Boeing has begun instituting what it called minor design changes to power distribution panels and updates to the systems software that manages and protects power distribution on the 787 Dreamliner. An investigation into the November 9 electrical fire aboard the second test airplane in Laredo, Texas, revealed the need for the changes, according to the company. Boeing hasn’t yet publicly shared any conclusion on the extent of further delays to certification.

“We have successfully simulated key aspects of the onboard event in our laboratory and are moving forward with developing design fixes,” said Scott Fancher, vice president and general manager of the 787 program. “Boeing is developing a plan to enable a return to 787 flight-test activities and will present it to the FAA as soon as it is complete.”

Engineers have determined that the fault began as either a short circuit or an electrical arc in the P100 power distribution panel, most likely caused by the presence of foreign debris. The changes will improve the panel’s fault protection, said the company.  The P100 panel serves as one of five major power distribution panels on the 787. It receives power from the left engine and distributes it to an array of systems.

The 787 team continues to assess the time it will need to finish the design changes and software updates, said Boeing, adding that it expects to issue a revised 787 program schedule in the next few weeks.

“Our team is focused on developing these changes and moving forward with the flight-test program,” said Fancher. “The team in Laredo is also well along in preparing to return ZA002 to Seattle.”