Possible implications of CABIN VERTICAL SPEED ADVISORY (cont’d)
Bon soir takata,
Quote:
“Maybe the controller schematic. What ADIRU 1+2+3 are used for?”
To do its whole job, a CPC obviously needs to know the aircraft altitude (external static pressure), which it obtains from the AD part of the ADIRUs. It is also interested in the aircraft VS, and during aircraft climb and descent will adjust the cabin VS − for example if the aircraft VS is higher than expected − to keep the differential pressure at manageable values. These are the data it obtains from the ADIRUs. Their accuracy would be affected in the unlikely event of icing of one or more static ports.
Unfortunately, the schematic does not show where the CPC obtains the cabin altitude and cabin VS from. But these require, by definition, a sensor or sensors within the pressure hull. These presumably communicate data to the CPC and the FWC electronically. A loss of power could interrupt receipt, but received data should be valid.
Again unfortunately, I don’t have the exact criteria for the production of this advisory by the FWC, so am relying on other’s posts. These indicate that it is triggered by excessive cabin VS for at least 5 seconds, no other data being considered.
So I repeat my question: why do you dismiss this ECAM warning (sorry − advisory) as being spurious, or irrelevant?
Chris