FC, re your reasons (the answer is 42 – the secret of life and everything) – post #339, are those expected from a rational human, but again I suggest only in hindsight. What reasons (mitigations) could be provided for an ‘irrational’ human in the pre-accident situation. In this sense irrational is
‘the suppression of information directing a particular course of action’ (J. Reason). Reason (Human Error), continues: –
“erroneous behavior is more in keeping with past practices than the current circumstances demand”. Thus, your background, education, life events, or training might provide a degree of protection from irrational behavior.
However, what can be said (in hindsight) about other people. Even though it is reported that the accident Captain usually ‘followed the rules’, this external perception needs validating; we should remember that culture (mainly professional culture) is how we actually do things – ‘what we do when no-one is looking’.
I agree that ‘feelings’, those fundamental beliefs and biases, are strong behavioral drivers, which protect us from danger. Problems arise if we do not see the danger – we do not recognize the situation that we are in. A hazardous situation might be of our own making; thus, there could be strong mental drivers for us to believe it, similarly a plausible ‘situation’ could have been created by others.
I too hope that the reasons for the feelings (beliefs and biases) and the components of the situation are found, but with some of
BOAC’s skepticism I doubt that all of the human issues will be identified or even identifiable. The ICAO format for accident investigation with its factual approach and the reluctance of investigators to ‘speculate’ is unlikely to provide substantial recommendations to prevent similar accidents – the issues are predominantly human factors. How do you establish what a person’s perception was in a given situation, how to you determine ‘intent’ or ‘willful suppression of factors’ (Captain
and First Officer).
I suppose that if the industry had the capability to answer the questions above, the investigators at Burbank etc would have recommended specific defenses and there could be some hope that this and future accidents are avoided. Generally, the industry is presented with a loosely disguised conclusion of ‘human error’, blame, and recommendations for adhering to procedures (stabilized approach) and CRM (whatever one’s definition of that is).
I think that more investigative speculation would provide meaningful resources for safety action, which I hope in some small part this thread is doing. In this respect I also think that this supports
100%’s suggestion (post #340) to step back for a ‘broader look around’. As J Reason explains, there are two types of accident, those which happen to individuals and those that happen to organizations. I suggest that the 737 crew could have experienced a cognitive failure (not an accident), precipitated by organizational issues which would categorize this as an ‘organizational accident’. “One, which has multiple causes, which involves many people at many organizational levels, even outside of the organization”.
Runway overrun availability is relevant as it is part of the wider picture that may eliminate a component which contributed to the accident or its severity.
A similar, wide ranging view would be to compare the 737 with other aircraft – not necessarily just for the type or rate of overrun accidents. I recall that there was a comparison made between 737 and A320 for unstabilized approaches where the 737 was much more prone to high speed approaches. Along similar lines of thought, what type of ASI did the 737 have – mechanical, EFIS, strip or dial, – what was the crews experience with such an instrument? Answers to these ‘incidental’ questions often provide greater clarity in understanding and highlight some hazards to be aware of.
For some other ‘speculative’ defenses that may apply to this accident, see the thread on
TEM post #4.