Safety officials from the Federal Aviation Authority have joined Japanese counterparts in an examination of the
Boeing Dreamliner which made an emergency landing because of a fault earlier this week.
Boeing representatives are also on site at Takamatsu airport in western Japan as the examination of the All Nippon Airways aircraft continues.
The investigation is being led by the Japan Transport Safety Board.
The pilot of the plane was forced to make an emergency landing on Wednesday after he smelled burning and received a cockpit warning of battery problems.
All passengers evacuated the plane on emergency slides.
Following the incident the FAA joined the Japanese Transport Safety Board in calling for the grounding of the aircraft.
All 50 of the flagship Dreamliners were subsequently taken out of service.
It is the first major aircraft grounding since 1979.