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Old 17th Dec 2015, 02:19
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Check Airman
 
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Originally Posted by Goldenrivett
vilas,

Are you sure they actually heard the stall warning?
See AF 447 CVR Transcript and note that between the following times that the ALT ALERT "C Chord" was sounding continuously.
2:10:20 - 2:10:51 = 31 secs
2:12:57 - 2:13:55 = 58 secs
2:14:02 - 2:14:20 = 18 secs

It appears that for nearly 2 mins of continuous "C Chord", no one bothered to cancel it.
If you look closely at the "ATC, other voices, warnings, remarks and various noises" column, the crew were saturated with continuous audio warnings.
The continuous "C Chord" was only interrupted by "SV Stall Stall", "Dual Input", "cricket", "sink rate", "pull up" etc.

The BEA have asked if the present stall warning noise alone is adequate warning due auditory overload.

See Final AF447 Report Suggests Pilot Slavishly Followed Flight Director Pitch-Up Commands | News: Aviation International News
"Another reason for having ignored the stall alarm could have been a matter of sheer perception, Troadec said. “Audio alarms are no longer heard in some situations,” he admitted. This has prompted the BEA to recommend the addition of a visual stall warning."

I don't think the crew actually "heard" the stall warning. I think they automatically filtered all those "distractions" out. They needed a specific stall warning attention grabber like a vibrator or buzzer felt through the side stick, not a flight deck saturated with noises like an orchestra warming up.
Completely agreed. The cockpit is quite ergonomic, but I've long had the opinion that Airbus went a step too far when they removed tactile feedback from the control system. They managed to interconnect the rudders? Would it have been prohibitively difficult to connect the sidesticks?

Interesting note about the altitude alerter. I'd have thought that the stall warning would have taken priority over all other audio alerts. At least they knew they were off their altitude...

Last edited by Check Airman; 17th Dec 2015 at 02:29.
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