787 Batts Needed Replacing Before Incident
01-30-2013, 03:04 AM
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787 Batts Needed Replacing Before Incident
TOKYO—All Nippon Airways Co. 9202.TO +0.56% and Japan Airlines Co. 9201.TO +0.81% said they had replaced a series of batteries on their Dreamliner jets before an overheated battery on one ANA plane forced it to make an emergency landing and prompted the eventual grounding of all Boeing Co.'s BA -0.47% flagship 787s.
On Wednesday, ANA said during the roughly 14 months since it began flying the planes commercially, it replaced 10 of the lithium-ion batteries that are used to start the engines and power emergency systems—largely because of problems holding charges or providing sufficient power.
The carrier replaces batteries on its Boeing 777s—one of the workhorses of its fleet—at about the same rate, although the 777 batteries use a different nickel-cadmium technology, and are replaced for a mix of defects and routine maintenance swap-outs, ANA spokesman Ryosei Nomura said.
Enlarge Image
Reuters All Nippon Airways Boeing 787 Dreamliner planes line up at Haneda Airport in Tokyo.
It is not immediately clear whether ANA reported the replacement of its 787 batteries to Boeing, according to Mr. Nomura. The carrier didn't at the time tell Japanese authorities because the incidents didn't rise to the level of seriousness required for such reports, he said.
The ANA battery replacements were reported on Tuesday by the New York Times.
A JAL spokesperson said Wednesday that the carrier has also replaced some of its Dreamliner batteries, but didn't immediately have details on frequency or cause.
"Officially we can't comment as the NTSB has said this is now part of their investigation," Boeing spokesman Marc Birtel said.
The primary causes of replacement of the 787's batteries came after they were improperly disconnected, left to discharge without any other power sources on the aircraft—causing a deep discharge—or they expired, said a person familiar with the issue.
Regulators are focusing on maintenance of the Dreamliner batteries—including how often 787 operators in Japan and elsewhere had to replace the units—in order to shed some light on what caused batteries on two planes, one operated by ANA and the other by JAL, to overheat and burn in recent weeks, according to people familiar with the matter. The incidents led global regulators to ground all 787s on Jan. 16, until the batteries can be shown to be safe. Aviation investigators from the U.S. and Japan have been probing the production process of Kyoto-based battery maker GS Yuasa Corp., 6674.TO -0.91% as well as makers of the power units' chargers and circuitry in the U.S. and Japan, but so far have found no obvious problems or defects.
With the help of Boeing, these people said, investigators are gathering data about how often airlines replaced suspect or malfunctioning 787 batteries in the period leading up to the grounding. U.S. experts also are looking to collect information about unusual charging or discharging incidents recorded by those carriers, these people said.
In ANA's case, five of the 787 batteries, which use a powerful but flammable lithium-ion technology that has only recently been rolled out in commercial airplanes, were replaced because the units had lost their ability to hold a full charge, ANA's Mr. Nomura said. In three other cases, the batteries weren't able to provide sufficient power to the systems they were connected to. The reason for replacing the other two batteries wasn't immediately clear, Mr. Nomura said. In all but one of the 10 cases, the batteries were part of the unit that starts the Dreamliner's engines, rather than the unit that powers emergency systems.
In service, the primary causes of replacement of the 787's batteries often came as a result improper disconnection from the aircraft, or they were left to discharge without any other power sources on the aircraft—causing a deep discharge—or they had expired, said a person familiar with the issue.
One of the puzzling parts of the regulators' 787 probes has been that batteries examined so far on grounded aircraft haven't shown obvious signs of damage or malfunction, according to U.S. industry and government experts. Detailed checks of manufacturing records at the battery maker also haven't provided significant leads, they said.
On Tuesday, the safety board said Boeing "is providing pertinent fleet information, which will help investigators understand the operating history of lithium-ion batteries" on the 787 fleet.
Investigators previously determined that the main battery on the ANA jet was performing normally until shortly before a cockpit warning indicated a malfunction and the pilots smelled something burning, according to people knowledgeable about to the U.S. probe.
On Wednesday, ANA said during the roughly 14 months since it began flying the planes commercially, it replaced 10 of the lithium-ion batteries that are used to start the engines and power emergency systems—largely because of problems holding charges or providing sufficient power.
The carrier replaces batteries on its Boeing 777s—one of the workhorses of its fleet—at about the same rate, although the 777 batteries use a different nickel-cadmium technology, and are replaced for a mix of defects and routine maintenance swap-outs, ANA spokesman Ryosei Nomura said.
Enlarge Image
Reuters All Nippon Airways Boeing 787 Dreamliner planes line up at Haneda Airport in Tokyo.
It is not immediately clear whether ANA reported the replacement of its 787 batteries to Boeing, according to Mr. Nomura. The carrier didn't at the time tell Japanese authorities because the incidents didn't rise to the level of seriousness required for such reports, he said.
The ANA battery replacements were reported on Tuesday by the New York Times.
A JAL spokesperson said Wednesday that the carrier has also replaced some of its Dreamliner batteries, but didn't immediately have details on frequency or cause.
"Officially we can't comment as the NTSB has said this is now part of their investigation," Boeing spokesman Marc Birtel said.
The primary causes of replacement of the 787's batteries came after they were improperly disconnected, left to discharge without any other power sources on the aircraft—causing a deep discharge—or they expired, said a person familiar with the issue.
Regulators are focusing on maintenance of the Dreamliner batteries—including how often 787 operators in Japan and elsewhere had to replace the units—in order to shed some light on what caused batteries on two planes, one operated by ANA and the other by JAL, to overheat and burn in recent weeks, according to people familiar with the matter. The incidents led global regulators to ground all 787s on Jan. 16, until the batteries can be shown to be safe. Aviation investigators from the U.S. and Japan have been probing the production process of Kyoto-based battery maker GS Yuasa Corp., 6674.TO -0.91% as well as makers of the power units' chargers and circuitry in the U.S. and Japan, but so far have found no obvious problems or defects.
With the help of Boeing, these people said, investigators are gathering data about how often airlines replaced suspect or malfunctioning 787 batteries in the period leading up to the grounding. U.S. experts also are looking to collect information about unusual charging or discharging incidents recorded by those carriers, these people said.
In ANA's case, five of the 787 batteries, which use a powerful but flammable lithium-ion technology that has only recently been rolled out in commercial airplanes, were replaced because the units had lost their ability to hold a full charge, ANA's Mr. Nomura said. In three other cases, the batteries weren't able to provide sufficient power to the systems they were connected to. The reason for replacing the other two batteries wasn't immediately clear, Mr. Nomura said. In all but one of the 10 cases, the batteries were part of the unit that starts the Dreamliner's engines, rather than the unit that powers emergency systems.
In service, the primary causes of replacement of the 787's batteries often came as a result improper disconnection from the aircraft, or they were left to discharge without any other power sources on the aircraft—causing a deep discharge—or they had expired, said a person familiar with the issue.
One of the puzzling parts of the regulators' 787 probes has been that batteries examined so far on grounded aircraft haven't shown obvious signs of damage or malfunction, according to U.S. industry and government experts. Detailed checks of manufacturing records at the battery maker also haven't provided significant leads, they said.
On Tuesday, the safety board said Boeing "is providing pertinent fleet information, which will help investigators understand the operating history of lithium-ion batteries" on the 787 fleet.
Investigators previously determined that the main battery on the ANA jet was performing normally until shortly before a cockpit warning indicated a malfunction and the pilots smelled something burning, according to people knowledgeable about to the U.S. probe.
02-12-2013, 02:44 AM
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787 Battery
NTSB Identifies Short Circuit on 787 Battery
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. “After an exhaustive examination of the JAL [Japan Air Lines] lithium-ion battery, which was composed of eight individual cells, investigators determined that the majority of evidence from the flight data recorder and both thermal and mechanical damage pointed to an initiating event in a single cell,” she said. “That cell showed multiple signs of short circuiting, leading to a thermal runaway condition, which then cascaded to other cells. Charred battery components indicated that the temperature inside the battery case exceeded 500 degrees Fahrenheit.” The cause of the short circuit is still unknown, although investigators have ruled out some typical lithium-ion battery faults such as physical damage to the unit itself and circuit shorts initiated by an external source. The NTSB is still considering potential overcharging of the units, as well as possible manufacturing faults.
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. “After an exhaustive examination of the JAL [Japan Air Lines] lithium-ion battery, which was composed of eight individual cells, investigators determined that the majority of evidence from the flight data recorder and both thermal and mechanical damage pointed to an initiating event in a single cell,” she said. “That cell showed multiple signs of short circuiting, leading to a thermal runaway condition, which then cascaded to other cells. Charred battery components indicated that the temperature inside the battery case exceeded 500 degrees Fahrenheit.” The cause of the short circuit is still unknown, although investigators have ruled out some typical lithium-ion battery faults such as physical damage to the unit itself and circuit shorts initiated by an external source. The NTSB is still considering potential overcharging of the units, as well as possible manufacturing faults.
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