787 Design And Software Changes Follow Fire

Boeing is developing what it says are “minor design changes” to the power distribution panels on the 787 and adding updates to the systems software that manage and protect power distribution as a result of lessons learned from the Nov. 9 fire onboard test aircraft ZA002 in Laredo, Texas. It also expects to issue a revised program schedule within weeks, representing the seventh specific delay to the overall program timetable. “We have successfully simulated key aspects of the onboard event in our laboratory and are moving forward with developing design fixes,” says 787 vice president and general manager Scott Fancher. “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,” he adds. The investigation 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.” Boeing says the design changes will improve the protection within the panel while software changes also will be implemented to further improve fault protection. The company is “now assessing the time required to complete the design changes and software updates that are being developed.” A revised 787 program schedule “is expected to be finalized in the next few weeks.” Local news reports in Seattle suggest the unidentified foreign debris referred to by Boeing may be a loose washer which caused the short circuit or arc, rather than a misplaced tool as had been widely reported earlier this week.