On Tuesday, investigators will convene in Tucson, Arizona to test and examine the charger for the battery, and download non-volatile memory from the APU controller, with similar tests planned at the Phoenix facility where the APUs are built. Other components have been sent for download or examination to Boeing’s Seattle facility and manufacturer facilities in Japan.
Securaplane Technologies Inc, a unit of Britain’s Meggitt Plc that makes the charger, said it will fully support the U.S. investigation.
Officials with United Technologies Corp, which builds the plane’s auxiliary power unit and is the main supplier of electrical systems on the 787, said they would also cooperate with the investigation.
The NTSB’s decision to travel to Securaplane’s facility sparked fresh questions about the safety of the lithium-ion batteries that remain at the heart of the investigation.
While the 787 is the most aggressive user of lithium-ion battery technology in commercial aviation, the industry at large is testing it, and the FAA has approved its use in several different planes, each governed by “special conditions.”
“Lithium-ion batteries are significantly more susceptible to internal failures that can result in self-sustaining increases in temperature and pressure,” the FAA said in 2006, when it allowed Airbus to use lithium batteries for the emerging lighting system on its A380.
Securaplane, which first began working on the charger in 2004, suffered millions of dollars of damages in November 2006 after a lithium-ion battery used in testing exploded and sparked a fire that burned an administrative building to the ground.
Boeing spokesman Marc Birtel said an investigation into the 2006 fire was later determined to have been caused by an improper test set-up, not the battery design. He declined comment on the current 787 investigations.
After the fire, a former Securaplane employee named Michael Leon sued the company, alleging that he was fired for raising security concerns about charger and discrepancies between their assembly documents and the finished chargers.
Leon’s suit was later dismissed.