From an earlier post by DozyWannabe
"Quote:
Originally Posted by Lonewolf_50
This takes me to BOAC's question about a crew allowing their aircraft to head into orbit: what airline pilot, flying at altitude, would find a 16 deg nose up attitude something other than abnormal?
Why would either let that nose attitude sustain?
This goes back to what may not be answerable: what did each member of that cockpit crew see in front of him, and what was he paying most attention to?
This is where (and why) I keep going back to Birgenair - where a very experienced pilot stalled and span his 757 despite the fact that the only fault on the aircraft was a single blocked pitot tube. It is impossible to know what was going through his mind, but nevertheless - even with both his F/Os calling "ADI" and "Stall" repeatedly, he apparently did not process the information that the ADI was giving him - that he was excessively nose high for the phase of flight he was supposed to be in. Attempts to remedy the other factors in that accident have been included in pilot training and bulletins from the manufacturers (and indeed a design change to the 757) over the years, but the fact remains that psychological factors in an incident of this nature are possibly not as well understood as they could or should be."
As a little exercise try to recite a nursery rhyme that you know well and at the same time read the text from DozyWannabe above and if you have a friend have them tell you a message that you need to write down.
You will find that you cannot do all these actions. You are overloading your brain's cognitive channel for verbal analysis. This is one of the reasons that using cell phones while driving reduces the ability of the driver - cognitive overload.
I have observed overworked controllers 'not see' aircraft fly past their tower due to overload like this.
Now what happened in the cockpit of AF447 appears to be a cacophony of emergency aural and visual messages from the ECAM. Many of the instruments that the pilots would rely on became invalid and others were showing totally unexpected outputs.
Saying the PF should have seen this or done that is easy when all these messages are teased out on a nice timeline - but when they are all at once nobody's brain can process them all. The response in the human under this pressure can often be 'cognitive or attentional tunneling' where everything except a small portion of the inputs to the brain are just not seen/heard.
Has anyone actually carried out a cognitive assessment of the PF workload when the AF447 series of failures actually occurred?
It seems to me that the aircraft didn't just say - 'You have the aircraft' - every system on the aircraft had to say something plus many of the instruments. The cockpit displays are not analogue gauges which use the spatial analysis cognitive channel, but are textual requiring the
same verbal analysis channel as the aural verbal messages and the ECAM text messages.
If there is a design area that needs assessment it is the way the aircraft can rapidly induce cognitive overload. It may be that the lack of discussion on the flight deck was caused by verbal channel overload. To go back to the start of my post: try holding a conversation with someone while carefully reading something different.
Perhaps this is the reason for the repeated
'set power and pitch' effectively saying disregard all those messages they aren't important -
fly the aircraft. The implication of this though is perhaps those messages that the designers and systems engineers thought were important
are not really important at all. They can actually lead to a worse outcome by overloading a flight crew that tries to listen.