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Long Uptime Makes Boeing 787 Lose Electrical Power
jones_supa writes: A dangerous software glitch has been found in the Boeing 787 Dreamliner. If the plane is left turned on for 248 days, it will enter a failsafe mode that will lead to the plane losing all of its power, according to a new directive from the US Federal Aviation Administration. If the bug is triggered, all the Generator Control Units will shut off, leaving the plane without power, and the control of the plane will be lost. Boeing is working on a software upgrade that will address the problems, the FAA says. The company is said to have found the problem during laboratory testing of the plane, and thankfully there are no reports of it being triggered on the field.
It could be the overflow of a counter of 10ms intervals. There are 86400 seconds per day, so 8640000 10ms intervals per day ...
2147483648 / 8640000 = 248.55
If it ever happened on a plane, then it means that the maintenance was intentionally skipped. If they reach 248 days of continuous operation then a number of significant maintenance cycles have been skipped (some 23-25 inspection / maintenance cycles that generally require shutting down the electrical system). The generators in question are attached to the engines. The engines have a overhaul schedule that is shorter than 248 days of continuous operation. If they managed to reach this point, then the major maintenance cycles have been skipped and the engines are long overdue for a tear down inspection and overhaul. Any plane which could reach this point, 248 days of continuous operation missing all of the required maintenance; this is not a plane (or an airline for that matter) which anyone should be flying on.
Yes, but perform a clean systems shut down BEFORE turning off power.
I was on an airliner once that crashed at the gate, prior to departure.
Ground power was disconnected before they had spun up the APU. Lights out. Lights on. ... Several minutes later we get an announcement that we'd have to wait for a backup plane, which took 45 minutes to arrange.
They were unable to reboot the airliner.
Robust systems design wasn't a phrase that came to mind.