Boeing’s chief executive said the company is working around the clock investigating a battery problem that has grounded 787 Dreamliners worldwide, saying the company “will get to the bottom of it.” The comments come two weeks after the fleet was grounded, and concern is growing on the cost to airlines with earth-bound airplanes, and to the reputation of the airplane and Boeing itself.
Company president and CEO Jim McNerney was predictably optimistic, even upbeat, during a quarterly earnings call that focused heavily on the investigation by Boeing, the FAA and others. Hundreds of experts from around the world are working with Boeing to determine just what led to two battery fires aboard Dreamliners earlier this month. Although the problem prompted the grounding of all 50 Dreamliners in service, and many — including Tesla Motors and SpaceX CEO Elon Musk — have been critical of Boeing’s use of lithium-ion batteries, the company continues building Dreamliners even as investigators work around the clock to find the root cause of the problem.
“We will get to the bottom of it, and in so doing will restore confidence in the 787,” McNerney said Wednesday. He added that the company continues to believe in the use of lithium-ion batteries that are critical to the design of 787, the most electric airliner to ever fly. “We feel good about the battery technology and the fit for the airplane.”
McNerney remains confident the company will determine just what led to “thermal runaway” events aboard two Dreamliners. The first occurred in Boston on January 7 when a battery caught fire after passengers had deplaned. The second came one week later when smoke from a burning battery forced a pilots to make an emergency landing in Japan. The result has been the first grounding of a U.S. airplane commercial airline fleet since 1979. And despite the optimism from Boeing, there is no indication from investigators or the Federal Aviation Administration that the grounding will be lifted any time soon.
Outside of Boeing, some are less optimistic that Boeing used the right design for its lithium-ion batteries, which the aircraft manufacturer chose for their energy density. Musk, whose companies use lithium-ion batteries extensively, has been among the most vocal.
“Unfortunately, the pack architecture supplied to Boeing is inherently unsafe” Musk wrote in an email to Flightglobal. “Large cells without enough space between them to isolate against the cell-to-cell thermal domino effect means it is simply a matter of time before there are more incidents of this nature.”
Boeing uses a 63-pound Li-ion battery largely as a backup power source for several systems within the Dreamliner, which is among the most technologically advanced passenger aircraft ever built. The batteries, like those in the Tesla Roadster and Model S automobiles and aboard SpaceX rockets, use cobalt oxide chemistry for maximum power density. But Tesla and SpaceX use battery packs comprised of thousands of cylindrical 18650 cells, each roughly the size of a AA battery. The cells have been refined through more than 15 years of manufacturing and use in consumer products such as laptops and power tools. Tesla and SpaceX closely control the charging, output and temperature of the cells using a sophisticated power management system.
The lithium-ion battery used by Boeing is comprised of just eight cells housed in a single container. Musk says Tesla and SpaceX engineers isolate the cells to prevent a fire in one from spreading to others. He is critical of Boeing’s design, saying the size and packaging of the cells makes thermal runaway in one or more cells much more likely to result in the entire pack catching fire.
Musk is not alone in raising these issues. The relatively simple looking design of the Boeing battery, manufactured by the Japanese firm GS Yuasa, immediately caught the attention of lithium-ion battery expert Dr. K.M. Abraham. Abraham has been researching and producing lithium-ion batteries since 1976 and says proper design is critical for both power output and safety.
“It did not look like a sophisticated battery pack to me” Abraham said of his first impression after seeing a photo of a Dreamliner battery. The 32-volt Boeing battery uses eight 3.7 volt cells housed in a single metal container.
The manufacturing process is also a major concern, according to Abraham. The 18650 cells used by Tesla and others experienced quality control problems early on, and it was more than a decade before the design and manufacturing was refined. These days, failure rates are extremely low — less than one in a million, said Abraham. He agrees the design used by Tesla reduces the chance of a thermal runaway resulting in a larger event.
“They use a smaller cell approach, but I think it is a much safer way of doing that,” he said of Tesla. “They use a modular construction. Once a cell goes, it is isolated, there is no large runaway.”
The National Transportation Safety Board released more information about its investigation and examination of the batteries aboard the plane that caught fire in Boston. Last week the agency said it found evidence of a short in the charred remains of the battery that caught fire. This week, the NTSB is continuing its examination with a microscopic look at the region affected by the internal short circuit and thermal damage. The agency is also looking at a second undamaged battery in the plane. It is looking for any evidence of “in-service damage and manufacturing defects.”
The NTSB did say it found no problems with charger unit used with the batteries on the Boston 787 or the auxiliary power unit.
All Nippon Airways, which was the first to buy Dreamliners, says it replaced 10 of the batteries on its fleet of 17 Dreamliners in the months leading up to the Dreamliner’s grounding. The airline says it notified Boeing of the battery replacements, but did not tell safety regulators because the bad batteries showed low charge and other performance issues and were not considered a safety issue according to The New York Times.
McNerney acknowledged today that the replacement rate of Dreamliner batteries was “slightly higher” than anticipated, but emphasized the batteries were replaced for maintenance reasons, not safety concerns. The comment was largely a response to a story in the Seattle Times that said Boeing had to return more than 100 of the lithium-ion batteries to GS Yusasa. The $16,000 batteries were returned because they had been run down and could not be recharged. Some of the batteries had exceeded their expiration date, but many were losing capability much earlier than expected according to the Times. It is unclear how many batteries needed to be replaced because of quality problems, or how many were replaced due to the design which shuts down the battery in the event it is drained too far.
The 32-volt batteries have a cutoff system that effectively shuts down the battery if the charge falls below 15 percent. Normally the system is designed to prevent this from happening, but as is the case with a flashlight or car door, if something is accidentally left on in a 787 and is drawing battery power, the 63 pound batteries can reach that critical 15 percent cutoff.
Boeing continues to assuring customers and shareholders that the problem will be resolved soon. It said production on both 787 assembly lines continues, and the company believes it will increase production to its scheduled rate of 10 airplanes monthly by year’s end.
The eight airlines with grounded Dreamliners continue to shuffle other aircraft to try and make up for the missing seats in their fleet. ANA is using 777s for some of its 787 routes, while United has brought in 737s for domestic flights that were using the Dreamliner and is also using 777s on longer international flights.
Boeing's Batteries Draw Criticism as Dreamliner Probe Continues
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Boeing's Batteries Draw Criticism as Dreamliner Probe Continues
