Boeing 787 must be rebooted to protect against integer overflow

The Boeing 787 Dreamliner has a fairly noticeable software bug. Problems arise if the aircraft’s systems are not rebooted once every 248 days. Failure to do so may cause the electrical generators to fail.

The Guardian reports that the US aviation authorities have issued a warning. There is a problem with the four electrical generators that the Boeing 787 has on board. If they are switched on for more than 248 days in a row, they can switch to a ‘failsafe mode’, which means that all electricity in the aircraft can fail. Of course, that can have catastrophic consequences if the plane is in the air at that moment.

The problem after 248 days is probably related to a 32-bit integer overflow. Converted to the number of hundredths of seconds, the number of 231 is exceeded at 248.55 days. Incidentally, Boeing has not confirmed that an integer overflow is the cause of the problem.

There is a workaround, and it’s quite simple: the system needs to be rebooted. As long as it is restarted every now and then, the Dreamliner is safe to use, according to the aviation authorities. Boeing reports that it has now switched all its planes off and on again.

Until the fourth quarter of this year, airlines still have to reboot their Dreamliners. After that, a software update should come out that fixes the problem permanently. It is not clear whether that update will arrive over-the-air.