US safety investigators are examining battery of a Japan Airlines' 787 that caught fire in Boston last monthThe US's top transportation safety investigator has questioned the "assumptions" regulators used before clearing Boeing's use of controversial lithium-ion batteries on its grounded 787 Dreamliner.The national transportation safety board (NTSB) has been investigating the battery of a Japan Airlines 787 that caught fire at Boston's Logan airport in January.NTSB chairwoman Deborah Hersman told reporters on Thursday that tests showed a failure in a single cell of the battery spread to the ... Read More