"It would be interesting to know whether that gap in something going wrong and the brain working out what extends on first flight of the day early morning ? "
A thought provoking question by PACE.
Humans are normally diurnal, that is to say active during the day, with circadian (24 hr biological clock) rhythm. There has been some medical research carried out under the banner of "chronotype".
It all seems very scientific and complex.
Not much there to help us to get an idea whether a morning lark type might be best for dawn flights and a night owl for dead eye flights.
After all the aviation industry, through the means of FTL have largely dealt with this matter.
Given the wx conditions on that fateful morning it would be reasonable to assume that the crew would have been fully alert, prepared to handle a t/o in reduced visibility and deal with any emergencies they may encounter, in accordance with their experience and training. There would ahve been the right level of adrenaline pumping around in their bodies. Whatever went wrong, must have been something which was outside and beyond their expectations, their knowledge, their training and experience. An event or a series of events, unexpected and not anticipated. Neither the early hour of the day, n`or the wx conditions would have altered the outcome. They were aware of both and were equipped to deal with these. Whatever occurred must have been so quick that even the so called sober as a judge could not have handled it. Yes some judges do appear to be asleep through most of the proceedings in their courtrooms, but it is only their eyes that are shut, their ears don`t miss a sigh or a murmur.
So I do not really think that a few early morning yawns could have been a factor.