VENT AVNCS EXTRACT FAULT 警告的不工作系统中，有 L AVNCS SMK DET 和 R AVNCS SMK DET。
空客解释为，烟雾探测探头是安装在排风管道里的，如果排风扇故障，就算有烟雾到不了排风管道，也就探测不了了。
TechRequest 原文
Q:
In VENT AVNCS EXTRACT FAULT, why there're L AVNCS SMK DET and R AVNCS SMK DET in INOP SYS?
A:
The smoke detectors for the avionics bays and electronic equipment are located in the ducts used to extract air from those bays and equipment. If the extraction is inoperative (No extraction by the fan or delta P possible), then the smoke detection reading is not possible any more.