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Old 3rd Jun 2009, 08:32   #639 (permalink)
NARVAL
 
Join Date: Jan 2008
Location: PARIS FRANCE
Age: 67
Posts: 52
Although the initial failure report in the automatic message seems to have been about electrical problems (I do not know which) and the "tree" of possibilities of systems degrading from there is a vast one, I have kept in mind since the sad news ot the accident the following facts:
the A330 is a beautiful aircraft but it has shown, again and again , very susceptible to probes icing, with the deicing system on auto (numerous reports). This leads to very rapidly presenting the crew with a very lame aircraft to say the least (I give you a factual example below, recent, on an A330, without comments). This has happened at high cruise altitudes, with no ICE alarm, with the heating on AUTO, and out of clouds in some cases...
"Light tutbulence. The speed indication on the right PFD falls suddenly from 280 to 100 knots in red tape for a few seconds Almost immediately the speed on the left PFD falls to green dot minus 15 knots with a speed trend of minus 50 knots. Red alarm A/P OFF ADR
DISAGREE, IAS DISCREPENCY, ALTN LAW PROT LOST, REAC W/S DET FAULT.
Then amber alarm RUD TRV LIM FAULT.
Then STALL STALL STALL with Toga Lock indication.""
The crew changes flight level, the captain pilots with the stand by instruments,
The speeds become normal again.
The status after that:
amber crosses on PFDs
W/S DET FAULT, ALT LAW PROT LOST, ADR DISAGREE et F/CTL RUD TRV LIM FAULT (2
NOGO).Plane in Alternate law
This shows how an unconfortable event (loss of airspeed indication) that would have been minor in, say , an A300, becomes a major headache in those very sophisticated cockpits. Just for information and not saying that is
a possible explanation...but lose electrics, and apart from dealing with retrieving the generators, you may have that kind of thing loaded on top...
My thoughts go to them all...
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