On 25 November 2011, a Saab Aircraft Company S340B was being
operated on a scheduled passenger service from Lismore to Sydney,
New South Wales (NSW). During the taxi to the gate after arrival at
Sydney, a cabin crew member noticed smoke coming from near a
passenger seat and instructed the passenger to throw the source of
the smoke into the aisle. The cabin crew member then discharged a
fire extinguisher onto what was later identified as a mobile
telephone. After several minutes, the smoke cleared.
An Australian Transport Safety Bureau (ATSB) investigator
travelled to Sydney airport to commence an investigation into the
event. The mobile telephone was transported to the ATSB technical
facilities in Canberra for initial examination and then forwarded
to the United States for detailed examination at a specialist
facility.
The technical examinations found that a small metal screw had
been misplaced in the battery bay of the mobile telephone; the
screw puncturing the battery casing and causing an internal short
circuit leading to heating and thermal runaway. It was probable
that the screw had been misplaced during an earlier repair carried
out on the telephone. That repair had not been conducted by an
authorised service provider.
This investigation highlights the risks associated with the use
of non-authorised agents for the repair of lithium battery-powered
devices, and reinforces the Civil Aviation Safety Authority (CASA)
recommendations that these devices should be carried in the cabin
and not in checked-in baggage.