Hi Denis,
Originally Posted by DenisG
Assuming that the sequence of events must not correspond to the sequence of incomings ACARS (as noted by BEA), but should be correct within a minute (BEA), I wonder then:
If ISIS (22FN-10FC) SPEED OR MACH FUNCTION (2 h 11) implies the a/c was between 4,000 and 14,000 by now, the impacting event must have occured before those first ARCARS were received, including the 1min error. Coming down from 35,000 to 14,000 should take a few seconds more before that event.
Well, I dont think that BEA noted that messages were randomly sent. It is explained in detail how it works and it is noted that order is not necessarily correct due to:
. class of message;
. window of correlation issue;
. aggregate of related message.
PROBE PITOT 1+2 / 2+3 / 1+3 (9DA) (02 h 10) is opening a window of correlation and is time stamped 02.10 from the time it is validated. Time stamping is +/- 30 sec., meaning it was validated between 02.095 and 02.105.
while ISIS (22FN-10FC) SPEED OR MACH FUNCTION (2 h 11) being time validated between 02.105 and 02.115 without opening any window of correlation. Both being the same class, there is no reason to change the order at all. Consequently, the SPEED or MACH function fault is the result of the PROBE fault, not the opposite. And its case for being rejected by the FCP is certainly the second one:
. static pressure value higher than total pressure value, which match pretty well PROBE issues. Note that time stamp is different from time of reception, the former being what the system recorded.
Originally Posted by DenisG
But I can only follow on, if I understand, why these 4,000 - 14,000 can be established from the ACARS.
I am trying to think through the possibility that those ACARS and probably pitot tubes incl. were perhaps one result of the decline, but not the cause of the decline, if the decline had begun some minutes before that, as an altitude of max. 14,000 at approx. 02h 10min (- 1minute) (if correct by BEA and I do not understand yet) would reasonate.
While I don't precisely understand also how this altitude range (4,000 ft) is derived from the function, it seems very unlikely that something serious happened before 02.10 and was not reported by ACARs. Moreover, at 02.10.34, an aircraft positional report was issued (but not published) which would have reported also altitude, heading and speed.
Then, if one think that F-GZCP crashed at 02.14, actual position searched is about 41 nautic miles from her last recorded position, a place possible to reach at nearly 500 knots. But it is in the opposite direction of its flight plan... how could she have "deep" stalled from her previous position to this point?
I don't think that any aircraft may deep-stall at 500 knots, losing 35,000 ft without depressurization, cover 40+ miles in 4 minutes, while making a 180 steep turn, and hit the water in one piece without horizontal speed!
Something is obviously wrong about that.
On the other hand, if she was still flyable at 02.14, she might have turned back as the (possible) impact site is about 25 nautic miles West from her previous line.