Originally Posted by Acute Instinct
The following protections appear to have been ineffective in this instance,
*Load factor limitation
The load factor limitation probably worked.
In clean configuration (which we assume in cruise) the aircraft can handle up to -1G. That'll pin you to the ceiling quite thoroughly if you're not strapped in. All within the designed load limits.
Even with slats extended, the negative limit is 0G, which will render everything weightless, and can cause considerable havoc.
*Pitch attitude correction
Didn't this work? PRIM was given (wrong) High AoA values, and lowered the nose accordingly.
*High speed protection
How is this relevant? I'm not aware that MMO was reached/exceeded ...
*Maneuver load alleviation(MLA)
MLA only becomes active when stick deflection is more than 8 degrees aft, and load is higher than 2G. Its purpose is to to alleviate structural load of the outer wing surfaces, while maintaining load factor. This is probably irrelevant here. The major upsets were downwards.
*Turbulence damping function
Turns out now there was no turbulence.
*System redundancy
This is interesting. As others have pointed out, there are 3 ADIRUs. Are there really no cross-checks to detect a failure in one?
Bernd