Spanair Flight 5022 takeoff crash
An MD-82 crashed on takeoff from Madrid-Barajas Airport after the crew failed to configure flaps and slats correctly, killing 154 of the 172 people aboard.
The damage was public. The root cause was preventable.
An MD-82 crashed on takeoff from Madrid-Barajas Airport after the crew failed to configure flaps and slats correctly, killing 154 of the 172 people aboard.
What the software actually got wrong
The Take-Off Warning System (TOWS), designed to alert the crew if flaps/slats were not set for takeoff, failed to sound because a relay in the system had also failed; investigators found the fault had gone undetected because the system had no independent way of confirming its own alerting function was operational.
The Take-Off Warning System (TOWS), designed to alert the...
The Take-Off Warning System (TOWS), designed to alert the crew if flaps/slats were not set for takeoff, failed to sound because a relay in the system had also failed
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.
Investigators found the fault had gone undetected because the...
investigators found the fault had gone undetected because the system had no independent way of confirming its own alerting function was operational
Requs AI Software FMEA traces this failure mode back to the system-level hazard it feeds, tagging it against the Common Defect Enumeration so it surfaces in review instead of in the field.
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.