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Old 2nd Nov 2012, 13:22
  #117 (permalink)  
RR_NDB
 
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HF or Interface?

AvMed.IN sez



The vital factor at play in such cases could be low observability interfaces in novel (“nonroutine elements”) situations with operator caught in a bind while trying to track and anticipate the actions by the system in his hands! Simply put, when he (rather, they, being multi crew environment) is loosing the grip of the unfolding situation and finds himself inadequately prepared for the fast unwinding situation, which was chillingly evident in Air France Flight AF 447 as brought out in the final report [1]:-



“The accident resulted from the following succession of events: (I changed the sequence)

Temporary inconsistency between the measured airspeeds, likely following the obstruction of the Pitot probes by ice crystals that led in particular to autopilot disconnection and a reconfiguration to alternate law,

The crew not making the connection between the loss of indicated airspeeds and the appropriate procedure,


Inappropriate control inputs that destabilized the flight path,

The PNF’s late identification of the deviation in the flight path and insufficient correction by the PF,

The crew not identifying the approach to stall, the lack of an immediate reaction on its part and exit from the flight envelope,

The crew’s failure to diagnose the stall situation and, consequently, the lack of any actions that would have made recovery possible.


Simply put:

The Interface should provide immediate and precise outputs to the crew even during anomalies

A brief cold in AS probes could and should be reported in the very beginning of the cascaded events. Surprises should be always reduced to a minimum and in AF447 case the uncertainties certainly played an import role to the outcome.

So, Human Factors emphasis or the need for better interface?

Clearly both are important and are closely related.
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