CRI英语听力2013年02月（WORD文本）：LONG-ROAD-AHEAD-FOR-DREAMLINERS-BATTERIES-PROBE_61.doc

1、U.S. safety regulators say they have a long road ahead in their investigation into the lithium ion battery problems on Boeings 787 Dreamliners.The head of the National Transportation Safety Board says they will file their interim findings in 30 days.Deborah Hersman says investigators have pinpointed

2、 the origin of a battery fire on a 787 in Boston last month.However, investigators have not yet determined the cause of the short circuit which led to the fire.Hersman says Boeing is going to have to review its use of this particular battery technology.Boeing assessed that the likelihood of a smoke

3、emission event from a 787 battery would occur less than once in every 10 million flight hours. The 787 fleet has accumulated less than 100,000 flight hours, yet there have now been two battery events resulting in smoke less than two weeks apart on two different aircraft. This investigation has demon

4、strated that a short circuit in a single cell can propagate two adjacent cells and result in smoke and fire. The assumptions used to certify the battery must be reconsidered.The 50 Dreamliners in service have been grounded since January 16th due to the battery failures.The Federal Aviation Administration has carried out a test flight of a 787 to see if any battery problems crop up.Boeing is reportedly trying to find ways to mitigate and contain a fire if one starts in the batteries.None of the 787s on-order for Chinese airlines has yet to be delivered.