ANA discovers Dreamliner wiring problem

Japan's Transport Ministry said that an investigation into the overheating of a lithium ion battery in an All Nippon Airways (ANA) Boeing 787 discovered it had been improperly wired.

The Transport Safety Board said that the battery of the aircraft's auxiliary power unit (APU) was incorrectly connected to the main battery that overheated.

However, it added that a protective valve would have prevented power from the APU from doing any damage.

The safety board said that more analysis was needed to determine what had caused the plane's main battery to overheat and emit the smoke which forced the emergency landing of the ANA domestic flight and the worldwide grounding of Boeing 787 jets.