"Time Out" and "Captain you must listen" are "in band" signalling - the
attempt to establish the link uses the same part of the communications
bandwidth as the information content. If that (auditory) link is already
in use (R/T, stall warning, GPWS, annunciators...), and particularly under
conditions of personal stress, there is theoretical data (e.g. the Wickens
and Liu Conflicted Resourcing model) which says that these signalling
efforts may not succeed. In fact, as cognitive workload increases, the
chance of an effective interrupt probably decreases.
In these conditions it might be more effective to use a separate signalling
medium to set up the connection. Does anyone know of any operators who
advise, for example, that when using "Time Out" or an equivalent keyphrase
you should if possible supplement the phrase with a specific non-verbal
communication? Even turning to look at the person directly would arguably
make a difference. Any opinions on this point would be welcome.>>
Rick,
Though not a specific part of the procedure when using "Time Out", we advise
our students that physical touching with the message enhances its urgency.
That works well for the three or four forward cockpit crew members. Turning
to look at another crewmember during a high stress time is nearly impossible
given the seating arrangements in most aircraft and touching is pretty
impractical for those crewmembers in the back.
Training the whole crew to use the trigger words like "time out" or "Captain
you must listen" and the required reaction to them enlists not just the PICs
attention to a problem, but that of the entire crew. The desired reaction is
to change the focus of the crew's efforts. However, if the aircrew is in a
sufficiently dangerous or high stress situation, even screaming or hitting
may not be enough. Obviously, our objective is to get the crew to use these
tools before the situation reaches that kind of level. Hope these thoughts
are of some use
Regards
Dave Wilson
HTI