Hello Hazelnuts39,
Originally Posted by HazelNuts39
takata;
yes, I meant that one. BEA's 1st Interim report states it meaning as:
Quote:
Meaning: This message indicates a cabin altitude variation greater, as an absolute value, than 1,800 ft/min for five seconds.
As reported in its 2nd interim report, BEA has established that depressurization did not occur, therefore the Advisory means that the cabin was descending. That means that the airplane was descending, and that it was descending at a greater rate than the cabin pressuration system could cope with. Since cabin altitude in cruise is typically around 8000 - 9000 ft, I imagine that the Advisory probably means that the airplane was descending through an altitude in that range.
EDIT:: For structural reasons, the cabin pressurization system cannot allow the pressure inside the cabin to be less than the outside pressure. When that happens, the outside pressure will equalize the cabin, which then descends at the same rate as the aircraft.
Right, but what it means is that pressure varied, no more.
First, I didn't say that cabin was depressurized as I've read also the BEA reports and I'm fully aware that it is mentioned that no depressurization ever occured. What I'm saying is that everything is linked with frozen probes while many people around are just evacuating this factor for making wide assumptions about the flying conditions.
Consequently, variations of measured pressure are assumed to be the cause of cabin regulation issue. My opinion is that those variations are not the result of actual (real) pression difference. All systems that are going off, including this one, are feeded by unreliable informations comming from frozen probes.
I'm not assuming that F-GZCP's speed, altitude, pressures informations were still reliable after 02.10 when it is proved that they were not due to ice buildup. I'm not assuming that this aircraft was flying instantaneously below 14,000 ft near Mach 1, neither that she was instantaneously sinking at a rate of 8,000-9,000 ft because I firmly believe that it was simply the result of the root problem.
I'm not going to invent more issues than what is plainly documented as the primary root for many ACARS saying the same thing and which is ICE buildup. Furthermore, I'm also convinced that icing conditions were particularly severe and unusual due to the length of the convective zone crossed. It means that F-GZCP was certainly flying over huge tropical thunderstorms during about 15 minutes and that icing problems showed up after 2/3rd of the crossing.
Feel free to believe something else yourself but, please, do not contradict my points by ignoring this ICE issue. Furthermore, it is certainly possible to assume that problems with ICE did not end up there and that it could have caused dual engine flameouts when F-GZCP's ACARS transmission stopped.
In fact, my explanation is the simpliest possible: one factor, ICE, is identified and I certainly believe that it can bring this aircraft down all by itself, by accumulative effect. Each of those ICE related issues, taken one by one, were not such a big deal to be resolved by the crew but their accumulation in a short time, like a cascade, could have caused a final situation totally umbearable by the crew in this particular environment.
S~
Olivier