BEIJING, Feb. 8 (Xinhuanet) -- After four weeks of investigation, the US National Transportation Safety Board has identified how, but not why, a battery fire on a Boeing 787 Dreamliner occurred last month.

Deborah Hersman, chairwoman of National Transportation Safety Board, said, "We have pinpointed the origin of the event to cell number 6. We know cell number 6 had multiple short-circuits, and so we’ve identified the initiating event as a short-circuit in cell number 6."

The NTSB also said that the decision to return the Boeing 787 fleet to flight will be made by the Federal Aviation Administration. The announcement came after the FAA grounded the 787s after a battery in a Airlines plane caught fire, and an All Nippon Airways flight had a battery malfunction.

Boeing 787 is the first mid-sized passenger plane capable of long-distance flight. But problems appeared soon after the planes were put into operation, including fuel leaks, inflamed batteries, and engine problems.

(Source: CNTV.cn)