2009-06-06 07:04:42 UTC
Has anyone found a reliable source of information on the exact nature of
the ACARS messages sent by the aircraft before/during the accident ?
I have heard a variety of speculation with regards to ice on pitots,
cabin depresssurisation, incoherent speed readings. I have heard that
the messages spanned a period of 3 minutes from one source, 4 minutes
I've looked at the french site
http://www.bea.aero (click on the "fr" button below the
letterhead/header to choose english).
as well as the brasilian site:
http://www.anac.gov.br/ (use google to translate from portugese to english)
But could not find any hard factual information.
It appears that there may be some credibility to the airspeed indicators
being dysfunctional as there is apparently some AD going out to pilots
telling them to disregard airspeed indicators if they go nuts. (wouldn't
that be part of basic pilot training ?)
However, getting the exact order and timing of those messages would be
important to get some educated guesses in (which the media seem so
incapable of doing). Having cabin pressure drop first before altitude
drops would be quite different from having cabin pressure drop at the
end, after the aircraft has floored the engines and pointed the nose
straight down and aircraft went supersonic before breaking up.
On a computer aircraft such as the 330, should the pitot cease to
provide good data during level flight under autopilot control, would the
computer go nuts and floor the trhottle to try to increase airspeed ?
Would it think there is a stall condition and immediatly point the nose
down to try to regain airspeed, and since airspeed would not go up,
would point nose down even more until the aircraft is going vertical?
Would an aircraft such as this 330 flighing a long ETOPS route be
equipped with GPS and whatever the equivalent of what used to be called
FANS-1 navigation ? Would the computer consider the ground speed given
by the GPS when checking for airspeed validity ?
Also, doesn't ACARS automatically include aircraft's position in its
reports ? Or are those omitted ? Seems to me that this should be made a
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