After a six-week suspension, Boeing will resume flight test activities today, though a complete assessment of the schedule will be completed in January and the status of the company's certification testing remains unclear.
Boeing says an "interim solution" for the 787's power distribution system software has been "verified through extensive testing" and has completed "a rigorous set of reviews to confirm the flight readiness of ZA004", which will lead the fleet back to testing.
Boeing will restart its testing in two phases, first, flying company-required tests that remain to be completed and later followed by a resumption of certification testing, says Scott Fancher, 787 programme vice president and general manager.
Formal resumption of testing for certification credit, however, remains unclear and Boeing says there are "lots of possibilities in front of us regarding conversations on certification testing" as the restart of testing gets underway.
Fancher says: "As we return to flight test and determine the pace of that activity, we remain focused on developing a new program schedule."
Boeing says testing with electrical system supplier Hamilton Sundstrand was completed on the interim software updates earlier this week.
"Additional ground testing will be done by the company on the production version of the airplane to further verify performance of the changes being made," the company states.
Of the final software fix, Boeing says the "production version will be more refined" and both versions will ensure "a quick response to any fault or arc and ensuring continued safe flight".
The production fix will be validated on the 787 test aircraft before the first production 787, Airplane Nine, makes its first flight.
The company halted test flights following the 9 November fire aboard its second of six test aircraft while it was on final approach to Laredo, Texas.
Airplane Nine achieved first engine start on 22 December, the company confirms, making it the first production 787 to reach that status.
Boeing had planned to hand over the first 787 in May 2008 to Japan's All Nippon Airways, but that handover has stretched nearly three years after extended delays pushed the most recent target to mid-first quarter 2011.