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Missing Files Blamed For Deadly A400M Crash
An anonymous reader writes: Think you had a bad day when your software drivers go missing? Rejoice, you get to live! A fatal A400M crash was linked to data-wipe mistake during an engine software update. A military plane crash in Spain was probably caused by computer files being accidentally wiped from three of its engines, according to investigators. Plane-maker Airbus discovered anomalies in the A400M's data logs after the crash, suggesting a software fault. And it has now emerged that Spanish investigators suspect files needed to interpret its engine readings had been deleted by mistake.This would have caused the affected propellers to spin too slowly causing loss of power and eventually, a crash.
The story seems to massively simplify how the ECUs work. Each engine needs to be calibrated after production so that the sensor data it hands to each ECU is actually meaningful due to the way it's actually acquired in the engine. The parameter set isn't stored in the engine, but in the associated ECU. To prevent them from getting out of sync, the engine itself contains a little register with the checksum of the parameter set. If that checksum doesn't match, the ECU shouldn't power up the engine. However, the register and the ECU are initially loaded with a default parameter set used in testing scenarios. Looks like that one might have been untouched for the engines on that flight. Now, this is bad because the ECU now misreads the true engine status in various ways and can even think that an engine which is otherwise running fine is seemingly in some critical condition - e.g. power output too high, which causes an immediate shutdown to prevent engine damage. A jet engine that fails by disintegration has a high chance of slicing other airplane parts with ripped off fan blades. This is why hard engine shutdowns do make sense. But when putting the pieces of this puzzle together, this is starting to look similar to how Murphy's law came to be: an exceptionally unlikely chain of human errors ruining everyone's day.