Originally Posted by
hans brinker
Q: If the average applicant scores 100 points on the pilot qualification test, made up of theoretical questions, and a simulator check, you say they should probably normally distributed. Lets say 60 % score between 90 and a 110 points, and the airlines only hire the pilots with over 90 points. With the 20% percent who didn't cut it missing, wouldn't the resulting curve be non-normally distributed? (and seeing hiring rates around 50% at interviews makes me think the skewing would be worse)
Quite so. And while there will be an average level of skill for qualified pilots, the distribution is not at all likely to be normal, because you've selected the group, and the value will be pulled to the left by the sky gods.
Anyway, average is probably the wrong measure of central tendency. Better is almost certainly the median: by definition, half the population will be at or below the median value. Clearly, aircraft have to be readily manageable by the half of qualified pilots who fall below the median--especially aircraft like narrow-body twins, which are likely to fly the bread-and-butter routes that don't attract the profoundly gifted.
The issue, surely, is not to do with statistics, but with what the cut-off level is for getting, and maintaining, qualification (and it would be good if there were some measure of variability--you don't really want to have in charge of an airliner someone whose flying is sublime some days, but a total mare on others.)