Machinbird-Why couldn't the ADR problems be a result of a departure from controlled flight?
Svarin-Everything is possible but you will need a root cause for upset, for which there is no proof nor evidence. That is a gratuitous hypothesis, not Occam compliant at all.
I’m sorry. A potential root cause was proposed-a dynamic departure from controlled flight with two potential pathways for that to happen. I would not have suggested that the ADR problems might have resulted from a departure at the beginning of the ACARS sequence otherwise. There is also no absolute proof for the older BEA hypothesis either. I will say that the dynamic departure fits some of the observed facts better: The RTLU position, and the fact that on at least 3 cabin crew seats, no one was occupying them at impact. A dynamic departure would be rather violent-probably 3 half cycles.
Svarin-Both FPVs got flagged early in the sequence, and that means both guys at the front just switched their FPVs on and found them flagged. FPV is pretty useless in an upset and is definitely not the first thing you will do then. Beginning of sequence is stable flight, only condition when FPV is useful.
Bear with me, lets see what BEA says with reference to these. (I’m a steam gage guy, so I’ve not had an opportunity to use this type equipment.)
Lets look at messages relating to the PFDs (courtesy of MM43)
2:10:29
WRN/WN090601 0210 228300206FLAG ON CAPT PFD SPD LIMIT
2:10:41
WRN/WN090601 0210[228301206FLAG ON F/O PFD SPD LIMIT
Meaning: This message indicates the unavailability of the FMGEC’s
characteristic speed calculation function
2:11:00
WRN/WN090601]0210 28300106FLAG ON CAPT PFD FD
2:11:15
WRN/WN090601 0210 228301106FLAG ON F/O PFD FD
Meaning: This message indicates the Flight Director function is selected and unavailable.
2:12:10
WRN/WN090601 0211 341200106FLAG ON CAPT PFD FPV
2:12:16
WRN/WN090601 0211 341201106FLAG ON F/O PFD FPV
This message indicates that the flight path vector FPV) function is selected but unavailable. In order to lose completely this function, which is elaborated by IRs in a way that is compatible with the CFR, one of the following three conditions must be met for each ADR:
barometric vertical speed higher, as an absolute value, than 20,000 ft/min,
true air speed higher than 599 kt,
measured calibrated airspeed lower than 60 kt.
Once the operating conditions are satisfied again, the FPVs reappear on the PFD (if TRK/FPA mode is still selected).
Looks like the Flight director was already engaged at the beginning of the sequence. Do you guys use the FPV(bird) enroute too? If so, it could have been engaged at the beginning of the sequence but wasn't 'squawked' until the rejection criterea were met in the second correlation window. Maybe AF447 started down like a safe at that point? Then again maybe it was just airspeed effects caused by the departure.
Svarin-FMGEC1 gets faulted by AFS late in the sequence, and that means AFS is active. Which means it got reengaged, because it dropped early in the sequence due to UAS. This again says 'stable flight'. Flight was stable until this fault at least.
2:14:20
FLR/FR090601 0213 22833406AFS 1,,,,,,,FMGEC1(1CA1),INTERMITTENT
This message cannot be the trace of a reset which, in particular, excludes the possibility of a manual shutdown. This message could be the consequence of inconsistency between the two channels in the FMGEC (COM and MON). Such an inconsistency could be the consequence of erratic input parameter values.
In any event, the effects of such a message could only be the disengagement of automatic systems, whose associated cockpit effect messages had already been transmitted at 2 h 10. The “INTERMITTENT” nature of the message means that the problem lasted for less than 2.5 seconds.
Svarin-Last but not least, the whole ADR clusterphukk is due to Probe-Pitot faults early in the sequence. There is enough evidence of these particular probes icing in cruise to make this a reasonable root cause. Of course, there is something else to turn a manageable UAS into a crash from FL350.[/font]
Like MM43-I too wonder, is the ADR problem the chicken or the egg? We will need the black boxes to figure this one out reliably.