsu Airport on Shikoku Island after the flight crew received a computer warning of smoke present inside one of the electrical compartments. ANA said that there was an error message in the cockpit citing a battery malfunction. Passengers and crew were evacuated using the emergency slides. According to The Register, there are no fire-suppression systems in the electrical compartments holding batteries, only smoke detectors. US-based aviation regulators' oversight into the 2007 safety approval and FAA certification of the 787 has now come under scrutiny, as a key US Senate committee prepares for a hearing into the procedures of aviation safety certification "in coming weeks". However, an FAA spokesperson defended their 2007 safety certification of the 787 by saying, "the whole aviation system is designed so that if the worst case happens, there are systems in place to prevent that from interfering with other systems on the plane". On February 12, 2013 the Wall Street Journal reported that "Aviation safety investigators are examining whether the formation of microscopic structures known as dendrites inside the Boeing Co. 787's lithium-ion batteries played a role in twin incidents that prompted the fleet to be grounded nearly a month ago." On January 14, 2014, Japan Airlines said a maintenance crew at Narita Airport discovered smoke coming from the main battery of one of its Boeing 787 jets, two hours before the plane was due to fly to Bangkok from Tokyo. Maintenance workers found smoke and unidentified liquid coming from the main battery, and alarms in the cockpit indicated faults with the power pack and its charger. The airline said no other equipment was affected by the incident. The cause was not immediately known, and the airline is investigating the incident. In January 2014, a battery in a Japanese Airlines 787 emitted smoke from the battery's protection exhaust and partially melted while the aircraft was undergoing pre-flight maintenance. The cause of this latest incident remains under investigation. Soon after this incident, the Guardian noted that 'The agency (Federal Aviation Administration ) also launched a review of the design, manufacture and assembly of the 787 in January last year and said its report would be released last summer, but it has so far not released the report and has not responded to questions about when it will be finished.'〔(【引用サイトリンク】url=http://www.theguardian.com/business/2014/jan/14/boeing-787-dreamliner-japan-airlines-grounded-smoke-battery )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Boeing 787 Dreamliner battery problems」の詳細全文を読む スポンサード リンク
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