When one looks at the spectrum of accidents in which a mistake on the part of a pilot was involved, the ones who made mistakes were not from the less-qualified or less-intelligent side of the bell curve. They were, as a whole, no better or no worse than anyone else. An error on the part of a pilot, by itself, is not de facto evidence of a lack of competence, skill or judgment.
Several major airline accidents have occurred when pilots forgot to perform an essential task, such as setting flaps for takeoff. How should we think about these memory lapses—do they represent deficiency on the part of the pilots or inherent vulnerability of human cognitive processes interacting with equipment design and cockpit procedures?