TP-EQUIV=”Content-Type” CONTENT=”text/html; charset=us-ascii”>
When a Cessna business jet equipped with lithium ion
batteries caught fire in 2011 while it was hooked up to a ground power unit,
Cessna and the Federal Aviation
moved swiftly to address the safety issues involved.
First the manufacturer advised owners of CJ4 aircraft to
replace the lithium ion batteries in the plane with older technology
nickel-cadmium or lead-acid batteries, and the FAA a few days later issued an
airworthiness directive making those replacements mandatory.
Those jets were back in the air a few weeks later once the
substitution was accomplished, albeit equipped with heavier, less capable
The Cessna lithium battery fire foreshadowed problems now
keeping Boeing’s newest airliner, the 787 Dreamliner, grounded after a
different type of lithium battery sparked fires aboard Dreamliners in Boston
and Japan in recent weeks.
Could Cessna’s reaction to its lithium battery problem
provide Boeing a clue how to move forward?
First, the company says, it needs to find out what’s going
The National Transportation Safety Board, Boeing, the FAA
and Japanese government investigators say they’re working ceaselessly to find
out why the batteries failed. Fifty Dreamliners are not flying, and Boeing is
delivering no more of the planes until the issue is solved. So far, there are
no definitive answers.
The safety board said its first round of investigation found
no evidence that the batteries in the
plane were overcharged, the most likely cause of the fire. Japanese
investigators say they too have found no cause for believing the batteries in a
Japan Air Lines plane that made an emergency landing there had lithium-ion
batteries that were overcharged.
Initial dissection of the batteries shows there might have
been a short circuit in one of the cells, but there is nothing definitive yet.
Reputation on the line
For Boeing and the airlines that bought the Dreamliner,
finding answers quickly and restoring the Dreamliner’s safety and reputation
are urgent priorities. The average list price for a Dreamliner is about $200
million, but airlines likely pay less. The groundings mean billions of dollars
in capital assets aren’t earning their keep, and Boeing isn’t bringing in
dollars for completed but undeliverable planes.
Boeing is keeping mostly mum about just exactly where their
investigation is leading, about what its alternatives might be and how long
clearing up the mystery and fixing it might take.
Most experts say solving the issue is likely to take weeks
and perhaps months more.
Experts speculate the investigation is leading in several
Such high-power batteries are particularly sensitive to manufacturing flaws.
Any foreign material could cause a short circuit inside the batteries, causing
the batteries to overheat and leading the thermal overrun to spread to other
cells. One cell in a battery involved in the
short-circuited. The two planes involved in the two incidents were relatively
new to commercial service.
The Japanese battery maker, GS Yuasa, says the batteries
weren’t defective. Investigators have toured the company’s plant. They’ve made
no pronouncements about whether the company’s products pass muster.
• Charging system problems. Boeing and government
investigators are talking with the
company, Securaplane Technologies, about its charging system. Overcharging the
batteries could cause a fire. Again, there’s been no public verdict on whether
the changing systems were working correctly, but the company has said it
believes it is blameless.
• Monitoring and safety systems. The FAA allowed
Cessna to pioneer the use of a different type of lithium-ion batteries in the
CJ4 under a special set of conditions that required sophisticated control and
monitoring systems for the batteries. Those elaborate safety systems were
designed to prevent conditions that would upset the chemistry of the batteries
and to isolate those batteries if they were failing. Special systems were
designed to vent smoke and fumes should batteries catch fire. No fire
suppression systems cover the lithium-ion batteries because putting out a fire
in them is nearly impossible and they simply are allowed to burn out. When
Boeing asked the FAA to use their lithium-ion batteries, the FAA crafted a set
of special conditions similar to those it had imposed on Cessna.
The NTSB said last week that those safety systems in the 787
had failed to operate as planned. That failure presents another issue for
Boeing, Once it corrects the issues that caused the fire, the company must then
address the safety systems’ defects.
Once Boeing and government investigators find and agree on
the cause of the problems, then they’ll have to create solutions.
Experts say those solutions range from relatively simple to