SLF here. As one who regularly puts his safety in your hands, I come humbly to your forum with observations and questions from the two current threads on the Turkish Airlines accident in Amsterdam, and the Emirates tailstrike and near-accident in Melbourne. (Moderators: I'm posting this in R&N as it relates directly to two threads here, and concerns what I think is an "item that may be of interest to professional pilots".)
Although the respective investigations continue, the preliminary reports and the lively armchair analysis on PPRuNe suggest that both the EK and TK cases involved serious errors by the flight crew. In the Turkish case, the crew failed to notice abnormally decreasing airspeed, resulting in a fatal crash. In the Emirates case the crew apparently used an incorrect aircraft weight in their take-off calculations, very nearly resulting in a fatal crash.
In both cases the mistake was serious enough, in itself, to cause a crash. And in both cases, there was no layer of redundancy to catch the mistake.
But the responses from pilots on the respective threads here have been curiously different. The emerging consensus on the TK accident thread is that the crew made an inexplicable and inexcusable error, all on their own. No systems/management failure, no fatigue issue, nothing. Some put it more bluntly than others, but the prevailing view is perhaps best summed up in this thoughtful comment from bjornhall:
Of course we all know that humans are susceptible to errors, the best pilots can make the worst mistakes, the system is only made safe by trapping and mitigating such errors, not by relying on them never occuring, etc etc etc. I doubt anyone contributing here lack that understanding.
But not monitoring airspeed on final is too basic to fall under the "to err is human" heading. The system shall be pilot proof, not idiot proof. Sweeping every display of pilot error under the same "human error" blanket risks making one blind to an industry wide training problem, if such a problem exists.
In contrast, the response to the Emirates accident has been more along the lines of "there but for the grace of God go I", with lots of discussion of the possible role of fatigue, management problems, etc. One gets the impression that, in the view of pilots, this is a very different and less serious sort of "mistake" than in the TK case.
In general, as far as I can see, there are three basic types of "mistake":
1. Deliberately ignoring or contravening procedures, cutting corners, etc (e.g. as in the Garuda 737 accident, for which the captain was recently jailed).
2. Mistakes that "anyone" can make (where "anyone" presumably means "any properly qualified and reasonably competent and experienced airline pilot").
3. Mistakes that, although inadvertent, are so egregious or just plain stupid that no qualified pilot should make them ever, in an entire career.
Type 1 is not my concern here, although I know there is another whole debate over the application of criminal sanctions in safety-critical fields.
Type 2 mistakes are, or should be, covered by a system of checks and redundancies, both human and mechanical, so that when (not if) they happen, they are caught and rectified without major consequence.
Type 3 mistakes have no such coverage, since they are to be "trained out" of the human, and are presumably thought to be so unlikely as to require no further precaution or remedy.
It is fairly clear that the "PPRuNe consensus" (if such exists) views the Turkish accident as a type 3 mistake. The consensus is less clear on the EK accident, but many of the comments seem to view it as type 2, and there is a lot of sympathy for the crew.
Why the difference? Is there a difference? And if the EK case really is a type 2 mistake, shouldn't there be redundant systems to catch it?