A350 除了有物理的 FCU 控制面板，在 MFD 中还有控制页面作为备份。所以在不正常程序中就涉及是一个故障还是两个都故障的问题。在 AUTO FLT AFS CTL PNL FAULT 警告中已经有一种情况是"If FCU BKUP is available on the CAPT (F/O) side only"，但是还有一个警告是 AUTO FLT AFS CTL PNL+CAPT(F/O) BKUP CTL FAULT，感觉就是重复的，没有必要存在。
空客在第二次回复中给出了一个可以接受的解释：AUTO FLT AFS CTL PNL FAULT + CAPT (F/O) BKUP CTL FAULT 会在失去 CAPT(F/O) AFS BKUP CTL 的供电时被抑制，而 AUTO FLT AFS CTL PNL FAULT 不会因为电气故障而被抑制。具体请参考 TechRequest 原文：
Q8: AUTO FLT AFS CTL PNL FAULT
This alert already contains the case "If FCU BKUP is available on the CAPT (F/O) side only" , why there's another alert AUTO FLT AFS CTL PNL+CAPT(F/O) BKUP CTL FAULT?
A8:
We would like to inform CSC that the AUTO FLT AFS CTL PNL FAULT is inhibited when AUTO FLT AFS CTL PNL+CAPT(F/O) BKUP CTL FAULT is triggered. Therefore, the two ECAM alerts are not redundant.
Q8_2:
Now that AUTO FLT AFS CTL PNL FAULT is inhibited when AUTO FLT AFS CTL PNL+CAPT(F/O) BKUP CTL FAULT is triggered, there's no necessary to list a condition "If FCU BKUP is available on the CAPT (F/O) side only :" in AUTO FLT AFS CTL PNL FAULT.
A8_2:
Airbus has reviewed CSC’s query and we would like to provide you with the following information:
In most cases AUTO FLT AFS CTL PNL FAULT + CAPT (F/O) BKUP CTL FAULT will inhibit AUTO FLT AFS CTL PNL FAULT when at least one FCU BKUP is seen faulty. The only time where this does not happen is in case of specific electrical failure. AUTO FLT AFS CTL PNL FAULT + CAPT (F/O) BKUP CTL FAULT is inhibited in case of loss of power supply of CAPT(F/O) AFS BKUP CTL while AUTO FLT AFS CTL PNL FAULT is never inhibited due to electrical failure.
So, if we have a loss of power on one of the AFS BKUP CTL power supply, the alert AFS CTL PNL FAULT will trigger and will help the pilot by pointing out the remaining FCU BKUP.
