Boeing knew it had a big problem with the lithium-ion batteries in its 787 Dreamliners well before a fire prompted safety inquiries and the worldwide grounding of its prize aircraft, the New York Times reports. Officials at All Nippon Airways, which has the world's largest fleet of 787s, say they had to replace 10 of the batteries in the months before the fire after they failed to charge properly or failed to connect with the electrical system.
The airline told Boeing about the problem but was not required to inform regulators because the battery trouble did not affect flights or present a safety problem. Japan Airlines says it had similar problems and National Transportation Safety Board investigators have now asked Boeing to provide a full operating history of the batteries, the AP reports. The Dreamliner remains grounded while regulators around the world investigate the problem.