@
mm43,
Originally Posted by
mm43
Well, they did. Or at least the PNF announced the loss of speeds and later the change to ALT Law.
I agree sir that the PNF announced those 2 points, but as we see in the CVR transcript, no-one
mentioned (i.e. vocalised) the UAS process (memory items - decide whether needed or not, then QRH). If we accept (as I do), that there will be no
relevant words omitted from the transcript we've seen (e.g. I don't need to read any "last words" from the crew, if they said things to loved ones etc., so their omission wouldn't surprise me), then either they (especially the PF):
a)
did truly recognise the UAS situation, didn't vocalise that recognition, and forgot that there was a procedure to follow (IMHO unlikely);
or
b) did
not truly recognise the UAS situation for being that, and (this is speculation by me) treated it as some kind of unknown instrument / system failure, which they then got (terminally) bogged-down in trying to understand - which was not helped when instruments responded in unexpected ways when stalled, even though they were not faulty (e.g. low IAS due to high AoA affecting the pitot probes, leading to intermittent stall warning etc).
On the evidence I've read so far (in all the BEA reports and these threads), I vote for (b). This adds me to the list of other readers who believe that a explicit "You have a UAS condition! Follow the UAS procedure!" warning, may have helped, instead of the procedures
assuming that the UAS condition would be correctly recognised by every crew, every time.
As you have pointed out, adding such an explicit UAS warning could then lead to an attempt at automation keeping the "status quo" when that happens, although I see
that as a step of development beyond that of just giving a warning.
I'm sure some of the professional pilots will say that a trained ATPL pilot should not need that kind of "spoon-feeding", and I don't disagree. However for various reasons too long to explain right now, experience in my own (non-aviation) field makes me think this sort of explicit warning message should be seriously considered (not that Airbus or Boeing or any other manufacturers care what I think
).
Originally Posted by
mm43
I do find it "a bit of a stretch" to blame the systems/human interface when many similar situations have been successfully handled by other crews.
I respectfully disagree that "similar situations have been successfully handled by other crews" (depending on the subjective interpretation of "similar" and "successfully" of course
) as I explain here:
http://www.pprune.org/tech-log/46062...ml#post6673738
http://www.pprune.org/tech-log/46062...ml#post6747450
http://www.pprune.org/tech-log/46839...ml#post6804546
The BEA (in interim report 2, page 51 onwards in the English edition) discuss those UAS events with enough details to examine (13 to be exact). To quote myself from previously:
"Sure, none of the other flights crashed, but several were not handled according to the QRH, not all of them went into Alt* law meaning that subsequent actions cannot sensibly be compared to AF447"
The BEA explicitly mention the lack of other crews following the correct memory items, among other things. Therefore this looks much less like an AF447-only mistake IMHO, and makes the system/ human interface again an area where there should be focus, given that UAS events will continue to occur with current pitot technology.