In 2015 we learned that Boeing 787s needed to be turned off and on every 248 days. The problem was that the plane’s generators, powered on for over 8 continuous months, could fail and cause lack of control. The FAA issued an airworthiness directive to use the universal IT fix and Boeing went to work on a more permanent solution.
248 days == 2^31 100ths of a second.
even in 2015, our airplanes have integer overflow bugs https://t.co/6Z8d4y9gjM
— Fiora (@FioraAeterna) May 1, 2015
Now though we learn that the Airbus A350 needs to be turned off an on too.
Some models of Airbus A350 airliners still need to be hard rebooted after exactly 149 hours, despite warnings from the EU Aviation Safety Agency (EASA) first issued two years ago.
In a mandatory airworthiness directive (AD) reissued earlier this week, EASA urged operators to turn their A350s off and on again to prevent “partial or total loss of some avionics systems or functions”.
The revised AD, effective from tomorrow (26 July), exempts only those new A350-941s which have had modified software pre-loaded on the production line. For all other A350-941s, operators need to completely power the airliner down before it reaches 149 hours of continuous power-on time.
Bottom-line: Your IT help desk is right. There’s an Airbus software fix that needs to be installed but planes that don’t have it yet need to be turned off and on.