An official with Japan’s transport safety board says four U.S. officials, including two Boeing Co. representatives, have arrived at an airport in western Japan to inspect a 787 jet that made an emergency landing earlier this week.

The All Nippon Airways jet landed Wednesday morning at Takamatsu airport after the pilot smelled something burning and received a cockpit warning of battery problems.

The four Americans, including an investigator each from the Federal Aviation Administration and the National Transportation Safety Board, met with officials Friday from the Japan Transport Safety Board, which is leading the investigation, said Mamoru Takahashi, a JTSB official.

ANA and Japan Airlines, which together have 24 of the Boeing jets, have grounded the planes. The U.S., Europe, Qatar and India also have done so.