Airbus A350 149-hour software reboot bug
EASA issued an emergency airworthiness directive requiring A350 operators to power-cycle aircraft periodically to avoid a potential in-flight loss of key avionics displays and systems.
The damage was public. The root cause was preventable.
EASA issued an emergency airworthiness directive requiring A350 operators to power-cycle aircraft periodically to avoid a potential in-flight loss of key avionics displays and systems.
What the software actually got wrong
Similar to the 787's bug, a software counter in some onboard computers could overflow after 149 hours of continuous power, causing multiple systems to fail or blank out simultaneously.
Similar to the 787's bug, a software counter in...
Similar to the 787's bug, a software counter in some onboard computers could overflow after 149 hours of continuous power, causing multiple systems to fail or blank out simultaneously.
Requs AI Edge Case flags this exact pattern at the requirements and architecture stage — before a single line of code implementing it exists — so the assumption behind it gets challenged while it is still cheap to fix.
Beyond code coverage and "shall" testing
Root causes like this one rarely show up in code coverage or requirements-compliance testing, because nobody wrote a requirement anticipating the specific edge case that broke. Requs AI Edge Case and Requs AI Software FMEA are built to surface exactly this class of overlooked failure mode — before the software is written.
Surfaces this before code exists
Identifies edge cases like this one at requirements and architecture time, using the Common Defect Enumeration to catalog failure patterns seen across hundreds of real-world software failures — including this one.
Connects the failure mode to the hazard
Traces this class of root cause directly to the system-level hazard it can produce, so a defect pattern like this one gets flagged during design review instead of after it ships.
Find the overlooked root causes before they ship.
Schedule a demonstration, or explore how Requs AI Edge Case and Software FMEA use the Common Defect Enumeration.