Clandestino;
I haven't found a "full report" on the Air Caraibe event. I don't think there is one.
Links to the
original (French). The English translation has been unavailable for some time. This
link takes you to an English version/discussion of the memo. It is close but not exactly the one I was able to retrieve a while back.
Been thinking about this respect the stall warning/ignore the stall warning matter....
The UAS QRH Drill / Checklist (dated Dec 01/08) states,
Technical recommendations:
– Respect Stall Warning, and disregard the “RISK OF UNDUE STALL WARNING” STATUS message, if displayed on ECAM.
– To monitor speed, refer to IRS Ground Speed, or GPS Ground Speed variations.
If remaining altitude indication is unreliable:
– Do not use FPV and/or V/S, which are affected.
– ATC altitude is affected. Notify the ATC.
– Refer to GPS altitude: altitude variations may be used to control level flight, and is an altitude cue.
– Refer to Radio Altimeter
The "Risk of Undue Stall Warn" message occurs on the STATUS page of the NAV ADR DISAGREE ECAM Checklist and occurs not on the ECAM page but on the STATUS page as an advisory message after everything else is sorted out. Here's what it says:
____________________________________________________________ __STATUS
– MAX SPEED ..............................330/.82______________|NOP SYS
_______________________________________________|____________ __|RUD TRV LIM
____________________________________________________________ | |CAT 3 DUAL
APPR PROC :
– FOR LDG ........................................ USE FLAP 3
This line is replaced by “FOR LDG : USE FLAP 3” when CONF 3 is
selected, as a reminder.
– LDG DIST PROC ...................................APPLY
Refer to the QRH 2.TOC.
CAT 3 SINGLE ONLY
RISK OF UNDUE STALL WARN
Undue stall warnings may mainly occur, in case of an AOA discrepancy.
RUD WITH CARE ABV 160 KT
The rudder travel limit value is frozen at the moment when the failure occurs.
Therefore, to prevent damage to the aircraft structure, use the rudder with care, when the speed is above 160 knots. At slats' extension, full rudder travel authority is recovered
The two messages shouldn't really be confused because the "Undue...etc" message is not seen on the ECAM until the correct ECAM SOPs have been completed for the NAV ADR ECAM.
The UAS Drill / Checklist and accompanying QRH notes is clear - Respect the stall warning.
The messages aren't contradictory but they can be made to appear so taken out of the operational context as I think the website to which I point, above, has.
That doesn't mean that it is not possible to confuse this! I think it is if one isn't paying attention. They're two different circumstances.
I frankly doubt if they had any training either way regarding whether to "respect the stall warning" or not. At the point they were at in the event that's pretty subtle stuff to be sorting out in the middle of all that was going on particularly the increasing anxiety.
If there were suggestions floating around that they may have picked up through discussion with other crews that "the stall warning could be false" and it "should" be ignored, that's a training, competency and cockpit discipline issue, not an ECAM/QRH issue I think. The message on every UAS drill I have is to respect the stall warning. We'll see what the report says, anyway...
PJ2