Unnecessary Risk
The safety problem is not necessarily during the procedure, it’s more likely to be the decision to attempt the procedure (or even allow it) – these observations are made in hindsight.
411A suggests that judgement of ability is a factor “if you can’t bear the heat”. I disagree; how your personal performance can vary is a more realistic consideration. “It’s often the best pilots who make the biggest mistakes” (James Reason)
Similarly, the dependence on ‘all available resources’ will not protect against every error, particularly optical effects which can affect both crew similarly, or just the one with visual contact.
A better decision (hindsight) would have been to have held or diverted; preceding traffic appeared to come to this conclusion. Thus, why did this crew decide to make the approach? Complacency, they thought that they were better than they were, familiarity with a local airport, the weather changed, or they were just human – they suffered an error in awareness.
It’s unlikely that any factor in this area will be identified with certainty, or any deeper human reasons behind the decision.
I recall a quote “Don’t ask why the lights could go out; consider what you will do when the lights do go out”, which may relate to this thread where the focus of debate is on why the accident occurred.
An operational ‘technical’ investigation is worthwhile to a point, but the thread conclusions focus on how ‘this’ accident might be avoided by considering how the procedure can be done, as opposed to should it be attempted.
The judgement should consider how to avoid such situations – even if it’s within the charted limits, within the SOP guidelines, within your capabilities, or someone else has done it.
We all require a safety margin, which will vary with each situation, and thus requires our assessment of the situation on that day, at that time, and thence the choice of action.
This choice is not the minimum safe option; it should be the safest option – that which avoids ‘unnecessary’ risk. But what is unnecessary?
Meekal, “If he was not in TOGA mode then he got no terrain warning … ”
No, this is not necessarily a logical assumption. See the link in #262; any one of those aircraft could have crashed, they did not.
The key to understanding this accident is to look at how this situation (including crew decisions and action) differed from the non accident situations.