The National Transportation Safety Board (NTSB) on Friday said Boeing 787 Dreamliner tests should have discovered the risk of smoke and fire. The tests were approved by the Federal Aviation Administration (FAA).
The NTSB investigated the company after a battery fire grounded the Dreamliner in January 2013. The battery fire started after one of eight battery cells that make up the planes backup lithium-ion battery failed. The battery is used to power the Dreamliner when all other power sources fail.
According to the agency, the single cell short circuited and led to a thermal runaway — a chemical reaction in which rising temperature leads to increasing temps which then spread to the rest of the battery.
An investigation by the NTSB revealed that short circuiting did not cause the Dreamliner problems.
According to Deborah Hersman, chairwoman of the NTSB:
“Boeing has indicated that these tests that were conducted prior to certification showed no evidence of cell-to-cell propagation or fire in the battery. However, our investigative findings with respect to the event battery show that when a short circuit did occur, it resulted in cell-to-cell propagation in a cascading manner and a fire.”
During its own testing, Boeing found “smoke emission” from one cell issues would occur in less than one out of every 10-million flight hours. That very instance occurred after just 100 thousand flight hours. In fact, two flights have experienced smoke emission, and one of those events resulted in a fire.
The NTSB is now demanding that Boeing review the battery problem and also its testing, which provided false conclusions.
According to Hersman:
“The assumptions used to certify the battery must be reconsidered. As we move forward, we will begin testing of some of the batteries that have been removed from the 787 fleet from the field. The NTSB will also examine the safety certification process used by both the FAA and Boeing for the 787 battery design and determine why the hazards identified in this investigation were not mitigated.”
Boeing says it is eager to work with the FAA to fix any issues involving its highly sought after Boeing 787 Dreamliner.