No full description of the process by which Boeing engineered and tested its lithium-ion battery has been disclosed, but emerging details show how regulators relied heavily on Boeing to do most of the work on what the FAA acknowledged from the start would be a potentially dangerous technology.
The FAA approved “special conditions” for the 787 battery in 2007, acknowledging risks including “Flammability of Cell Components.”
“Safe cell temperatures and pressures must be maintained during any foreseeable charging or discharging condition and during any failure of the charging or battery monitoring system not shown to be extremely remote,” the first condition reads. “Extremely remote” is FAA code for once in 10 million flight hours.
Special conditions do not include specific tests, so Boeing itself proposed them to the FAA. Designees could approve the design of tests and monitor the tests themselves, though the FAA told Reuters its staff also had approved the testing program and observed testing.
A Boeing presentation in February described “baking the battery to induce overheating, crush testing and puncturing a cell with nail to induce short circuit.”
At the same time the FAA approved the special conditions in 2007, FAA staff and the aircraft manufacturing industry, including Boeing, were devising lithium-ion battery tests that included all the details the special conditions lacked.
Published in 2008 and adopted by the FAA three years later, the standard known as RTCA DO-311 gave precise instructions for tests. The worst-case-scenario test required turning off all failsafe electronics, short-circuiting the battery and watching for flames for three hours.
Boeing did not run those tests. “The RTCA standards were not designed for the 787,” and Boeing provided extensive testing to show the 787 met the special conditions, spokesman Marc Birtel said.
The FAA acknowledged the batteries were potentially flammable in the special conditions approved. Said former Inspector General Schiavo, “They knew they had problems. They just said ‘OK.’”