Airbus has
set a taskforce to monitor all data, information and safety improvements related
to the in-flight fire in hazardous Li-ion batteries that has spoiled and forced
the 8 airlines -that has received 50 aircraft- and regulatory agencies –with American
FAA leading them- to ground the complete 787 fleet.
Because it is not only an
issue with the electrical systems but a series of incidents, as the 787 grounding
is the first one for many years (the last time the FAA issued this type of
order grounding a jetliner model occurred after a DC-10 lost an engine and
crashed in 1979). The FAA called for Boeing and its airline customers "to
develop a corrective action plan" and Boeing is working around the clock
to resume the flights as quickly as possible.
Boeing confirmed that a fire on two JAL & ANA 787s
appeared to have started in a battery, and the National Transportation Safety
Board said the battery had "severe fire damage." The fire happened on
the ground 7/January, with no passengers on board JAL 787. Only a week later
another 787, this time from ANA, made an emergency landing in southern Japan
after battery alarm and smoke. The key is that in-flight fires can be
catastrophic, so the matter is getting close scrutiny by aviation authorities.
A350 XWB has
also lithium-ion batteries, which is considered hazardous in many applications
and in air cargo shipping. While the 787′s use of Li-ion is attracting
headlines, the use in airplane applications is more common than has been
recognized.
The Airbus
A380 uses lithium batteries to power its emergency lighting system. The US FAA
set special conditions when certifying the aircraft. Airbus says “the batteries
are small, limited, and are not in a frequently-active charging/discharging
function.” And the Airbus A350 will have Lit-ion batteries as can be read in
the website:
“Airbus also
has looked at new ways to generate electricity aboard the aircraft itself. The
A350 XWB features a new lithium-ion battery that marks a significant
improvement on the Cd-Ni unit used in other models. The battery contains less
hazardous material, which makes it safer to handle. Adding to the benefits, it
has a higher power and energy density, and low maintenance requirements, all
while lasting up to three times longer than the Cd-Ni.”
So the reason
for equipping the 787 and the A350 XWB with batteries is the same: improve fuel
efficiency, reduce maintenance costs/time and reduce weight.
The batteries are used for the following functions:
- No-break power transfer function
- DC power to the instrument buses in a standby power configuration
- DC power or various ground functions, including APU start when ground power is not available.
The A350 XWB has 4 identical part number 28V Lithium-Ion
batteries from Saft, meaning
there are 28 Li-ion cells on-board (compared with only 14 on the 787). Airbus
electrical systems engineers have studied the known failure mode for Li-ion
batteries called thermal runaway.
Only 2 of the 4 batteries are connected to the buses in a
way such that they can supply standby DC power in an emergency. The battery system offers a truly
innovative solution and includes an integrated monitoring and charging system
using proprietary Saft know-how in the relevant electrochemistry algorithms.
Currently, and this could be modified, the electronics bay –where relatively few
flammables are installed- doesn’t have a fire suppression system.
Airbus CEO Brégier:
“We went through discussions with the regulatory agencies – EASA [European
Aviation Safety Agency] and FAA [Federal Aviation Administration] – and they
seemed happy with the [A350 electrical] architecture,” he said. “Regarding the
A350, we’re in the development phase. We will have many opportunities to change
things. With regard to the electric architecture, we see, unless we receive new
information, no need to change the architecture.” “Both Boeing and Airbus give
the same priority to safety,” affirmed Brégier.
The
announcement “There is no Boeing 787 flying anywhere in the world at the moment"
shocked the aerospace industry and it is
not good for the A350 XWB because the public confidence in the fleet of 787 or
any aircraft needs to be restored and it will take time.
Based on the
article “All Boeing Dreamliners Are Grounded World-Wide” published in The Wall
Street Journal
"the electronics bay –where relatively few flammables are installed- doesn’t have a fire suppression system"
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