Dutch Bru;
My point is that since the AF447 flight crew according to the BEA report did not ask for nor did they receive SIGMET updates by ACARS, they were disadvantaged in their awareness.
I would like to disagree and offer the view that this isn't something can easily be judged.
First, I would not like to think that just because a crew didn't ask for information that they were somehow "diadvantaged". We do not know what they were aware of; absence of requests is not evidence for absence of awareness.
As I stated, flight following is an airline dispatch function and part of that function is to send pertinent weather information via ACARS. It doesn't happen every trip nor does it need to.
A SIGMET is only an advisory. Awareness may begin with the receipt of same, but awareness of ITCZ weather is not predicated on such information.
The key understanding here and the reason I chose to respond is,
we
don't usually ask for SIGMETS enroute because we are already so-informed through our pre-flight briefing and are already well aware of air-mass weather enroute. It needs to be understood that SIGMENTS are not like ATIS messages which are issued every few minutes but in fact are usually hours old even when received for the first time in flight planning.
To be quite clear, no crew is relying solely upon the SIGMETS system for such awareness, and
certainly not when transiting the ITCZ - I submit that crews would have the radar on from the top of climb on, and build continued awaress through radar scanning, watching outside and listening on the common frequency - if a crew or airline pilot is waiting for someone else to describe the weather ahead, s/he don't belong in the cockpit.
For these reasons, this crew would be at
no disadvantage at all by "not requesting SIGMETS".
Planning weather diversions either early or when the line of thunderstorms begins to show on the 320nm scale is another matter. One does not strategize from SIGMETS except very broadly; operationally, one plans weather diversions using radar intelligently, based upon one's experience and knowledge. These are the areas in which questions should be asked, and I hasten to add that asking the question does not imply anything whatsoever.
PJ2