Humans are fallible – pilots are humans (for the most part, anyway) – therefore, pilots are fallible. What’s interesting is that when those humans/pilots are deprived of one or more of the things that “make them whole ‘n healthy” … like adequate nourishment, adequate hydration, and adequate rest/sleep; or if those humans/pilots are put into a circumstance where they are to be closely monitored and their resulting performance will have potentially significant ramifications; or if one of these humans/pilots has some significant personal circumstance (death in the family, birth of a child, just won the national lottery) … or some combination of the preceding … it isn’t wholly abnormal to see a pilot make a mistake (perhaps more than one), and, also depending on what kind of circumstance that individual may have been exposed to or deprived of … it is increasingly likely that the commission of an error may, in fact, go unnoticed.
Now if that error is something that has historically been a “habit pattern,” particularly throughout training, the individual may have been demonstrating a behavioral tendency in development, where, perhaps, that tendency was either compensated for by an unusual intervention (like an instructor or flying partner mumbling a memory jogger … like … “OK, we’re settling into the slot nicely now, looking for (and then casually mention either a power setting or rate of descent), and 100 feet over the threshold…” and doing so in a tone of voice that isn’t terribly noteworthy. As a result, it just may be that the individual may not pick up on the fact that he/she has become overly dependent on that nonchalant cue (whether it was verbal or something else) … so much so, in fact, that unless he/she is razor sharp, fully rested, fully awake and cognizant, properly nourished and hydrated, with his/her mind fully riveted on the task being accomplished at the moment, that unrecognized and unresolved potential “habit pattern” or “behavioral tendency” could be the making of yet another “pilot error accident.”
These kinds of tendencies are more prevalent than some may recognize or want to acknowledge … but they DO exist … and it is the instructors’ mission to notice, and correct, those kinds of developing tendencies. With a proper understanding of how to recognize such habit patterns or behavioral tendencies, and an understanding of what to do, as well as when, where, and how to do it, a successful intervention can definitely be accomplished to the degree that such tendencies might not ever raise their sometimes “ugly heads” again. BUT, that takes instructor awareness – and that almost always requires really good instructor training. If those kinds of instructors are developed and used, the frequency with which line pilots return to the “training school” should be sufficient to negate the development of any newly developing behaviors or habits that might, without proper training, develop into the makings of an accident or incident.
Almost no matter how you cut it … training is going to be the bottom line mechanism that we all can and should be prepared to use to at least maintain, if not improve, the safety level we all desire.