The European Aviation Safety Agency (EASA) issued an airworthiness directive (AD) mandating that operators conduct an on-ground power cycle at least every 149 hr. of continuous power-up. AD 2017-0129 was issued in response to reports of communication loss between avionics systems and networks. According to EASA, “different consequences have been observed and reported by operators, from redundancy loss to complete loss of a specific function hosted on common remote data concentrator and core processing input/output modules.” EASA’s—and Airbus’s—interim solution is to mandate a reset of the aircraft’s internal timer. The AD refers to Airbus Alert Operators Transmission (AOT) A42P001-17 for further instructions.
Credit: Pedro Aragau/Wikimedia
The tried and true “turn it off and on again” method has seen some success in the past—though the intervals of operation at issue were much longer. A 2015 FAA directive required a reboot of all Boeing 787 airplanes powered on for more than 248 days to prevent overflow of an internal software counter. A year later, software issues resurfaced when flight control modules on the 787 were found to reset automatically after 22 days of continuous power.