Hello everybody,
Originally Posted by PJ2
Takata;
Just for info....it is not possible to say without very detailed examinations and perhaps simulator investigations, that the CPCs would be affected by loss of just the 3 ADRs due to iced pitots only. I wondered about this but cannot determine it from the FCOM.
Some data may still be provided to the CPCs or it may not - the FCOM is very simplified and geared towards the flight crew "need-to-know" level. It is not entirely possible to confirm the effects of loss of just the static ports either, without a similar investigation.
I agree with that, and like many here, I don't have access to A330 simulator and can't say a lot more about it.
Nonetheless, as a recapitulation of my point: (1) cabin pressure controler need to be feeded by external data and those data are known corrupted by (at least) pitot probes freezing with a verified error range well above 1,800 ft per min. in absolute value = 30 ft per second. (2) ADIRUs 1, 2, 3 are used to feed the controler, and all three are supposed rejected. (3) this alert (at this point) is minor, only informing the crew that cabin pressure is to be controled manually.
Consequently, it is not possible at this point of the flight (02.13) to deduct anything from this ACAR about
:
1) Flight altitude;
2) Rate of descent/climb;
3) Depressurization issue.
i.e. This alert may be related to purely sensor/ADIRUs errors; it may be related to a real aircraft descent rate above 1,800 ft/mn from whatever altitude (in case external pressure is still feeded to the controler by another circuit - but whilch one?); it may be related to crew actions during troubleshooting...
But it doesn't mean that the controler was trying to regulate the cabin pressure at 7,350 ft or below. It is alerting the crew that the controler would be unable to regulate it automatically..
S~
Olivier