Although the Federal Aviation Administration approved Boeing Company’s certification plan for the redesigned 787 battery system, after thoroughly reviewing Boeing’s proposed modifications, the National Transportation Safety Board said Boeing didn’t inform investigators about what it planned to say in the March 15 briefing in Tokyo, which is “inconsistent with our expectations.”

On March 15, Boeing reps provided their own analysis and conclusions regarding the NTSB investigation but they apparently signed paperwork that “must refrain from providing opinions or analysis of the accident.”

The NTSB was not amused.

Boeing plans to demonstrate that the system will meet FAA requirements but they are also concerned with damage control.

The certification plan is the first step in the process to evaluate the 787’s return to flight and requires Boeing to conduct extensive testing and analysis to demonstrate compliance with the applicable safety regulations and special conditions.

The Jan. 7 fire in Boston was composed of three-inch flames on the front of the connector’s battery box.