Originally Posted by
dcoded
Wasn't a similar issue discussed a couple of years ago already? That the AC needs to remain completely powerless. Or was it on another fleet, A350?
EASA AD 2017-0129 concerned unmodded A350 aircraft where various avionic systems stopped talking to each other after 149 hours of continuous power-up.
There was also a previous 787 AD in 2015 which related to a loss of AC power after a counter overflowed.