787 Batteries Had Prior Problems

The International Herald Tribune

January 31, 2013

Even before two battery failures led to the grounding of all Boeing 787 jets, the lithium-ion batteries used on the aircraft had experienced several problems that raised questions about their reliability.

Executives at All Nippon Airways, the biggest operator of the jets, said during an interview this week that the carrier had replaced 10 of the batteries in the months before fire and smoke in two cases caused regulators around the world to ground the jets.

The airline said that it had told Boeing of the replacements as they occurred but that it had not been required to report them to safety regulators because no flights were canceled. Officials at the U.S. National Transportation Safety Board (NTSB) said those battery replacements were now part of their inquiry.

The airline also explained, for the first time, the extent of the previous problems, which added to concerns about whether Boeing and other plane makers could use them safely.

In five of the 10 replacements, All Nippon said the main battery had shown an unexpectedly low charge. An unexpected drop in the charge of a 787's main battery also occurred on the All Nippon flight that made an emergency landing in Japan on Jan. 16.

The airline also revealed that in three instances the main battery failed to start normally and had to be replaced, along with the charger. In other cases, one battery showed an error reading and another, used to start the auxiliary power unit, failed. All of the events occurred from May to December of last year. The malfunctioning batteries, made by the Japanese manufacturer GS Yuasa, were serviced by All Nippon maintenance crew members.

Japan Airlines, which operates seven 787s, said Wednesday that there had been ''several cases'' in which maintenance crew members needed to replace 787 batteries after irregularities, but the carrier declined to give details. The actions were not considered a safety risk and were conducted ''within the scope of regular maintenance,'' said Kazunori Kidosaki, a company spokesman.

Kelly Nantel, a spokeswoman for the NTSB, said investigators had only recently heard that there were ''numerous issues with the use of these batteries'' on 787s. She said the board had asked Boeing, All Nippon and other airlines for information about the problems.

''That will absolutely be part of the investigation,'' she said.

On Wednesday, Boeing reported a fourth-quarter profit that topped analyst estimates and said it did not expect the recent problems with the batteries on the 787 to have a significant effect on its earnings this year.

W. James McNerney Jr., the chief executive of Boeing, said in a statement that fixing the battery problems was the company's ''first order of business for 2013.'' And even though the planes have been grounded and Boeing has temporarily halted deliveries, the company said it still planned to deliver 60 of the planes this year.

Rob Stallard, an analyst with RBC Capital Markets, wrote in a note to investors that the company's forecast for 787 deliveries was lower than the 93 he had expected.

Boeing, based in Chicago, said its net profit in the fourth quarter was $978 million, or $1.28 a share. That was 9 cents a share higher than the average analyst estimate. Still, profit was down 30% from the $1.39 billion, or $1.84 a share, in the quarter a year earlier, when a favorable tax settlement lifted earnings.

Boeing said its revenue rose 14% in the fourth quarter, to $22.3 billion from $19.55 billion a year earlier.

Boeing has said repeatedly that any problems with the batteries can be contained without threatening the planes and their passengers.

Boeing executives said the fact that problems were identified and the batteries successfully replaced also suggested that safeguards were activated to prevent overheating and keep the drained batteries from being recharged. They said the batteries could drain too deeply if left on without being connected to power sources. Trying to recharge such batteries could generate excessive heat, so safety mechanisms lock out any attempts to do that.

The executives said that improperly connecting a battery could also render it unusable. And they acknowledged that some of the new batteries were not lasting as long as intended. They said this could require airlines to replace them more frequently but did not pose a safety problem.

A GS Yuasa executive, Tsutomu Nishijima, said battery exchanges were part of the normal operations of a plane but would not comment further.

The U.S. Federal Aviation Administration (FAA) decided in 2007 to allow Boeing to use the lithium-ion batteries instead of older, more stable types as long as it took safety measures to prevent or contain fires. But once Boeing put in those safeguards, it did not revisit its basic design even as more evidence surfaced of the risks involved, regulators said.

In a little-noticed test in 2010, the FAA found that the kind of lithium-ion chemistry that Boeing planned to use—lithium cobalt—was the most flammable of several possible types. The test found that that type of battery provided the most power, but could also overheat more quickly.

And in 2011, a lithium-ion battery on a Cessna business jet started smoking while it was being charged, prompting Cessna to switch to traditional nickel-cadmium batteries.

The U.S. safety board said Tuesday that it had still not determined what caused a fire Jan. 7 on a Japan Airlines 787 that was parked at Logan International Airport in Boston. The fire occurred nine days before the All Nippon jet made an emergency landing when pilots smelled smoke in the cockpit. That battery was later sent to its maker, GS Yuasa.

U.S. regulators said it was also still possible that flaws in the manufacturing process could have gone undetected and caused the recent incidents.

GS Yuasa X-rays each battery before shipping it to look for possible defects. But some battery experts said that scans might be unable to detect minute anomalies in the battery, like microshavings trapped in the tightly wound conductive material used in each battery's eight cells.

So far, Boeing appears reluctant to consider alternatives. Lithium-ion, experts say, is particularly attractive because it packs more power in a smaller size, and is therefore lighter than more traditional battery designs. For that reason, it is now widely used in personal electronics and is finding greater acceptance in other industries, like electric cars.

Unless investigators can find the precise cause of the 787's battery problems or how to prevent them, some experts say Boeing may have little choice but to use more traditional battery designs to restore confidence in its airplanes.

Switching batteries would come at a steep cost, and would probably entail months of engineering work as well as new certification by regulators. It would also go against the efforts by other manufacturers, including Airbus and Gulfstream, to adopt lithium-ion batteries in their planes.

Regulators have long known about the potential dangers of lithium-ion batteries, which can overheat and ignite—a condition known as thermal runaway—if improperly charged or discharged. For that reason, the batteries are integrated into a sophisticated electronic system that is intended to monitor the battery and prevent it from overcharging.

The FAA 's battery tests in 2010 highlighted the hazards of lithium-cobalt batteries. When they overheat, the batteries show ''much more severe increases in temperature and pressure'' than other battery types.

Another risk of lithium batteries also became apparent with the Cessna episode in 2011, when a technician working on a new model, the CJ4, hooked up the plane to a power source to recharge the battery and soon after saw smoke coming out of it.

According to a government safety official with knowledge of the Cessna incident, the battery had drained to less than 5% of its charge. The problem with lithium batteries, however, is that recharging a battery that has been drained to a low point can create a risk of fire because the battery is unable to accept a charge. Recharging it then creates excessive heat and can cause it to ignite.

After discussions with the FAA, Cessna decided to replace the battery on its planes with nickel-cadmium batteries, which are heavier but do not catch fire easily. Boeing has said its system has safeguards that prevent a drained battery from being recharged without first being sent back to the manufacturer for reconditioning.

A Cessna spokesman declined to comment about the incident.

According to investigators in Japan, the battery on the All Nippon jet that made the emergency landing showed a stable reading of 31 volts, near its full charge capacity, until 15 minutes into the flight, when pilots detected an odd smell. Right about then, sensors detected a sudden unstable discharge of the battery to near zero for reasons that the Japanese investigators still cannot explain.