Until Boeing provides a permanent software fix, airlines with 787 Dreamliners in their fleet will have to power down the planes once every 22 days.
A software glitch that could result in the loss of controllability for the 787s manifests itself after several hours of continuous use. The FAA says “all three flight control modules on the 787 might simultaneously reset if continuously powered on for 22 days.” Thus, a mandated reboot is necessary to prevent this situation from occurring.
The Seattle Times reports that it is unusual for a plane to remain powered on for more than one week.
“Boeing recommended that operators cycle power to flight control modules periodically to ensure overlapping resets do not occur,” Boeing stated in a release. “A permanent software fix is anticipated in the second quarter of 2017.” The Seattle Times stated there are currently 489 Dreamliners delivered to customers worldwide.