MM43>>>> I thought that 35YearPilot in Post #1751 had explained rather well the Alternate/Direct Law relationship that gave rise to the engine protections adopted. The Eng 2 first mentioned in the following, seems to be a typo, and he was referring to Eng 3.
Thanks MM43, you are correct. Post 1751 has been corrected.
rob_ginger
The FG (Flight Guidance) calculates the TPR! The FG is contained in the PRIM flight control computers. With > 40 wiring loom faults (breaks) logged - get the picture?
BTW: If you lose the PRIMs (so the FG), then the TLA and Altitude is used (within the EECs) to calculate an N1 demand. (GenFam 7-5). QF 32 was in Alternate Law (from the PRIMs.)
The A380 PRIMs are remarkable beasts. I think their architecture is unequaled in any other flying aircraft. If you think this incident suggests otherwise, then consider that the event was a "boundary case" of
PR 10^-9 to 10^-12.