Originally Posted by Svarin
Each Flight Control Primary Computer will perform its own computations, and decide its own Flight Law, based on available data. FCPCs (or PRIMs) manage Normal and Alternate laws, while FCSCs (or SECs) manage Direct law. The Master PRIM (normally PRIM1) then decides which Law gets used for the whole system.
Basically, you can fly it in Direct Law with only one SEC remaining (all 3 PRIMs and 1 SEC lost). This aircraft has been fully certified in Direct Law.
Originally Posted by Svarin
This is unfortunately not accurate enough in our case. I urge you to reconsider the very particular case of FCPC n°2, after it lost connectivity with ADR1 following this failure :
02:11:55 EFCS1 X2,EFCS2X,,,,,,,FCPC2 (2CE2) / WRG:ADIRU1 BUS ADR1-2 TO FCPC2, HARD
This is definitely a wiring fault, where FCPC2 and ADR1 lose their connection.
Not sure what you are saying is right. If it is a wiring trouble, it is on BUS 2 without affecting BUS 1. This is also too much reading as ADR1 was also very likely declared unreliable to the master (PRIM1).
Originally Posted by Svarin
Lemurian, could you be so kind as to demonstrate with certainty that FCPC2 reached indeed a state where it operated in Alternate 2 law ? I am not so sure. Normal law would be the preferred mode even with only two ADRs, as long as they produce similar values.
There is not a single doubt that ALT2 was triggered from the begining of the sequence.
Originally Posted by Svarin
FCPC1 certainly did operate in ALTN2, as correctly demonstrated by BEA in its intermediate reports. It was Master PRIM until it failed along with its SEC1 partner :
02:13:45 F/CTL PRIM1 FAULT
02:13:51 F/CTL SEC1 FAULT
This is called a reset, not a failure.