From an industry newsletter:
The Availability Digest is published monthly. It may be distributed freely. Please pass it on to an associate.Managing Editor – Dr. Bill Highleyman firstname.lastname@example.org. © 2015 Sombers Associates, Inc., and W. H. Highleyman
Boeing 787 Could Lose All Power
The 787 Dreamliner is The Boeing Company’s newest addition to its fleet. Unfortunately, a software bug recently discovered by Boeing could cause the loss of all electrical power, potentially shutting down both engines.
A major goal of Boeing in the development of the 787 was to improve fuel efficiency. To achieve this objective, Boeing replaced many mechanical components with electrical systems to save weight. For instance, control services such as the ailerons, elevator, and tail that previously were pneumatically operated are now electrically operated.
Boeing recently discovered a software error in the generator control unit. The error could result in a total loss of electrical power to the aircraft with a consequent loss of airplane control. The condition occurs if electrical power is left on for 248 days without being turned off.
Fortunately, according to Boeing’s records, the electrical power for all 787s currently in service has been turned off as part of routine maintenance approximately every four months. The problem of electrical power loss has never been experienced by a 787. The FAA has now mandated that the electrical power of all 787s be recycled at least every 120 days, and Boeing is correcting the problem.