Despite the talks of single pilot operations increasing in the aviation community and robotics treading into the spaces of baggage handling, the plain fact remains that humans remain pivotal in aviation. It is (human) researchers who perform flight safety operations; aircraft maintenance is done by humans, and so is plenty of work, such as quality assessment and duties of a cabin crew. However, each human being involved in these steps can have their judgment impaired due to a variety of factors. These are collectively known as human factors. Well take a few notable cases (alongside drawing parallels with others) and see how these factors can change the shape of aircraft operations, and aviation at large.