In 2013, just two years after it entered service, the Boeing 787 was grounded.
This move was prompted by electrical issues with the type’s lithium ion
battery for the aircraft's auxiliary power unit, or APU. After around three months,
the aircraft returned to service, with safety modifications made to the batteries and housing.
Let’s take a look back at these issues, their severity, and how they were ultimately resolved…
The first problem occurred on January 7th 2013, involving a Japan Airlines Boeing 787 parked at
Boston Logan International Airport. A battery on the aircraft overheated and started a fire.
Just two days later, United Airlines reported wiring problems with one of its 787s - in the
same area as the Japan Airlines aircraft fire. These incidents alone were enough for the US
National Transportation Safety Board to open an investigation.
However, less than 10 days later, on January 16th, things got worse.
An ANA 787 flying from Yamaguchi to Tokyo Haneda made an emergency landing at Takamatsu after the
crew received a warning about battery problems and experienced a burning smell in the cockpit.
The aircraft was evacuated after landing, and later investigation revealed a battery fire.
On the same day as the ANA fire,the US FAA issued an emergency airworthiness directive
ordering all Boeing 787 aircraft to be grounded pending further investigations.
Notably, this was the first grounding of a commercial aircraft type by the FAA since 1979.
Accounting for nearly half of 787 deliveries at the time,
Japanese carriers ANA and JAL voluntarily grounded their aircraft. The Japanese Transport Ministry
later formalized their airline’s groundings. in Europe, EASA grounded the 787. Additionally,
LAN, Qatar Airways, Ethiopian Airlines and Air India also grounded their aircraft.
The review focussed on the 787s lithium-ion batteries for the APU.
Initially, it was thought that overvoltage caused heating and fires,
but this was eventually ruled out. With a full NTSB investigation underway, the
interim solution for the aircraft was to encase the battery in a fireproof box and add venting
for any possible smoke. The battery voltage for charging was also reduced. With this done,
the FAA allowed US 787s to return to service from April 19th 2013. Other regulators did the same.
Concluding its investigation, a November 2014 NTSB report, explained:
"The probable cause of this incident was an internal short circuit within a cell
[cell 5 or cell 6] of the auxiliary power unit (APU) lithium-ion battery, which led
to a thermal runaway that cascaded to adjacent cells, resulting in the release of smoke and fire.
The incident resulted from Boeing's failure to incorporate design requirements to mitigate
the most severe effects of an internal short circuit within an APU battery cell."
The report blamed several parties: the Japanese battery manufacturer
for design issues, Boeing for failure
to consider and test battery failure, and the FAA for not requiring tests.
Lithium-ion batteries continue to be used in many aircraft. After the 787 issues,
Airbus considered switching batteries for the A350 to heavier nickel-cadmium batteries. Ultimately,
however, the European planemaker decided to also use lithium-ion batteries.
Do you remember these incidents taking place? Have you ever experienced a thermal runaway
situation with batteries on your own personal devices? Let us know by leaving a comment.